Alright... I currently own a 1999 trailblazer 250. I've been having a problem with it backfiring and the muffler or w/e the tube is that comes out of the front of the motor coming slightly out of place so the bike sounds loud as hell (this happens when it backfires). Yesterday this happend for the third time except that one of the springs holding the pipe on broke when it backfired. My questions are... 1. How can I stop this backfiring and 2. How on earth can I get a spring back on. Those things are insanely tight.


Thanks in advance for any advice given.

 

You can buy a brake spring tool from Harbor Freight for about $1.99. It was a real knuckle saver for me. I have used a busted flat blade screw driver that I grinded a notch in before. It was better than pliers. Your jetting may be off. I had that problem too. New springs to replace the old ones helped as well.

 

I FOUND THIS ON ANOTHER FORUM, SEE IF THIS HELPS: [img]i/expressions/face-icon-small-smile.gif[/img]

A fairly common occurrence on Polaris machines as they get older is for the ETC to get out of adjustment. This is due to throttle cable stretch. The purpose of the ETC is to cut power to the spark plug in the instance of a throttle that becomes stuck or frozen open. The ETC does this with a spring-loaded set of electrical contacts in the throttle lever housing. As long as there is enough tension to overcome the (light) spring in the housing, the contacts do NOT touch, resulting in normal operation. Whenever the contacts touch, you can lose spark. If your engine seems to sputter/backfire upon de-acceleration, and doesn't always idle smoothly, or, in extreme cases, not well at all, try adjusting the ETC.
Follow the throttle cable where it exits the housing on the handlebar. Where it 'bulges', slide back the cover. There will be a threaded adjuster. Loosen the locknut, and lengthen the adjuster so you get about 1/16 to 1/8 inch of free travel at the end of the throttle lever. Now start the engine. Turn the handlebars to the extreme right and left to be sure the engine doesn't speed up (do this in neutral). If the engine revs, loosen back the adjustment so it doesn't. If it maintains idle speed from full right to left, you got it right.

 

i dont know if that has anything to do with your problem or not, but it was worth a try. I tried to post the website that i found it on, but it wouldn't let it post, it said it was "FORBIDDEN" [img]i/expressions/face-icon-small-sad.gif[/img]

 

What are the conditions of the backfire? Throttle on? throttle shut? decellerateing?
If it happens on decelleration, the pilot circuit is too lean, check for air leaks in intake, and exhaust. If thats ok, then the air/mixture screw needs to be richened up.

 

Wow, thanks for the info guys. I love this forum! My bike tends to backfire in reverse if revved to high/quickly or right when I crank the engine. Btw, I use the pull start... my electric start crapped out on me a while ago.

Thanks again!

 

The problem with your bike is not a problem at all. Looking at your left hand side controls, do you see a (yellow?) button w/ the word REVERSE/OVERRIDE by it? Push this button for full power reverse. The is a governer on the reverse gear, so you don't go too fast. Try using this button in reverse next time, that should fix the problum. BE CAREFUL, the machine will go fast in reverse w/ OVERRIDE pressed!!

 

I do use that... Also it backfires when I start the quad.

 

my bad, sorry[img]i/expressions/face-icon-small-blush.gif[/img]

 

Backfires are caused by a lean idle circuit. Either the intake has a leak, the exhaust has a leak, which could be the problem, if it doesnt get hooked up right, or the idle circuit needs richening, Try pulling on the choke and see if that gets rid of the backfiring, if it does, the air/mixture screw needs to go richer.