CISON V8 Engine Model Owners Speak: Real Detailed Tips & Solutions | Stirlingkit

CISON V8 Engine Model Owners Speak: Real Detailed Tips & Solutions

Introduction

Welcome to the ultimate guide for the CISON V8 engine model! This blog collects real questions and solutions from users who have hands-on experience with the engine. Whether you’re assembling it for the first time, troubleshooting ignition issues, or planning upgrades, this guide is designed to help you get the most out of your CISON V8.

This is a living guide – Stirlingkit will continue updating it as more users share their tips and experiences.

1. Assembly

Question: How do I get the O-rings in the block so the cylinder sleeves fit properly?

Problem:
“I’m struggling to get the O-rings in the block so that the cylinder sleeves fit correctly. They keep catching, and I’m worried about causing water leaks or damaging the O-rings.”

Answer / Solution:
Getting the cylinder sleeves in with O-rings can be tricky, but several users have shared effective techniques:

Grease the sleeves:

Apply a small amount of red grease or any light lubricant on the sleeves before sliding them in.

This prevents the O-rings from catching and protects against water leaks.

Work in a circular motion:

Gently rotate the sleeve in a circular motion while inserting it to help the O-rings seat evenly.

Patience and persistence are key—don’t rush it.

Use small tools carefully:

Tools like tweezers, toothpicks, or a small coat hanger can help guide the O-rings into place.

Be careful not to pinch or damage the O-rings while adjusting.

Hold O-rings in place if needed:

A tiny dab of grease on the O-ring can help it stay seated while you slide in the sleeve.

Following these steps ensures the O-rings stay intact, prevents water infiltration, and makes sleeve installation much smoother.

Tip: Always take your time and work carefully. Rushing can easily damage the O-rings or misalign the sleeve.

Question: How do I get the O-rings in the block so the cylinder sleeves fit properly?

Problem:
Hoping for a little help here. As shown there is an oblong recess on the right hand side of the connecting rod to keep the rod and cap mated correctly as shown in this photo. If I understand correctly the instructions say to have all of these facing in the same direction meaning towards the front of the engine or towards the back of the engine? Not sure why it mentions crankshaft and four links? This would mean the holes on the side of the rods (one on each rod) would be facing up towards the cam andon half of them and 4 of them would be facing down towards the oil pan on the other 4 rods. I’m not entirely sure what those holes are for but similar holes are used on the connecting rod caps on full-size engines and they always point up towards the camshaft for lubrication of the cam. I have included a photo of three pistons together showing the hole I’m speaking of on the side of the rod and the other two examples show one being faced up and one being faced down, showing the missing hole on the side of the rod. Hoping someone can help me out with what it means and why it’s necessary.

Answer / Solution:

All connecting rod oil holes need to be pointed up toward the camshaft so oil can properly splash and lubricate the crankshaft and rods. Fast forward to time 6:50。 The marks on the rods can face forward on one side and to the rear on the other, but ignore instructions suggesting grooves face front or back, as that is misleading. Ensure all rods are seated correctly without binding; this guarantees proper lubrication and smooth engine operation.

Question :

“Putting the new CISON V8 together it calls for a piece of adhesive under the front and rear of the intake manifold. It says it is in the plastic bag. Of course I don’t have this mysterious piece of adhesive. What are other builders doing under front and rear of intake manifold for a gasket?”


Solution:
The “mysterious” adhesive pieces are actually two short black pieces included in one of the parts bags. Builders glue them into the grooves under the front and rear of the intake manifold. A small drop of thin CA (cyanoacrylate) glue is sufficient to hold them in place before installing the cord. This creates the proper seal and ensures the manifold is correctly mounted.


Problem

Tech tip: Since there is a high likelihood that we have a lot of new people who recently received their first Cison V8 kit and will be assembling them, I would like to point out a small detail to pay attention to when they are assembling their engine. I haven't seen this one mentioned before or at least recently if it has.
Like the instructions say, the fit of the connecting rod big ends needs to be test fit to the crankshaft journals to make sure that the fit is not too tight. If the fit is too tight then add one shim at a time. Make sure to pay attention to the orientation of the shim. The shims are not square. The pictures attached to this post demonstrates this. Be sure to orientate the shims so that they the longer length of the shim is perpendicular to the crankshaft journals. If you don't, then the shims will rub the journals and destroy the machined surface. One last suggestion, it is easier to test fit the connecting rods to the crankshaft journals prior to installing the crankshaft in to the cylinder block. Just number the rods or pistons (if already assembled) and pay attention to their order and shim quantity when doing the final assembly in the engine block.

Answer

Thanks for bringing this up — this is a small detail that many first-time builders miss, but it matters a lot for long-term smooth running. Here are a few clear tips to follow when assembling your CISON V8 connecting rods:

Test-fit the big ends first.
Before the crankshaft goes into the block, slip each rod onto its journal and check that it rotates freely. If the fit is too tight, add one shim at a time.

Pay close attention to shim orientation.
Our shims are not perfectly square. The longer side must sit perpendicular to the crankshaft journal. If it’s rotated the wrong way, the edge can rub the journal and damage the machined surface.

Keep each rod assembly together.
Once you find the correct shim spacing, keep the rod, cap, and shim set together as one matched assembly. If you disassemble later, reinstall them in the exact same position.

Oil hole direction matters.
The small oil hole on each connecting rod should point toward the camshaft (the center of the engine). This ensures proper splash lubrication.

About “honing” the rod:
Yes, on real automotive engines this is how rod clearances are set. But most hobby builders don’t have the equipment to do this accurately. That’s why our kit uses shims — they’re reliable, simple, and beginner-friendly.

Pro tip for easier assembly:
Many experienced builders pre-fit all rods to the crank journals before attaching the pistons. This gives you more room and prevents mistakes.

If you ever find shims missing due to packaging or transport, just contact Stirlingkit support — we’ll send replacements free of charge.

Problem


What kind of tools and lubricant and other stuff so I can build a Cison V8 engine any tips?

Answer
To build your Cison V8 smoothly and avoid the common beginner frustrations, here’s the exact setup we recommend—the same checklist many experienced builders use:

Precision electric torque driver+ full bit set
Prevents stripped screws and keeps every fastener tightened to the right spec.

Fine-tip tweezers & long-reach ball-nose Allen wrenches(metric)
Essential for those tiny bolts tucked in tight spaces.

Blue & Red Loctite
Blue for removable parts, red for high-vibration components — keeps everything secure once the engine is running.

Assembly oil & Permatex gasket sealer
Helps the engine turn freely during assembly and ensures every seal holds vacuum properly.

Acetone/alcohol wipes for surface cleaning
Clean parts = better gasket sealing and fewer air-leak issues.

X-Acto knife set + general hobby tools
Handy for trimming boots, cutting tubing, and small adjustments.

Magnetic parts tray
Keeps tiny screws from disappearing (just keep it away from electronics).

Extra fluorine rubber bands(optional but highly recommended)
Perfect spares for piston sleeve rings and intake seals — better vacuum, easier first start.

or you can just buy the tools from Stirlingkit directly from here.

And the most important “tool”: patience and careful step-by-step assembly.
Our manual isn’t perfect in translation, so take your time — and if anything feels unclear, you can always reach out to Stirlingkit support. We’re here to help you finish the build and get that V8 roaring.

Sure! Here’s the same answer in a professional, customer-friendly English version:

Problem

“The instructions for the V8 oil ring are confusing—should the beveled sides face up or down? The pictures and text seem contradictory. ”

Answer

Thank you for your interest in the Cison V8! For the oil rings: the beveled edges should face the top of the piston. This ensures proper oil flow to the crankshaft and connecting rods for correct lubrication. The manual images and text can sometimes be confusing due to translation differences, and we are actively working on improving this documentation.

if any parts arrive damaged or missing during transit, you can contact Stirlingkit to have replacements sent free of charge.

Tip for assembly: carefully test-fit each component, pay attention to oil holes and ring orientation, and use a small amount of assembly oil if needed. This ensures smooth assembly, proper lubrication, and long-term engine performance.

In short: beveled edge up, follow the oil hole and part orientation, and contact us if you have missing or damaged parts—you’ll be ready to enjoy the full performance of your Cison V8.



2. Startup

Question 1: My engine has spark but won’t start. Why?

Problem:
“I have the version with the distributor that rotates with the accelerator to increase spark advance. I’ve tried various adjustments, but it doesn’t seem to give any signs of life. There are sparks, but it doesn’t make a bang even if I put gas directly into the cylinder.”

Answer / Solution:

Check the rotor position. Remove the distributor cap and confirm the rotor points at 6 o’clock during the compression stroke of cylinder #1.

Make sure the CDI light is on at the right moment (red for standard, green for Pro).

If misaligned, loosen the distributor, rotate it, reposition it to 6 o’clock, and double-check the ignition timing.

Install the upgrade electronics (Hall Sensor + rotor) that came with the engine for optimized timing.

Adjust your fuel mixture slightly lean for better startup.

“After installing the new electronics and trying a lean mix, my engine finally started. The only minor flaw was a little water pump leak, but it ran beautifully!”


Question: My new CISON V8 Pro engine won’t start. Sparks and fuel seem fine, but there’s no ignition or pop. What could be wrong?

Problem:

My new Cison V8 Pro engine won't start. It doesn't even make a single pop. I've checked everything, but it's just not working. Sparks are coming, and fuel is coming. The ignition advance is about 5 degrees before top dead center. Anyone have any suggestions?

Answer:

Distributor / Ignition Timing:

Incorrect distributor setup is a common cause.

Check if the rotor contact point points to #1 cylinder.

Make sure the distributor is not 180° out of phase.

The spark should occur just before TDC on the cylinder with both valves closed.

Remember: at TDC, two cylinders are at top dead center—one with valves open (exhaust/intake), the other with valves closed (power stroke). Spark must fire in the correct cylinder.

Valve Timing / Cylinder Setup:

Check valve timing: remove the #1 head and observe exhaust valve opening. It should be near BDC (bottom dead center).

Being off by even one gear tooth can prevent ignition.

Compression:

If compression is low, ignition may be difficult or impossible.

Ensure cylinder head and gaskets are correctly installed.

Fuel Mixture / Carburetor Settings:

Fuel mixture that is too lean or too rich may prevent ignition.

Recommended approach:

Start with fuel needle fully closed.

Gradually open in small increments until the engine shows signs of life.

Avoid starting rich, as flooding can make ignition impossible and waste time adjusting.

Spark Under Compression:

Verify that spark occurs inside the cylinder under compression.

If the spark only occurs in free air, the engine won’t ignite because arc resistance is higher under compression.

Question: Gearbox and clutches keep causing problems—how can I fix them without constant disassembly?

Problem:

“I’ve tried different ignition timings and various needle settings, checked the compression, made sure I get sparks on all cylinders but my Cison V8 still won’t run. When I feed propane into the carburetor intake port, the engine starts for a second then stops. I’m considering replacing it with an RC plane carburetor — is this worth trying?”

Answer / Solution
Here’s what I’d suggest based on what other Cison V8 owners have done:

Check your carburetor assembly: Some engines come with the fuel intake block upside down, which blocks fuel. Make sure everything is oriented correctly.

Inspect the needle valves: Both the low-speed and high-speed needles need to screw in fully without wobbling. They should completely stop fuel flow when fully closed. Many engines are overly rich because the needle passes too much fuel.

Fuel mixture and type: Use proper gasoline or Coleman fuel. Start with a lean mixture and gradually enrich it — flooding is very easy on these engines.

Alternative carbs are a last resort: You can use a glow engine carb with an adapter, but it won’t behave perfectly with gasoline. Usually, the original carb is enough once everything is adjusted and sealed properly.

Watch for heat effects: Make sure the carb is insulated from the manifold; too much heat can vapor-lock the fuel and prevent running.

Be patient with factory quirks: Some engines arrive with missing screws, damaged parts, or CDI issues. Double-check every step before assuming the carb is the problem.

Bottom line: Before trying a new carb, make sure your original one is correctly assembled and the needles are functioning. Most people get their engines running once the carb is set up properly — no need to switch to a glow engine carb unless you really can’t get it right.


Question: Gearbox and clutches keep causing problems—how can I fix them without constant disassembly?

Problem:

“After yet another disassembly of the Cison gearbox without having really solved all the problems it creates with those stupid clutches, I am seriously considering the idea of creating a hybrid with a traditional gearbox and centrifugal clutch. The only regret is for the external case which is very beautiful…”

Answer:

The main problem is usually a too large gap between the 2nd and 3rd gears, which makes the clutch plate slip. You can fix it by moving a shim from the front of the 2nd gear to behind it, and if needed, add an extra shim. This keeps the clutch plate in place and makes the gearbox run smoothly. It’s still a bit of a hassle to remove the gearbox from the model, but once adjusted, it works reliably.

Question 2: On my Pro version, the light is green – is this normal?

Problem:
“Is the new Hall sensor and rotor cap different? On mine it is the green light that comes on when it is set up as described.”

Answer / Solution:

The Pro version uses a purple rotor top with a south pole trigger, causing the green light to indicate ignition for cylinder #1.

The green light is normal; the standard version uses red.

No need to worry—your engine is working as intended.

Question 3: How do I know the distributor is aligned correctly?

Problem:
“I’m not sure if my rotor is pointing the right way. How do I check it?”

Answer / Solution:

Remove the distributor cap. The rotor should point at 6 o’clock during the compression stroke.

Observe the CDI light: red for standard, green for Pro.

Proper alignment ensures reliable spark and avoids startup issues.

Question: Which battery and connectors should I use for the CISON V8, and how do I wire them?

Problem:
“I’m confused about which battery and charger to use. The instructions aren’t clear about the connectors: the plug on the right, the red and black connectors—what do they plug into and how?”

Answer / Solution (Summarized Tips):
To get your CISON V8 powered correctly and safely:

Right-side plug: Connects to the starter. This is the main power input for starting the engine.

Red JST plug: Powers the CDI ignition system. Must be connected to a battery source to operate the engine properly.

Black connector: Connects to a tachometer (RPM gauge) if you have one; otherwise, it can remain unconnected.

Multiple connectors from one battery: Use a splitter if you want to power both the CDI and starter from the same battery.

Circuit separation: The starter and CDI are on separate circuits—do not mix them.

Battery selection: Choose a battery that provides stable voltage and sufficient current. Standard RC batteries from eBay or Amazon usually work fine.

Tip: Double-check polarity and connector orientation before powering up. Proper wiring ensures smooth startup and avoids damage to the electronics.

Following these guidelines, your CISON V8 should start reliably, and all electronic components will work as intended.

Question: What’s the best way to make connections for the spark plug wires on the CISON V8 Flathead?

Problem:
“I’m looking for a better way to connect the spark plug wires. The original cylinder spring clamps feel loose and don’t give a realistic snap, and I can’t find proper spark plug boots and clamps online.”

Answer / Solution :

The original spring clamps can feel loose and lack the tactile “snap” of real spark plug connections.

Some users have handmade new clamps for the ignition wires to ensure a tight and secure fit on the spark plugs.

A good spark plug connection should:

Push on easily but hold firmly.

Pull off without damaging the wire.

Give a satisfying click/snap to indicate it’s locked in place.

Handmade or custom clamps can improve both functionality and realism, giving the engine a more authentic feel and preventing accidental disconnections during operation.

“Better hand-made clamps ensure the wires stay locked onto the plugs while also providing a realistic feel, much more satisfying than the original spring clips.”


Question: How do I install the alternator on the CISON V8?

Problem:
“I’m not sure how the alternator mounts on the V8. Where does it attach, and what about the chip and voltage stabilizer?”

Answer / Solution (Summarized Tips):

Mounting: Attach the alternator using the curved bracket.

Secure it to the bolt that holds the oil pump.

Use the provided washers to properly space the alternator away from the belt wheel.

Electronics:

Check which chip you are using: the alternator may come with a round or square chip—install the correct one according to the instructions.

If your setup includes a voltage stabilizer, make sure it is installed properly to protect the electronics and ensure stable output.

Proper installation ensures the alternator runs smoothly, charges correctly, and avoids interference with the belt or other moving parts.


Question: Is the Cison V8 engine stalling at high RPM and high temperature, with fuel backflow from the tank making it difficult to run smoothly?

Hey guys, I am still struggle to get the V8 running... Maybe somebody have an Idea for the Issues, because I already trying to fix this for a month now...
1. I cannot rev higher than 3000. (it turns off) I tried everything, with the LSN and HSN, in parallel. I am out of ideas... idle running as long its not on temperature seems to be good!
2. As soon as the engine reaches higher temperature (around 70 degrees) it turns of and its really hard to keep it running afterwards. Even with higher idle speed oder adjusting the LSN (see video)
3. maybe this is normal but as soon the engine is on temperature the gasoline seems to be running back to the fuel tank. And its really hard to get the engine start. Its easier to wait until the engine gets coder and then start it again...
Looking so forward for help

Answer:

If your Cison V8 struggles to run properly, especially at higher RPMs or when hot, here’s a detailed guide based on community experience and engineering principles:

1. Fuel Delivery & Tank Placement
Cison V8 carburetors are gravity-fed, so ideally, the fuel tank should be above the carburetor. This ensures consistent fuel flow. However, some users report that even with the tank slightly below the carburetor (e.g., 4 inches), the engine can still experience fuel backflow and shut down at higher temperatures. This shows that tank placement alone isn’t always enough. Make sure your tank is properly vented, all fuel lines are secure, and there are no leaks that could affect fuel flow.

2. Needle Adjustments

Low-speed fuel needle (LSN): Slightly increasing it by 0.3–0.5 turns can help stabilize idle and prevent fuel starvation at low RPM.

High-speed fuel needle (HSN): Too many turns can cause fuel backflow. Check that the HSN is properly set and that the needle seat is not leaking.

Adjust incrementally: small adjustments make a big difference.

3. Hall Sensor Check

Observe the red and green LED lights on the Hall sensor by rotating the flywheel manually.

If either LED stays constantly on, the sensor may be damaged. A faulty Hall sensor can cause some cylinders not to fire and prevent the engine from accelerating properly.

4. Throttle Free Play

Check the throttle arm’s free play. Sometimes pushing the arm slightly against the carb improves fuel flow. This is especially important if the engine struggles when the throttle is opened quickly.

5. Cooling Awareness

The Cison V8 can shut down at higher temperatures (around 70°C) if fuel flow isn’t consistent. Always observe engine temperature and allow it to cool if repeated starts fail. Overheating can exacerbate fuel backflow and idling issues.

6. Patience & Observation

Every engine behaves slightly differently due to manufacturing variances. Take time to observe the engine, adjust fuel settings slowly, and check all connections. This is normal for precision-scale engines like the Cison V8.

3. Lubrication & Maintenance

Question: How should I install the six-blade fan on my CISON V8?

Problem:
“I’m hoping someone can help me with this six-blade fan. If you have purchased one and can provide a good clear photo of it I would be interested in knowing which direction the blades are pitched. The five-blade fan I have pictured is pushing the air into the radiator as opposed to pulling cool air through the radiator past the engine. I would also like to know the diameter of the six-blade fan to see if it would fit in the fan shroud I have pictured.”

Answer / Solution:

If you are standing in front of the engine, the engine turns clockwise, and the six-blade fan is pulling air towards the engine.

The direction of rotation and the blade angle determine airflow. Even if mounted differently, the air will always move in the same direction; mounting it backward only reduces efficiency.

Correct orientation: the concave side of the fan blades should face the airflow, convex side against it.

Note: The belt does not influence airflow in this engine—it’s a gear drive with an idler, so airflow direction is determined by engine rotation.

If the fan pushes air the wrong way, you are effectively running the engine backwards, which should be avoided.

4. Tools

Coming soon – Recommended tools for assembly, maintenance, and adjustments.

5. Upgrades & Modifications

Coming soon – Guidance on Hall Sensor upgrades, rotor improvements, and other performance enhancements.

6. Troubleshooting

Question :The engine is running too rich, spraying raw fuel from the exhaust, due to carburetor mis-adjustment and incomplete firing of cylinders.

Problem :

Would someone be able to describe in detail the Cison V8 carb? Mine runs so rich it is puking raw gas out the exhaust. No matter what I do to tune it, it does not seem to help. I have read the instructions for tuning the carb, but I guess I do not understand what they wrote. Is the main jet the adjustment on the opposite side of the throttle lever? What is the screw going through the throttle control? I guess I need information on how to get it back to factory settings. Thanks.

Answer / Solution:


The Cison V8 carburetor has two main adjustments: a low-speed (idle) needle and a high-speed needle.

Low-speed needle: Controls the minimum throttle opening and idle fuel flow. Turning it changes how much fuel is pulled into the engine at low RPMs.

Throttle screw: Limits how far the throttle closes, indirectly controlling airflow and fuel suction.

To correct a too-rich mixture:

Gradually adjust the low-speed needle to reduce excess fuel.

Adjust the throttle screw to allow proper airflow while limiting fuel suction.

Make small incremental changes and test the engine after each adjustment.

Safety Note: Only adjust in small steps. Incorrect settings can flood the engine or cause it to run improperly—effectively turning your engine into an expensive non-working model. Always monitor engine response carefully and ensure all cylinders are firing correctly.


Question: CISON V8 only fires on half the cylinders, likely due to a hall sensor issue or incorrect distributor/rotor timing.

Problem:
Ok, why does my CISON V8 only fire on cylinders 1, 7, 2, 6 and not fire 3, 4, 5, 8? I have changed spark plugs, changed wires, taken the distributor cap off and cleaned it thoroughly. Moved a non-firing plug and wire to one of the locations that does fire and it fires. I have removed and checked each individual plug. This seems strange to me that only 1/2 are creating spark.

Answer / Solution:

Check the hall sensor:

New versions include a circuit protection module. If both the red and green LED lights flash alternately as the flywheel rotates (only one light on at a time), the hall sensor is working properly.

If a light stays on constantly, the hall sensor needs replacement.

Verify distributor/rotor timing:

Use the manual as a reference. Rotate the flywheel through each stroke on cylinder #1. At the moment of spark, the rotor tab with the blue mark should be facing forward.

If the rotor is 180° off at the compression stroke for cylinder #1, the distributor is misaligned—correct it to ensure all cylinders fire properly.

CDI box check:

If the CDI is only sparking for one sensor initially, it may appear to be a hall sensor issue. Confirm all wiring and sensor function before replacing parts.

Recommendation:

Contact Stirlingkit to order a replacement hall sensor with circuit protection if needed.

Rotate the flywheel by hand with the ignition on to visually confirm each LED flashes in sequence, ensuring proper firing of all cylinders.


Problem:

I really wish there were actual instructions for the plug wiring. I think that the idea was that you use the little silicone sleaves to hold the wire to the tiny bolts, which then get inserted in the boots and used as contacts. I did try that. It worked for about a minute, but the contact to the terminals/plugs was lost from vibration. I went back to just the wire, no bolts, but this time I coiled the ends to make sure no contact would be lost from the wire getting frayed or pushed to the side. On the distributer side, I also threw a little solder to keep the ends intact 100%. (Didn't put any on plug side because I figured it could melt). So far this works well.
Really though, I'd just like to see proper plug wiring. That would be high on my list of improvements. Are there any other engine models out there that have wiring we can get that would work better?

Answer:
We totally understand your frustration—those micro-connectors can be tricky on the first build. Here’s what many experienced builders (and our in-house testers) do to get a solid, vibration-proof connection:

Coil the wire ends tightly so they make firm contact inside the boot—this reduces the chance of the wire shifting or fraying.

Add a touch of solder on the distributor side only. This keeps the wire from unraveling, but avoids heat issues on the plug side.

Use a small piece of heat-shrink tubing to secure the resistor or the wire tip—this adds grip and prevents vibration-related disconnects.

Some advanced builders even make small clip-style terminals using 1/8" brass tubing with a slit, which works very much like a real spark-plug connector.

If anything feels off, or if any plug boots or wires arrived loose or damaged during shipping, just let us know—Stirlingkit can send replacement parts to you for free. We want your V8 running smoothly and reliably, and we’re here to help anytime.

Question:

Does anyone have any tips on v8 flathead dual carburetor adjustment....
And can you please explain what knob/screw is what...
Got timing good but cannot figure out adjustment..
Thanks

Answer:

I'd like to share with Cison engine owners what I've done to make my Cison carburetor work properly with my fg-vt157 15.7cc engine.
I believe that Cison is using the same carburetor for the v2, l4 and both v8 engines.
The only difference that I can see is that the ohv V8 has a different throttle body but internally probably the same.
I believe this carburetor has one flaw and is the reason why the Cison carburetors are so sensitive to adjust.
Just like others I was having a hard time tuning or getting a stable low idle so I also tried a few different carburetors and even tried adding a pressure line to pressurize the fuel tank from the exhaust.
None of these attempts worked the way I was hoping so I busted out my gauges and took a closer look the original Cison carburetor after measuring every part of the carburetor I found that the skinny o-ring on the throttle barrel was not providing enough squash between carburetor body and throttle barrel not providing a good seal.
Also I found that the throttle barrel can move up and down approx 1/64" which definitely doesn't help.
My fix was to add a slightly larger diameter o-ring for the throttle barrel.
I then took the original throttle barrel o-ring and used it to take up the 1/64" up/down play.
Now the carburetor is easy to tune provides a stable idle also sounds like the engine reaches a higher rpm and super awesome throttle response.
I believe this will work on all the new Cison
Carburetors
This Carburetor works very well, try this with your Cison carburetor.
Please let me know if this helps you out.
Thank you


Question:

Where can I get the M3 fittings to add rocker arm oil lines to the Cison V8 OHV heads, and is it recommended to install them?

Answer (summarized from multiple contributors):

Installation caution:

Not recommended to install as-is, because the valves have no oil seals, and too much oil could enter the combustion chamber.

If you do install, it’s important to restrict the oil flow to the top end so the crankshaft’s spray bar still lubricates properly.

Fittings source:

M3 fittings are not widely available commercially, but similar ones can be sourced:

Brass T fittings can also be used to modify lines.

Practical solution:

Add a restrictor or modify a fitting (e.g., solder the nipple and drill a very small hole) to limit oil to the rocker arms.

This keeps the rockers lightly lubricated without flooding, minimizing oil in the combustion chamber.

Some builders also use a small lead weight in the line to restrict flow.

Expect minor smoke at startup or throttle blips; plugs should not show signs of burning oil if flow is controlled.

Question:

The belt on my Cison V8 won’t stay on. I’ve tried adjusting the alternator angle, but it keeps coming off at the water pump. Any tips?

Answer:

If you notice the belt slipping or coming off during operation, don’t worry—this is usually related to pulley alignment rather than a defect. Here’s how to ensure smooth belt operation:

Check Pulley Alignment:

Make sure all pulleys are installed parallel and seated correctly.

Loosen set screws on the water pump and oil pump pulleys, then rotate the engine by hand a few times so the pulleys can self-align.

Inspect Pulley Bearings:

Confirm that all pulleys spin freely without wobble. Any movement in the bearing will cause the belt to slip.

Adjust Slotted Pulleys:

Some idler pulleys have slotted mounting brackets. Slightly adjust their position up or down to improve belt tracking.

Check Alternator Mounting:

The alternator mount can tilt slightly at the bottom. Ensure it is stable and aligned with the belt path to avoid unwanted tension or misalignment.

Guide Lips & Custom Adjustments:

The stock guide lip may be lower than ideal. For extra security, some builders add a thin washer or small guide on the crank pulley to help keep the belt centered.

Belt Type & Tension:

Use the correct cog belt included with your kit. Proper tension and alignment are more important than forcing the belt onto the pulleys.

Pro Tip: Patience is key. Take your time checking each pulley and adjusting positions carefully. Once everything is aligned and secured, your belt should run smoothly, ensuring reliable operation and longevity of your Cison V8.


Final Note

These tips are based on real experiences from CISON V8 owners. By following these steps, you’ll save time, reduce frustration, and enjoy your engine to the fullest.

💡 Pro Tip:

1. We truly want to thank every Cison V8 owner who has shared their experiences, tips, and advice—your stories and insights are what make this community so special. If you have any suggestions, clever tricks, or helpful tips, we’d be honored to see them! You can send your contributions—whether text, photos, or videos—to service@stirlingkit.com . Selected submissions may receive a gift card worth $50–$200 as a small way of saying thank you. Your support and generosity help fellow builders enjoy their Cison V8 even more, and we deeply appreciate it.

2. Bookmark this page—it will grow over time with new user insights and practical solutions, creating a complete resource for all CISON V8 enthusiasts.

Update time: Dec 11, 2025

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The World’s First Mini V8 Bike You Can Ride – Powered by Cison V8! Insane! | Stirlingkit

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Notice: Ensure You're Buying Authentic Stirlingkit Engines | Stirlingkit


4 Reasons Why I Love Cison V8 OHV Engine Model Kits by Joseph | Stirlingkit

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