over-revved; stumbles & missing above 3500rpm

[Philip Campbell]

The front brake of my KLR has an odd feel. When the brake is applied and then released, the lever does not return to its normal position. I have to pull it out an extra inch or so to get it to the position it is usually in when not being applied. I am unable to tell while riding if the brake is still partly engaged as this happens, though I do not feel any drag on the bike. The brake also seems to work all right-- it will lock the front wheel if required. Has anybody got any advice about diagnosing or fixing this? Phil [Non-text portions of this message have been removed]

[John thomas]

Wow one time and you have trouble? Am I ever lucky! I over rev on a consistent daily basis and no problems yet! (knock on wood) How many miles do you have on her? Have you done the doohicky? What spring did you use on the doohicky? How tight were your valves? What do you call over reving? 500rpm over redline? - 3000 rpm over rl? What year model? I have a 1990 Tengai. I don't beleive that I have ever exceded 1000-1200 rpm over red line and verry breif 2-3 seconds. It is hard to keep that front wheel up without doing it. Thomas Forest Park Ga. "Old Geezer club member 39.11" 90 Tengai 21,000 miles ----- Original Message ---- From: Jud Jones To: DSN_KLR650@yahoogroups.com Sent: Tuesday, May 6, 2008 1:14:02 AM Subject: [DSN_KLR650] Re: Over-revved; stumbles & missing above 3500rpm

--- In DSN_KLR650@yahoogro ups.com, "E.L. Green" wrote: > > --- In DSN_KLR650@yahoogro ups.com, Peter Meilstrup > wrote: > > So yesterday I pulled out to pass someone and screwed up a downshift, > > going into 3rd when I thought I was going into 4th. The engine > > overrevved and immediately lost power. > > Valve float from overdriving the valve train, maybe slung your rings? > > > I pulled the spark > > plug and it looked like usual (i have no idea how to read plugs.) > > Can't read plugs with modern gas, it's always a light gray-tan. > > > > missed a fuse somewhere, I tried the starter again and it fired up. > > However it would stumble and miss above 3500 rpm and would pop on > > deceleration. > > Maybe when the valve train was being overdriven your cam chain jumped > time? > > > > What do you think is going wrong? I have a suspicion but I wanted to > > get some independent ideas from the list before I start taking engine > > covers off. > > Okay, first thing I'd do would be to take the cam cover off and see if > the valve train jumped time, and check the valve clearances while > you're at it. If that all seems okay, next thing I would try would be > a leakdown test. That should tell you whether you managed to burn some > valves while they were floating off their seats during the overrev -- > if air starts coming out your exhaust pipe or carb horn, ya got a > problem, Houston -- you'll need a head job for sure. If instead air > starts hissing out of the crankcase because your rings aren't sealing, > again, ya got a problem. > > Chances are it's just the timing chain jumped time, which can be > easily solved by setting the engine at TDC then lining up the marks on > the timing chain (you'll need to loosen the cam caps and take the top > timing chain cover off and take the cam tensioner off to re-time it, > but we're not talking major surgery). If it's more than that... > (shrug). We'll see, hmm? > If it jumped time, you may also find you have bent some valves. ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ [Non-text portions of this message have been removed]