General 2 stroke question

[bdh825]

I know when riding a 2 stroke mx bike that they are designed to be ridden hard and pretty much open on the gas. (seems at least on mine when moping around it fouls plugs or causes some kind of engine bog)

My question is, is that when going down a hill, rolling totally off the throttle, and keeping the bike in gear without pulling the clutch (usually first) (pretty much letting the bike hold you back).. is this something not good to do on a 2 stroke mx bike, or should it not be a problem at all?

 

[OKKX'er]

All the oil that lubes the piston rings and rod bearing comes into the combustion chamber with the gas. If your motor is turning with hardly any gas going into the area of moving parts, then there is very little lubrication to these parts.

 

[showtime586]

I know when riding a 2 stroke mx bike that they are designed to be ridden hard and pretty much open on the gas. (seems at least on mine when moping around it fouls plugs or causes some kind of engine bog)

My question is, is that when going down a hill, rolling totally off the throttle, and keeping the bike in gear without pulling the clutch (usually first) (pretty much letting the bike hold you back).. is this something not good to do on a 2 stroke mx bike, or should it not be a problem at all?

What okkxer said is true, unfortunately most of us ride down steep hills in the manner that you describe above.

 

[darringer]

Try using the front brake for speed control on steep, long downhills. Pull in the clutch and blip the throttle occasionally to keep the bike from loading up. This technique has always served me well. Coasting downhill for extended lengths without pulling in the clutch can cause a piston seizure from higher temps and lack of oil.

 

[steve125]

If you have an idle speed set, you can go down hill all day long and will have no issues.

 

[bikepilot]

There is plenty of lube in the crankcase for reasonably long downhills. I have allways ustilized what little engine braking my 2-strokes have with no ill affects. If you going down a huge mountain, you should probably give it a little gas from time to time.

On your first point, the issue with 2-strokes fouling or loading up is not so much a design issue as so many people assume, but simply poor jetting. Get the jetting right and a 2-stroke MX bike can idle and putt around at low rpm all day without loading up or fouling a plug. Case in point: my wife has a KX100, she decided she needed to work on her technical skills with tight turns, log crossings etc, so we set up a little obsticle course in my back yard (1/3rd acer) she rode around for about 2 hours without every getting it on the pipe or going over about 15mph. She also got quite good at going over logs and threading her way though tight trees etc. BTW my KX125 and CR250 are equally happy putting around at low rpm as they are flying around an outdoor MX track at high rpm/engine load:)

good luck

 

[bdh825]

Thanks for the info, helps me out a lot.