05 Big Bear backfire

Busta Nutt · September 27, 2009, 05:01:59 PM

Out of the blue my Big Bear started backfiring out of the carb. You can feel it blowing out of the air intake. So that makes it not idle. other than that it runs fine when you are on the gas. I've cleaned the carb out twice and this has got me stymied. Any help would be appreciated.

Baileygunns · September 27, 2009, 09:13:55 PM

Adjust the valves?

Busta Nutt · September 27, 2009, 09:35:04 PM

yes I did adjust the valves. did not make any difference they were within spec.

MedicMudder · September 28, 2009, 12:02:36 AM

might have a vacuum leak or the carb might have wiggled loose sucking air might be running to rich.Might have a piece of sand in the carb that you can not get with carb cleaner. thats all I got to say bout that

Busta Nutt · September 28, 2009, 12:09:23 AM

If the carb wiggled loose it would be running to lean I do believe. If there is something in the carb I'll be a monkeys uncle had it apart twice. It is a stock machine that does not go under water. But I do appreciate your help.

Chillinthemost · September 28, 2009, 01:09:36 AM

Did you take the pilot jet out and try to look through it? The hole is really small and it is easily clogged. It is so small that I usually use a piece of wire cut out of piece of 12ga. stranded wire or whatever I can find in the tool box that is small and wont booger the hole. Just make sure that when held up to light that you can see through it. 99% sure that will be your problem.

Busta Nutt · September 28, 2009, 10:43:54 PM

I cleaned out the pilot jet and it was still doing it. So I revved her up to about half throttle for a few seconds and let off the gas and it was idling kind of high. Look down to adjust the screw there and the exhaust pipe was glowing red. So i let it idle a bit and it seems to be okay now.

Mudneck · September 29, 2009, 01:04:37 AM

Maybe your just to heavy for that 150

Busta Nutt · September 29, 2009, 09:57:33 AM

that could be

Mars · October 13, 2009, 01:02:50 AM

Quote from: Busta Nutt on September 28, 2009, 10:43:54 PM
I cleaned out the pilot jet and it was still doing it. So I revved her up to about half throttle for a few seconds and let off the gas and it was idling kind of high. Look down to adjust the screw there and the exhaust pipe was glowing red. So i let it idle a bit and it seems to be okay now.

Sure reads like an intake leak. Check the carb mount o-ring at the head.

Air-Med · October 14, 2009, 09:31:26 PM

Quote from: Busta Nutt on September 27, 2009, 05:01:59 PM
Out of the blue my Big Bear started backfiring out of the carb. You can feel it blowing out of the air intake. So that makes it not idle. other than that it runs fine when you are on the gas. I've cleaned the carb out twice and this has got me stymied. Any help would be appreciated.

Have u check ur oil level?? That problem can be easily a crack piston ring, bend valve, so basically u need to perform a leak down test and a compression test to start... Oil Level can tell u alot if u are missing some

Busta Nutt · October 14, 2009, 09:49:57 PM

the oil is always good I change it often. this weekend I will check the intake o-ring.

Air-Med · October 15, 2009, 02:22:14 AM

Quote from: Busta Nutt on October 14, 2009, 09:49:57 PM
the oil is always good I change it often. this weekend I will check the intake o-ring.

does it idle okay? The intake o-ring will make it idle high or hard to idle

05 Big Bear backfire

Baileygunns