Back fire - 1996 Suzuki DT85

[kelpedup]

Hey everyone, need some help. When it's in the water, I have to feather the throttle to take off or it will stall. It also backfires and when I slow down it stalls. I just replaced the fuel, 2-stroke oil, fuel lines, fuel filter, thermostat, rebuilt fuel pump, rebuilt carbs. Now at idle (out of the water) the engine has an occational miss and backfires constantly. Compression is 120 on all three cylinders. Just thought i'd try here before i took it to a shop. Thanks.

 

[waffles1]

Re: Back fire - 1996 Suzuki DT85

If your plugs are firing correctly you may want to make sure your carbs' jets are adjusted according to spec. To me, it sounds like you are running lean. Good Luck.

 

[99yam40]

Re: Back fire - 1996 Suzuki DT85

I agree, sounds like a lean sneeze.
I would go through the carbs again use carb cleaner and compressed air making sure all passages are clean.
Then make sure you adjust the linkage and carbs as the manual states.

 

[kelpedup]

Re: Back fire - 1996 Suzuki DT85

Carbs are clean... linkage is adjusted to specs. I'm not sure how to test the spark(my manual doesn't say). I'll mess with the air screws and see if that works. I'm thinking it might be a timing or throttle valve issue.

 

[waffles1]

Re: Back fire - 1996 Suzuki DT85

I am not certain on this model if timing could be an issue but if it has a throttle sensor that may also be the problem but I am still leaning to your jet screws not being set correct.

 

[redsandsnook]

Re: Back fire - 1996 Suzuki DT85

Lean sounds right, if it idles real good u have the screw to far out, mine runs best when it idles rough (rich), also come on a plane better.

 

[kelpedup]

Re: Back fire - 1996 Suzuki DT85

Thanks for all the input everyone. I adjusted the air screws to about 3/4 turn out, give or take a little and the backfire at idle stopped. But when I rev it up, it occasionally backfires and the idle becomes erratic and won't go down.

 

[kelpedup]

Re: Back fire - 1996 Suzuki DT85

At a loss. Its not a fuel issue. Still backfires and dies in gear. Backfire is coming from the front of the motor,down below the engine. When it backfires, smoke comes out. Mechanic says it could be the crank seal. I'm ready to lite it on fire!!!!