Vamrion F2 Twin Cylinder Gasoline Engine
Assembly Guide and First Start Tips
First Impressions
After receiving my Vamrion F2 twin cylinder gasoline engine, I was pleased to find that everything arrived in excellent condition. The packaging protected the contents well and there was no shipping damage.
I ordered both the engine and the accessory pack. Everything required to assemble and run the engine was included:
* Engine mounting base
* CDI ignition system
* Spark plugs
* Radiator
* Cooling fan
* Silicone coolant hoses
* Fuel tank
* Water tank
* 11.1 V LiPo battery
* LiPo charger
* Allen keys
* Spark plug wrench
No parts were missing and everything was securely packed.
The machining quality was excellent. Every component was cleanly finished with no burrs, scratches or damaged parts. The engine immediately gave the impression of being a quality product.
The instruction manual is comprehensive and well organised. The only improvement I would suggest is increasing the contrast of the part numbers and screw labels, as they can be difficult to read under lower lighting. I strongly recommend following both the official assembly video and the printed manual together. They complement each other very well.
Engine Assembly
Lubrication
Throughout the entire assembly I used Motul 710 Fully Synthetic 2T Oil.
Every moving component received generous lubrication before installation, including:
* Crankshaft bearings
* Connecting rods
* Wrist pins
* Pistons
* Cylinder walls
* All internal rotating parts
Before moving on to the next assembly step I always rotated the crankshaft by hand to confirm that everything moved smoothly without binding.
For the camshaft lobes and rocker arm contact surfaces I used Yamaha Molybdenum Grease, which provides excellent protection during the initial startup before normal lubrication becomes established.
Gasket Sealing
Although the supplied gaskets fit well, I added a very thin film of Copper Gasket Maker to each gasket surface before installation.
This included:
* Crankcase
* Cylinder assemblies
* Cam covers
* Coolant inlet and outlet connections
Only a very small amount is needed.
Allow the sealant to cure for at least 12 hours before adding oil, coolant or fuel.
After completing the assembly and running three full tanks during break in, I found no evidence of either coolant or oil leaks.
Valve Clearance
The kit includes shims for valve lash adjustment.
My recommendation is to assemble the engine without installing any shims unless you confirm that adjustment is actually necessary.
Allow the engine to complete its break in period first, then check the valve clearances. If adjustment is required, install the appropriate shim afterwards.
In my engine I did not need to install any valve shims during assembly.
Hall Sensor
I installed a small washer behind the Hall sensor mounting screw.
This provides a stronger clamping force and helps prevent vibration from allowing the Hall sensor to move, which would alter the ignition timing.
I chose not to use thread locking compound because I wanted to experiment with ignition timing during testing.
Water Pump
Before final assembly, make sure the impeller rotates freely inside the housing without rubbing.
Correct any interference before the engine is completed.
Engine Mounting
Instead of mounting the engine directly to the aluminium base, I installed small rubber O rings under each mounting screw.
These act as simple vibration isolators, reducing vibration transferred to the base while also helping to reduce the chance of screws loosening during operation.
Radiator Modification
I modified the cooling fan arrangement slightly.
In the standard configuration, the fan pulls warm air from the engine through the radiator.
Instead, I mounted the fan on the front of the radiator so it pulls cool outside air through the radiator core.
To provide clearance between the coolant hoses and the timing belt, I rotated the L shaped mounting brackets outward before securing them.
This arrangement allows the radiator to receive cooler air while also directing some airflow over the engine itself.
Tightening Fasteners
Take care not to over tighten the screws.
The engine is manufactured from aluminium alloy, and excessive tightening can easily damage the threads.
Tighten each fastener only enough to compress the gasket and securely hold the component in place. If unsure, it is better to check them again after the first few heat cycles than risk damaging the threads.
Whenever possible, tighten covers gradually using a crisscross pattern.
Fuel Mixture
For all testing I used a 40:1 fuel to oil ratio using Motul 710 Fully Synthetic 2T Oil.
This combination worked very well throughout testing.
Pre First Start Checks
Before installing the spark plugs, add approximately two drops of Motul 710 into each cylinder through the spark plug hole.
Next, connect the spark plugs to the ignition leads and ground the metal body of each spark plug securely against the engine or the exhaust manifold.
Do not crank the engine with the ignition system disconnected from the spark plugs. Doing so can damage the CDI ignition module.
With the spark plugs grounded, operate the electric starter for several short bursts of one to two seconds.
This serves several purposes:
* Confirms both spark plugs are producing a healthy spark.
* Distributes fresh oil around the cylinders and piston rings.
* Allows the engine to begin freeing up before combustion.
* Pushes excess oil out through the crankcase breather.
I connected the crankcase breather hose to a small homemade catch can. I simply drilled a hole in a small plastic container lid and inserted the breather hose through it.
This collects the oil expelled during operation and keeps the work area clean.
Priming the Cooling System
The water pump does not self prime.
Before the first start, fill the coolant reservoir with the recommended coolant mixture.
Then disconnect the inlet hose and introduce coolant into the engine until coolant begins filling the pump.
I gently blew into the coolant tank opening to help push coolant through the system until the pump was completely primed.
Once coolant reaches the pump, it circulates normally.
Initial Ignition Timing
For the first start I positioned the Hall sensor approximately in the middle of its adjustment range.
This provides a good starting point before making any fine tuning adjustments later.
Engine Break In
The break in procedure is one of the most important parts of building this engine.
During the first runs, use the minimum throttle necessary to keep the engine running.
Avoid prolonged high RPM until the engine has completed its break in period.
I recommend using repeated heat cycles:
* Run the engine for 1 minute, then allow it to cool for 1 minute.
* Run for 2 minutes, then allow it to cool for 2 minutes.
* Run for another 2 minutes, then allow the engine to cool completely to room temperature.
Repeat this process several times.
These controlled heat cycles allow the piston rings, cylinders and other internal components to expand and contract gradually, helping them bed in correctly and reducing unnecessary wear during the early life of the engine.
Following this procedure produced a smooth running engine with no oil or coolant leaks after three complete fuel tanks.
