Give it a notch more gas with the main jet needle.

 

Do you think a needle adjustment would be too much fuel at wide open throttle and begin to "dog" the machine under a load or up hill? Or is this adjustment small enough that it shouldn't make a difference? Will this adjustment bring in enough fuel when coasting down a good hill and not on the throttle at all?

 

Do you think a needle adjustment would be too much fuel at wide open throttle and begin to "dog" the machine under a load or up hill? Or is this adjustment small enough that it shouldn't make a difference? Will this adjustment bring in enough fuel when coasting down a good hill and not on the throttle at all?

 

Should be fine, Ive done this to several machines and it makes them run better, you can always put it back if you dont like it.

 

I'll work on it this weekend if I have time and keep you posted. (I'm hoping I'm getting closer.) Thanks guys!!

 

I had a similar problem with my 700 twin...Turns out when the engine runs lean it gets really hot and mine melted the rocker cover just above the exhaust manifold. You might want to replace all the gaskets if you think it has been running lean for a while.

 

My 700 twin was also doing that... course i did several things and i dont know which one for sure cured it...
1. Intake tube between carburator and filter:dryrotted
2. Intake tube(intake manifold) between carburator and engine head:
dryrotted
(they can be hard to tell if they are dryrotted/split but deffinatly check them)
3. I had a very very tiny exhaust leak were the Y comes into the single pipe, (replaced the gasket)
4. Check your plug wire(s), any spot that is slightly worn tape it up or buy a new wire.

I actually think it was the exhaust leak causing this, but the intakes cut down the popping quite-a-bit also.

 

Im sorry, I didnt pay attention to the thread, I thought you were blowing flames out your exhaust. But I would deffinatly check your coil (they can occasionally malfunction and delay the spark) and intakes like I stated earlier.

OH!!! one other thing that I did while trying to get more power from my 700 was run without the airbox lid, and then without the intake neck ontop of the lid. Both of those did result in popping from the intake and one back fire then i put it back to stock. So you might check your box and make sure its not cracked and that your seals arent wore out.

 

Hi guys, I jacked with the ATV carb again today. I moved the clip on the needle down one notch to let in more fuel. It did not seem to effect performance at all (runs like a champ!), but at the same time I went down the neighborhood hill and again POP... backfire again. (No flame I don't think). As far as checking the coil, might you suggest I just purchase and replace it or is there a way to check the coil?? Also, I checked for leaks (intake as well as exhaust) and didn't see anything jump out at me. Thanks again for your help & suggestions!!

 

Have you tried adjusting your float?? It sounds to me like this is probably the most likely cause, because your getting a lean condition temporarily and not all the time. You need more gas in the float bowl...this cured my lean condition when I had the same issue.