yam f80

[grahamd7504]

Hi, my yam f80 (Carb'd) is making a popping noise throught the air filter above idle? i have adjusted the throttle sensor switch? what is the cure ?? reguards Graham

[rodbolt17]

there is no sensor switch.
however popping from the air box typically indicates a lean fuel mix,clogged carbs, or a burned intake valve.

[grahamd7504]

yam f80

i will start with the carbs (strip and clean) then a comprestion test ? thanks for your advise Graham

[rodbolt17]

I prefer a leak down test over a compression test.
however do one or the other BEFORE carb cleaning.

[grahamd7504]

mixture screw

how many turns would i turn the mixture screw out?? its currently at 2 3/4 turns out the popping is not constant ,so i think the inlet valve could be ok ??? Graham would you recommend petrol for the leak down test, and at tdc on all cylinder individually, many thanks for your invaluble advise Graham

[grahamd7504]

f80 carb problem

ive got it running sweat now, stripped the carbs blown them trough with air line ) just need a run out on the water now
before it was'nt revving above 3000rpm with out spluttering and popping and fading ,fingers crossed all is well now?? a big thanks to the yamaha forum