Braking Using Decompression Lever

Anyone here ever had a problem doing this??? Have heard it can do valve damage.

I remember the vintage 2 smokers using the compression release to help them slow down, but they had no brakes to begin with. The Honda system lifts the exhaust valve and that may get in the way of things but I doubt it. I've used the compression release to help a rolling bike turn the motor over to get it started and that didn't hurt it. I'm just having a hard time figuring why you need to slow an XR down with the compression release. How about the kill button?

I've used it extensivly in the past for limited traction surfaces, similar to the 2 stroke. It provides slightly more braking than just rolling off the throttle allowing you more control. I've been told by quite a few people on this web that it is a big no no and that it could wreck the engine/valves. Don't know if the kill button causes the same effect but I doubt it.

The kill button does nothing to harm your bike, it just stops the circulation of electricity through the coil resulting in shut down. The compression release lifts an exhaust valve out of normal sequence which could result in major damage. Is it going to happen 100% of the time? No, but repeating this action is asking for eventual failure. The brakes on XRs work great if you balance the front and rear along with lightly feathering them. I ride snotty clay downhills all of the time and never have a problem. If you start to slide, let off the brakes and pull in the clutch. You will gain a little speed doing this, but nothing that will cause you to lose control. The secret to riding the wet slick stuff is to do nothing sudden.


hey dutch, what is a budsboy stabilizer?

Ryan, thanks for the input. I've been trail riding for 30 somethin years now on and off. I was really more interested in the EXACT description of the PROBLEM this causes with the engine, not that it would simply DESTROY it. I think I have figured it out myself, since not too many people seem to know how it REALLY works (yeah I know...who cares). I tryed to describe it in detail, at least how I THINK it works, in the XR400 discussion group. Having never had the head off of ANY of my bikes though, it is just a guess. Please correct me though if you think I'm wrong.


I am sorry I did not answer your question in the exact fashion you demanded. I must have missed the exact specifications of your post which was pretty vague. To answer your question bluntly, "No I have not had this problem with my bike." It may also be helpful for you to know that I do not partake in this act.

An old mechanic, with over 30 years of experience, told me to stay away from the decomp lever while the engine is running because pulling it at RPM could cause damage in the head. True, I may not understand exactly how it works, but I do trust a guy with so many years of experience. Personally I do not (and will not) choose to pull in the decomp lever while the engine is running, though my knee does bump it on occasion out on the trail. You may choose to pull in your decomp lever on your bike, but I do not want to be the one that told you it was OK. I know this is not the answer you want to hear, I believe you asked this question with a predetermined answer in mind.

If my post did not provide you with the info you need then just disregard it. You need to realize that not all of us have the knowledge of the greats like Dwight and Gary. I will offer you what I know, take it or leave it, but don't be an ass about it.

Ouch...lighten up dude! I didn't demand anything. If you don't know how it works or don't want to bother to find out how, thats cool with me. It's just not my style to believe everything I read or hear. I don't care if it's from the freggin president! I just question EVERYTHING in life! When someone says "don't do that" I just wonder what the reason is...THATS ALL. Some people never question anyone or anything. Thats what is so wrong with this screwed up country of ours. If I hurt your feelings than I am sorry...that is not what I intended to do.

Hi. I honestly have no idea why you would even try something like that! The 650R engine provides more than enough compression braking just by letting off the gas. And also the brakes are very good! Never pull in the compression release to slow the bike. It's fine to use the lever for restarting the bike if it dies while you're rolling, but don't pull it in while it's running! That's asking for a valve to hit the piston. Read the manual! I'm sure the people who designed the bike probably know how that lever is supposed to be operated. Good Lord!!

Don't have a manual. Valve won't hit the piston. I'll let you know how long it takes for me to blow up my motor. Heck, someones gotta do it. I figure if Bush can do somethin so stupid, so can I. :)

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