2-Stroke Engine Braking

[Enginedude101]

why would you want to do this, it's not good for the engine in my opinion.
you'd be allowing the piston rings to scrape the cylinder walls with no oil, and the bearings to possibly run dry.
since the engine would not be running, there would be fresh no gas/oil entering the crankcase.
I understand that there would be residual oil on the rings and bearings, but it can't be all that much.
I would think that doing this a lot over time would just prematurley wear out the rings and bearings due to short times of no oil.
I wouldn't do it.

Vacuum is still created by the closing thottle valve. Fuel discharge nozzle is located after the throttle valve. The vacuum created by the engine reciprocating would still pull fuel into the engine to allow lubrication. Even if he turned ignition off, the fuel and oil would still be pulled to lubricate all engine components. Only downside is possibly fowling the plug. The engine will be just fine during engine braking.

 

[DAMIEN1307]

Vacuum is still created by the closing thottle valve. Fuel discharge nozzle is located after the throttle valve. The vacuum created by the engine reciprocating would still pull fuel into the engine to allow lubrication. Even if he turned ignition off, the fuel and oil would still be pulled to lubricate all engine components. Only downside is possibly fowling the plug. The engine will be just fine during engine braking.

Welcome to the forums...Hoping your not expecting a reply from @motorpsycho anytime soon...lol...If you notice the date code on his post, you will see he wrote it 10 years ago...He was Last seen in the forums Apr 30, 2015...6 years ago...i'm afraid he's long gone...lol...DAMIEN

 

[Karl Snarl]

you get stator coil damage from grounding the coil out. if its a quality coil this shouldn't happen, but kit coils will burn up. as for the engine, WOT, with no spark is actually used by desert racers on down hills to cool the engine in 120 degree temps. won't hurt at all. now with it running, its a gamble. may not cause any damage, may accelerate wear. up to the rider to use engine braking while engine is running, or not to.

 

[Chop-chop]

Its NOT recommended to compression-brake in a 2-stroke setup, this is because engine lubrication is delivered along with the fuel and you're essentially applying stress to the engine in the form of compression braking minus the lubrication factor due to the close throttle.

 

[loquin]

hi folks just wondering what possible damage can be caused by using the engine as a brake (engine braking ) by turning ignition off and clutch out.

all opinions appreciated

Well, with no throttle, you get no lubrication ...

 

[LewieBike]

Anyone who's owned a two stroke dirt bike understands that a two stroke has way less engine braking than a four-stroke.

That why bikes in the 1970's had "jake brakes", decompressers that introduced a bit of engine braking at the expense of engine longevity, especially when used in dusty conditions.

Oil Injection was introduced in 2 cycle motorbikes because engines would seize if left idling when descending long downhills with the engine throttle closed. The injection systems always delivered a metered amount of lubrication sufficient to keep the piston and rings from scuffing up the cylinder walls, because otherwise an idling premix engine only provides a minuscule amount of lube when driven faster by gravity.

Using a bit of partial choke could help, but you may foul your plug.

 

[Chainlube]

Anyone who's owned a two stroke dirt bike understands that a two stroke has way less engine braking than a four-stroke.

That why bikes in the 1970's had "jake brakes", decompressers that introduced a bit of engine braking at the expense of engine longevity, especially when used in dusty conditions.

Oil Injection was introduced in 2 cycle motorbikes because engines would seize if left idling when descending long downhills with the engine throttle closed. The injection systems always delivered a metered amount of lubrication sufficient to keep the piston and rings from scuffing up the cylinder walls, because otherwise an idling premix engine only provides a minuscule amount of lube when driven faster by gravity.

Using a bit of partial choke could help, but you may foul your plug.

If the engine is in tune, that will go away as soon as you hit the throttle again.

 

[Frogslayer]

When I "engine brake" my China doll, I hold the kill switch and part throttle. When I rode 2 stroke bikes a lot back in the day, I down shifted all the time, like every time I slowed down. I had one oil injected and one was deleted of the two I mainly rode. Never scorched either one.

 

[LewieBike]

I never felt the need to delete something that worked as well as the PosiForce and CCI oil injection systems. You were told by the Suzuki shop to never remove the injection system on the CCI oil injection.

 

[Frogslayer]

Suzuki oil injecting systems were ultra reliable. Yamaha injecting systems were known for failing.