[mastercylinder]

imported post

hi adjusted the carb inputs with a manometer but after if warms there are puff sounds [small backfires] coming from the carb intakes, during the adjustment the manometer tube would be ejected from #1 carb with a sharp crack .. hmmm what in the hell is going on?? aarrgghh...

 

[Bagmaster]

imported post

Possible valve sticking open. Pull the valve cover and check the valve clearances on both cylinders on that side while you're at it. Also could be from carbon build up on the valve stem holding it open. Check the intake valve.

 

[mastercylinder]

imported post

hi how do you clean the valves of crap and carbon?? is it ok to pour gum remover on top
of the valves? and then drain the oil???

 

[olefart1]

imported post

You could try Seafoam. Use it for a couple of tanks of gas. It just might do the trick. And you could add to the oil an drive for about 200 miles and then drain oil.

 

[TBear]

imported post

Had the same problem with my 83 aspencade, took the carbs apart and found the slow jet plugged. after a good cleaning and it stopped for a while but then happened again, crabs back apart and jet pluggged also float just a bit off. Repalced slow jets with new reset floats and presto no backfire. If i forget to turn the fuel on and start it, as soon as the fule level drops enough in the bowls it will backfire but that is all. Probably a bit of carbon in that cylinder and the lean condition heats it enough to preignite during intake I am guessing.

 

[dan filipi]

imported post

My experience with that spitting back into the intake was the same as TBear described.

 

[DaveO430]

imported post

TBear wrote:

Had the same problem with my 83 aspencade, took the carbs apart and found the slow jet plugged. after a good cleaning and it stopped for a while but then happened again, crabs back apart and jet pluggged also float just a bit off. Repalced slow jets with new reset floats and presto no backfire. If i forget to turn the fuel on and start it, as soon as the fule level drops enough in the bowls it will backfire but that is all. Probably a bit of carbon in that cylinder and the lean condition heats it enough to preignite during intake I am guessing.

Ditto!!!!!!!!