HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
yzf_rider400

loss of power - compression problem?

7 posts in this topic

was riding today and after a couple of hours I suddenly lost a noticeable amount of power and the bike would sort of sputter (the power would come on and off in quick succession). I looked at my header pipe once I got back to the truck and noticed the retaining socket cap bolt had fallen out.

Do you think this would decrease the seal enough to lose compression and create the problem I'm describing. I should mention that I wasn't using a header gasket (dumb ass) -- but I've never had the problem before.

Other possibilities I could think of would be the decompression lever (the one mounted to the engine) got stuck open somehow? Or maybe I've got a dirty carb (although my dad and I cleaned it not too long ago).

Your thoughts and suggestions are appreciated! :thumbsup:

Share this post


Link to post
Share on other sites

unlikely that the loose bolt would cause a noticable drop in power. Would make it backfire on deceleration though.

If the decomp system was activated the engine would instantly stall. I'd start at the carb, then do a leakdown test and check the ignition system.

Share this post


Link to post
Share on other sites

thanks guys, I'm going to check it out today. You think I might have a fouled plug? I'll check the air filter, but I did just clean it two rides ago.

Share this post


Link to post
Share on other sites

Well, that's not really important how many rides it's been since it's been cleaned. I have clogged my air filter with one 10 minute ride in Glamis, then other days have ridden all weekend in Colorado with no problems... :thumbsup:

Share this post


Link to post
Share on other sites

butta... You may be right. I'm going to clean it again before I go ride, although it doesn't look very dirty. I pulled the fuel tank and checked my spark plug (looks fine) I think I may not have had my spark plug cap fully seated though (would this cause the problem). I reinstalled everything and she starts up and sounds good now. hmmm... hopefully she'll keep her [@#$%&*!] together now. :thumbsup:

Share this post


Link to post
Share on other sites

Hopefully that was it! Most of the times I've been concerned about a lack of performance or hear a different sound the solution is an easy and quick fix (generally caused by something I did - or didn't do). These bikes are great! Incredibly reliable for what we put them through.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0