its happened twice already. both times when i let off the gas going downa hill. is this a problem and what coudl i do to fix it? i jsut have a feeling i should find out now be4 i find out what happens next.

 

Its probably a little low on gas. Turn your air/fuel screw out a 1/4 turn at a time until it goes away. Make a note of how far out the screw is stock.

 

Its a lean condition, either intake leak, exhaust leak, or, most likely, the mixture screw needs adjustment.
This is from the mikuni carb website.
"
: Backfires in Exhaust

The popping is a result of the air/fuel mixture becoming very lean when the throttle is closed and the engine is rotating well above idle speed. It is also necessary that the exhaust system have rather open mufflers.

Why This (normally) Happens:

1) When the throttle valve is in the idle position, fuel does not flow out of the main system (needle, needle jet, main jet). Fuel is only delivered to the engine by the pilot (idle) system.
2) The combined effect of the closed throttle and elevated engine rpm is to create a fairly strong vacuum in the intake manifold. This vacuum, in turn, causes a high air flow rate through the small gap formed by the throttle valve and carburetor throat.
3) Under these conditions the pilot (idle) system cannot deliver enough fuel to create a normal, combustible air/fuel ratio. The mixture becomes too lean to burn reliably in the combustion chamber. It gets sent into the exhaust system unburned and collects there.
4) When the odd firing of the lean mixture does occur, it is sent, still burning, into the exhaust system where it sometimes ignites the raw mixture that has collected ---- the exhaust then pops or backfires."

 

Seems like you always have good info in your posts Hondabuster. Are you dealership personnel or just a smart enthusiast?

 

could it also be because the choke **** is out to far? meaning if i never completely turned the choke off.

 

a backfire on deceleration is usually due to a lean condition. if your not on the gas at all, it will be your slow circuit. since the ranchers have a keihin carb, you won't have an air skrew. you can increase the pilot jet size or turn your FUEL skrew out alittle bit at a time to richen up the mixture from idle to around 1/8 throttle. this should take care of the minor backfiring problem you have. you may notice that the backfiring is worse in colder months. if this is the case, it is because the colder air is more dense and leans out the mixture. so in cold temps, you want to richen up your jets and vice versa in warmer months.

 

backfireing? its normal...my 3 wheeler back fires all the time when you let off the gas..while keeping it in gear....and its been doin it since 1985......my brothers road star has straigh pipes...and it back fires now...its common...espically when your riding down hill..

 

But doesn’t when u open the choke add more air and keeps the same amount of fuel flowing? And I’m not sure if that would be lean or rich, I believe rich is when there is too much fuel and lean is when there is to little. So then wouldn’t that mean that if the choke was partly open after the engine has warmed up that there would be more air needed (or less gas for the air to fuel ratio) so wouldn’t that be lean?

 

dzzy, thanks for the compliments. I pm'd you. Im just a guy with a interest in motors and mechanical stuff. Musclecars, motorcycles ,atvs snowmobiles.....
I also respect the infomation you give, you seem to know quite a bit more than i do.

 

Hondabuster, check your PMs.