Engine braking question

Dannt D

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I have 125 miles on my new 07 NE5. Sometimes I turn the 'run / stop' switch to stop when I need to slow down instead of riding the brakes. I also figured out that if I hold the compressino release and give about 1/2 throttle it pops real loud and blows flames out the pipe. Will this hurt anything other than my relationship with the neighbors? Could this poping cause oil leaks in the engine?
 

WZ507

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Engine braking

If you are holding the throttle half open with the ignition switch off, the carb is feeding gas to the engine at the same rate it would if the ignition switch were on, which causes the cylinder to load up with gas, which in turn washes the cylinder bore free of oil, which in turn is a very bad thing as it wears the rings and bore excessively. If the compression release is pulled it's not quite as bad, but still a practice that I'd have difficulty condoning. My advice would be don't do that any more if you like your engine.
 
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RdKryton

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WZ507 Covered it pretty well. Throwing the kill switch off while riding is not good even if your not giving it any fuel. You still have raw fuel going into the cylinder that will cause premature wear by washing the oil from the rings and cylinder. Also doing the flame thing with the compression release will cause you to blow your head gasket. It might be fun to watch but in the long run but you are destroying your investment. I know the brakes on these Whizzers are a weak spot but those two things your are doing will cause you problems and cost you money.

Jim
 
R

ren

Guest
I have a 2007 NE5, and this question might fit here. Is it ok to hold the compression release to push the bike forward a short distance with the engine not running. If not then one has to pick up the back end of the bike to move it forward because the back wheel will not roll but slide.

Thanks
 
R

ren

Guest
Thanks Quenton, it's good to know I haven't been doing harm. By the way I'm waiting for it tool cool off a little before I make the mods I purchased from you. Will post results when done.

Thanks
 
S

smitty

Guest
I don't see how opening the compression release with the engine running (and a little throttle) will blow the head gasket. There will be less pressure in the cylinder with the exhaust valve open, than when the engine is running (especially accelerating). I agree about the fuel washing the cylinder walls promoting wear. The popping and flames would be raw (burning?) fuel entering the pipe and muffler.

On restarting my bike after a short stop, it will often 'report' (pop) just as I release the compression release. I figure it's the unburned fuel that passes through the engine into the pipe and muffler, after the ignition is switched off. Sometimes it's loud enough to make pedestrians jump.
 

Dannt D

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I understand washing the oil off cyilnder walls when the engine is cold. Starter fluid can do this in a bad way. I would think when the engine is at opperating temp the vaporived gas would not condense on the cylinder walls and would not dilute the oil. With the throttle being closed there would not be much fuel going through anyway. I am talking about doint this at speeds of over 10 MPH. The engine is still oiling itself as it turns through. I may be wrong here so please feel free to post a follow up. Thanks, Danny
 
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