Customer Reviews

Based on 2011 reviews
Cison Output Shaft FL4 / L4 OHV

Great accessory for the L4 & FL4 engines! Allows a 6mm shaft to be added to the flywheel for power take off. Fits perfectly and includes the bolts necessary to install.
Thanks Stirlingkit!!


This was a great build that got me warmed up before starting the dragon model.

The difficulty is there when you get towards the body as some of the steps are challenging to complete by yourself.

Overall this piece was not disappointing

Otto / SEMTO Motor Muffler

Works & fits the Otto / Semto perfectly. Nice design and directs nitro exhaust out to the side of the engine. Thanks Stirlingkit!

R29 Replacement Spark Plug

I bought a couple replacement spark plugs for my R29 engine. They arrived fast and include a plug boot for each one. They are sold each. Thanks Stirlingkit!

Cison Performance FL4 Intake Manifold

Can’t wait to try it out! This is the high performance Cison FL4 intake manifold. Extremely well made, and a beautiful part.
Thank you Cison & Stirlingkit!!

Musa CDI Ignitor

Arrived perfectly and works great! Comes with 2 different spark plug boots, one black and one clear to see the spark! Extremely well made… Musa makes some awesome engines and components.
Thank you Stirlingkit!

Cison FL4 / L4-175 CDI Module

I bought the CDI module for my FL4-175 because this newest version does not use an external ground wire. Works perfectly and arrived fast in a matter of days from Stirlingkit! Thanks as always Stirlingkit!!


I received the wrong bearing. The bearing received was in wrong packaging and Stirling will not reply as to shipping correct bearing as ordered. Picture shows bearing is not for the camshaft #6 as ordered.

awesome knuckle head mini

I am a Harley builder and love this motor.

Another INCREDIBLE Cison Engine!

Cison Engines has done it again with their L4–175 17.5cc miniature four stroke, OHV four-cylinder engine.

The L4-175 engine is my fourth Cison engine I have bought from Stirlingkit, and what an amazing kit!
Just like the FL4 flathead kit, the L4 OHV went together flawlessly, was fun to build with easy to follow build instructions.

Parts quality, fit, finish, and layout is awesome. It’s easy to see Stirlingkit and Cison are proud of the L4, just by the kit’s presentation.

My kit arrived quickly, 4 days after it was shipped from Stirlingkit’s warehouse.
Packaging has always been perfect and arrives safely, just as each and every one of my orders have arrived from Stirlingkit.
Assembly instructions are in an easy to follow QR code based illustrated manual, in numbered parts & parts location format. Once I completed the kit, I installed the components of the starting set (Hall sensor, CDI, coolant lines & radiator) and had immediate success starting & running my engine. Performance is incredible, and tuning is very straightforward.
The Cison L4-175 definitely runs phenomenally.

Huge applause to Stirlingkit & Cison for producing another awesome engine!!

Love My New Engine

I run my engine on a 50:1 two cycle mix. Stihl leaf blower mix. I did have a problem with the clear plastic tube gasoline tank. After putting gas in the tank I noticed a small crack. The next day the plastic tank was full of cracks. It seems the gasoline was reacting with the plastic. I ordered a new piece of polycarbonate tubing 1-1/4 x 1-1/8. It fit fine and made a good seal after careful cutting. The new tube holds up with gasoline. I notice to be careful not to choke while starting more than one turn of the crank or sparkplug will foul. The seal washer on the plug is poor quality. I needed to place a small amount of RTV sealant on the washer to make a good seal. I test the seal with leak soap to ensure a good seal. I can now start the engine with less than one turn. I feel like a kid with a new toy!

Interesting little engine

The one I received doesn't look like the one pictured and had a few issues with my Stirling engine. Customer Service Rep was friendly and helpful.

Nice little engine

I just finished my l200ac. Went together easy. Runs great. I did have to modify the rocker arms, there was no clearance and the valves weren't closing. I just polished the contact surfaces on the rockers with a fine file then 1200 grit sandpaper until I had a little clearance so the valves could seat. Overall a great buy,

Water pump for Holt engine

The water pump works perfectly,
I have rebuilt it a bit for my purpose and equipped it with a

Enjomor Whippet

The engine is perfectly built and finished,
unfortunately I can not test it yet because the defective CDI from Stirlingkit has not yet been delivered.
But here already a picture.

Toyan Engine

Toyan engine after reassembly and adjustment.
runs engine with gasoline very well.

Toyan FS 100AT as gasoline engine

Toyan FS 100AT after assembly and adjustment
engine runs with withe gas.


I wanted to own a model engine for quite some time now, but I either couldn't afford it or wasn't satisfied with what I saw and COULD HEAR in videos.
So the VT9 is my first one and I love it! Yes, it's all about the sound, the smell and the vibration!
It was quite challenging to find the right settings for a slow idle speed. But I think an engine lover will enjoy that. What surprised me though was that it started on the first try after unboxing.

R29 Knucklehead 😁

What an outstanding miniature engine!

I ordered my R29 Knucklehead immediately after it went on sale, and was thrilled when I got my notification that it had shipped from Stirlingkit!

This is my 5th engine that I have bought from Stirlingkit, and always look forward to what they will be releasing next.
My R29 arrived three days after it left Stirlingkit‘s warehouse, using DHL express shipping.
It arrived safely and in perfect condition, as all my engines and parts have arrived.
Stirlingkit‘s packaging method is outstanding, and the special presentation box they had made for the Knucklehead, really stands out and was totally worth waiting for. It’s a beautiful sturdy black box, with a picture of the engine embossed on the top section with the new Retrol brand logo.

The instruction manual that comes with the R29 Knucklehead contains a lot of engine information; such as specifications, setup & how to operate the engine.
The engine is completely ready to run. Install 3 AA batteries and add fuel.
For fuel, I chose ethanol free w’ added 2 stroke oil as recommended. I wanted to try starting my engine directly out of the box, using the preset carburetor setting.

My R29 started immediately using the included drill adapter, and idled perfectly stable.

This engine sounds incredible!
It has a very crisp exhaust note, and runs all through the RPM range beautifully. Although the fuel tank is small, it will run a surprisingly long time off a single tank of fuel.

The details of the R29 engine are spectacular. Retrol has put a lot of effort into even the smallest details, such as the tiny hardware, simulated oil pump & top-end oiler line, and beautiful CNC made jugs & heads.

I have now ran around 10 full tanks of fuel through my R29, and the engine continues to run better and better with each tank.

What I was most impressed with was the ease of starting. No need to use the drill starter after the engine gets a little time on it, one or two flips of the flywheel is all it takes to bring the engine to life now.

Stirlingkit has released yet another miniature scale engine to be extremely proud of, and the R29 will be another engine loved by their customers. Huge applause Stirlingkit 💕👏

A nr 200 push to the limit

This test subject is promising despite its small carburettor flaws easy to fix the metering valve main needle jet valve was not delivering enough fuel at high revs after shortening and adjusting the needle taper engine runs better To really see the ability to tow a large vehicle I chose a 1\8 hpi savage x monster truck the excessive weight of such a truck should be enough to test the capacity of this engine After a few adjustments, a quick little test, I must say that the engine has good power at low revs and tows the truck without any problems with the soft clutch springs, which were used with the red aluminum pads, and it does not seem to slip. YouTube video placeholder
Little engine

The quality is amazing, the material is heavy and shiny. No manual instructions 🙄, but taking your time and watching the videos, try and error finally got it 👍

Enjomor Hit & Miss Engine

Good Day
I would like to say that I am very impressed by this little engine, she fired right up straight out of the box.
I have dressed her up a bit including a base which houses the electronics along with some extra weight so she does not move about while running.
Other mods include a softer governor spring, and the use of one 18650 cell along with a switch for ignition.
Thanks Again for a very scale excellent running model engine
Take Care

Wasp of Fun

I have built many Stirling Kits, My wife enjoyed watching the process, so I purchased this one for her, she just loved building it and has now ordered many more to complete. The instructions were clear and easy to follow, we could not be more pleased with the results. The quality of the parts included are very good, she did not have any missing pieces and the kit included a few tools

CISON FL4-175 Oil Filter

This filter fits the FL4-175 perfectly.
Nicely made construction, great finish & quality! Really adds scale detail to the FL4-175. Thanks Cison & Stirlingkit! Can’t wait to see what other options are developed for the FL4 flathead in the future 😁