[Towtruck]

Hi, I'm new to this board and to ATVs. I have a 2000 Foreman ES. Problem is it backfires. Any ideas as to why? I'm thinking its running rich. But it should have the stock jetting. Will adjusting the mixture help this? The bike doesn't smoke and runs great. It just gets annoying with the backfireing. But it also doesn't do it all the time and it will do it hot or cold, more so when cold. Some days it won't do it at all. But mainly when its coasting down a hill. I would be thankful for any suggestions.
Kelly

 

[eustismudder]

How does the bike perform otherwise. Is it sluggish at all or does it seem to just get up and go.

 

[Towtruck]

It runs great. No hesitation, stumbling, or misfiring. Also I haven't noticed any black or other smoke.

 

[shooterman]

back firing or crackling in the exhaust on deceleration or on downhills is associated with a lean idle circuit. it is commonly associated with engines with modified exhaust and the main jet was rejetted but not the idle/slow speed jet. it is a harmful condition that if not corrected could damage the engine. if you have not made any mods and the problem recently started, i would look at a clogged idle jet or an intake leak between the carb and the head. i just corrected the exact problem on my honda which was caused by the atv being assembled without an intake gasket. oopsy!!

 

[Railroader]

Mine backfires every now & then. I guess it won't hurt if it does it every
now & then.

 

[Towtruck]

Somedays it does it quite a bit. Others it won't do it at all. The main problem is it makes the people I'm riding with think people are shooting at us.
I just don't want to hurt the motor. Probably within the next month I'm going to install the LMF pipe, jet kit and K/N filter.
Also I sprayed ether around the carb while it was running to check for a leak and nothing. The tail pipe looks to be running a little rich. Haven't tried reading the plug yet. I'll just keep trying things maybe I'll stumble onto the problem.
But thanks for the advice. I'm thankful for any and all.

 

[ForemanDan]

QUOTE ("Towtruck":amzu1qzx)

Somedays it does it quite a bit. Others it won't do it at all. The main problem is it makes the people I'm riding with think people are shooting at us.

Yeah, the last time we were riding at Windrock, the locals went for their guns when we went by.
Towtruck, just get a new 500. You know your wife wont mind.

 

[muddin500]

my 500 when i took the spark arrestor out would shoot blue flames bout a foot long everytime it would back fire now with the hmf it shoots out bout 2 foot with pops done it since it was new

 

[Guest]

Mine backfires once in a while when I turn it off. It usually backfires only once and doesn't do it all while I'm running it any other time. It runs great and has backfired since I bought it a few years ago used. Any advice on what causes this? Thanks.

 

[meathead1]

drain carberator sounds like water in the bowl