NEED backfired and died...

I thought I had already posted this, but when I went back and checked, it wasnt' there so...

I had my bike shipped from the states to Turkey. I have been riding it here, to and from work about 4 mi round trip. Today was the first time I really had the chance to take it out and run it hard.

I rode about 10 mi of easy dirt roads, then about 5 mi of highway, where I rung it out. Didn't run it near redline or anything, just sustained upper rpms. When I slowed to make a turn, the bike backfired (back through the exhaust) and died. I rolled to a stop, and did a quick overheating, or nothing obvious, so I tried to start it...nothing. I let it set about 5 minutes, and she finally started. I rode it home (about another mile or so) and it seemed to run just fine, and tried restarting it in my driveway...nothing. Then it backfired once, and started on the next kick. The manual decompression didn't seem to work correctly, so I checked the cable, for pinching, and see if it was working correctly, adn everything seems to be in order.

Any ideas on what might be the problem? I'm not taking it anywhere very far from home, until I figure out what it's doing...


A GOOD backfire can mess up a spark plug. Replacing it is where I'd start...and its a cheap way to attempt a rememdy. When you take the old one out, see if the jetting looks right. Its possible that you may fix the stalling with a new plug, and not solve the problem of why it backfired in the first place. Somewhere in the; jetting, altitude, ignition, fuel grade, intake, valves, etc. might have caused it...any changes here? Or, is it possible that you were on the kill switch during deceleration? That could cause a serious backfire! Good luck!

Something like that happened to me last spring. I had replaced the fuel hose,(tried to run an in line filter), and it was starving the motor for fuel. It would run fine 'till high speeds then backfire and die. After sitting a while it would start. From that experience I would suspect fuel delivery.

I don't think that the kill switch was it, because it didn't bog, or anything...just right after I decelerated, I went to apply the throttle to make the turn, and POP...and it died. It really had me worried about it jumping a tooth on the cam chain, or something, but the bike is only 6 months old.

I just double checked the fuel line and it's okay. The bike has never backfired on me, or neither has been hard to start until today.

My jetting should be pretty close, as I was at 2000ft sea level, in CA, and when I ordered my jetting kit, I ordered it for sea level, because I knew I was coming here, so the bike should be plenty rich, but I haven't checked it since I got here. I'll pull the plug tonight and take a look at it.

I just remembered that I never did do a valve adjustment after I got the bike...stupid me...maybe that's the problem?

Any help here would be greatly appreciated...

Billy, my previous bike, a zx6, had your symptoms coming

off fast freeways. Shop fixed it, said valve clearances were

too tight. I recall when I first got my pig 29 months ago

having a few times when I thought the decompression

thingies were sticking . It cured itself.

Suggest you check your clearances, then carry a spare plug

when next out. Changing plug is only a 4 minute job if you

carry a 12 inch piece of string for tieing back the

handlebar decompression lever to aid access.

cheers, Craig

The valve adjustment procedure is nicely outlined in the OEM service manual. If you don't have one, check out the following link, but you'll have to be a Yahoo XR650R group member, which I know you already are.

Also, you mentioned your bike came from California. Did you remove your California smog crud yet or is it still there?

Sounds to me like a fuel issue as described in previous posts, but it can't hurt to adjust the valves as they surely need it by now. Your spark plug should help to tell the story of your backfiring.

If this is still kicking your butt after trying everything else, take a look at your AVC (Air Cut Valve) on your carb. The ACV is supposed to make the air/fuel mixture richer upon deceleration. The ACV is a diaphram that partially blocks the air bleed system in the low speed circuit (making it richer) whenever there's high manifold vacuum such as when you let off the throttle to decelerate. Sometimes these diaphrams deteriorate over time, but I doubt this is the case with your bike. If its bad, you'll notice it being cracked or torn and if it looks good, then it probably is. It's just something else to check after trying all the obvious stuff.

Fuel delivery can be also be affected by the vent tube or the tank filter screen.

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