357 problems

[what a feller]

Hi all, had a problem with my 357xp a while back where the gasket on the front of the carb hard split sucking too much air into the block and cutting the saw out, I have replaced this gasket and the carb has been re tuned, the problem now is that it will run for a minute and then make a noise like a car backfiring and then cut out... any suggestions?

[spudulike]

Hi all, had a problem with my 357xp a while back where the gasket on the front of the carb hard split sucking too much air into the block and cutting the saw out, I have replaced this gasket and the carb has been re tuned, the problem now is that it will run for a minute and then make a noise like a car backfiring and then cut out... any suggestions?

 

Any sign of the saw backfiring is likely to be the flywheel key has sheared and now the ignition timing is running very retarded.

 

Other than that, perhaps the saw is running rich and unburnt fuel is igniting in the muffler.

[what a feller]

Cheers man, the little spring that holds the trigger pin on the carb is a little misshapen too, is it possible that it isn't returning throttle quick enough and dumping excess fuel into the block?

[spudulike]

Cheers man, the little spring that holds the trigger pin on the carb is a little misshapen too, is it possible that it isn't returning throttle quick enough and dumping excess fuel into the block?

 

No, it is a retaining spring, it wouldn't cause this. It could be a dodgy coil, worth checking the flywheel/coil gap with a business card!

[Cut4fun]

Also while you have it tore into checking. Make sure you have updated metal intake clamp.

 

Modified old partition or new updated one to use metal intake clamp.

 

Remove the auto decomp feature if your saw has it. Problematic buggers.

 

199 carbs known to give problems too. When they run good their sweet, but when they go wonky they are grrr.

[what a feller]

Cheers guys I will check it out, might end up sending it to you for porting spud

[spudulike]

Cheers guys I will check it out, might end up sending it to you for porting spud

 

You won't recognize it if you do:thumbup:

[what a feller]

That's always the dream buddy, toms had a few ported from you and his 357 purrs like a kitten

[spudulike]

That's always the dream buddy, toms had a few ported from you and his 357 purrs like a kitten

 

Mmmmm, They didn't come to me that way:sneaky2:

[adw]

When you say gasket on front of the carb, what are you refering to? the only gasket is on the back of the carb if it still has the compensator carb, it is also possible to fit this one up side down, as the carb has no breather hole in the metering cover, it would upset the carburation and run terrible.