F80b

[mmeric8802]

Hi,
I have 2002 4 cycle Yamaha on 19' C Dory, she was popping at 2000 rpm range i removed the carbs and clean them there was a plastic cap on one of the jets ? didnt make any sense, put the carbs back on the engine stars right up but little rough at idle if i lean the carbs idle improves but popping comes back if i richen the mixture idles rough but doesnt pop i check compression and every hole got around 110, pump some air into them didnt hear notting comming out, check ignition all of them firing , when i spray carb cleaner around intake manifold she stumbles and want to stall i dont think i have vacum leak anywhere, when i line the timing marks cams look tooth off , realy confused with this motor am i missing something any help be great thanks in advance

[rodbolt17]

your carbs are still not assembled correctly.
your carbs are not correctly synchronized.
other than that its all ok.

[mmeric8802]

F80b

Thanks Rod,
Assembled correctly didnt get that part??

[rodbolt17]

dont play with the cam timing.
its a non clearence engine and you can whack intake valves.
each pilot fuel jet had a rubber plug over the jet bore from the factory.
it takes a 4 channel manometer to correctly sync the carbs after removal.

[mmeric8802]

F80b

thanks Rod ill try to buy one and synch m

[grahamd7504]

i have the same problem f80 aet

hi when you find out what your problem is please let me know
i have a 5mtr alaksa 500 fishing boat, should fly but sound like we are sharing the same fault i was out on saturday and for the second time had this fault would be greatfull for a reply thanks Graham, UK...

[mmeric8802]

F80b

Hi Graham ,
What kind of motor u have n what kind of problems u having??

[grahamd7504]

possable carb trouble?

hi, i have a yamaha f80aet 2003 on a alaska 500 (5mtr)fishing boat, the outboard is making a weird sound,like a misfire , i had the carbs off for a clean and i have tried to sync them using a type of vacuum gauge for a 4 stroke 4 cyl bike, engine starts well, idle ok ?but under load its chugging? ease off the rev,s then it stops chugging but seems under power? i have altered the throttle censer on the throttle linkage but its still not right (it sounds like a cylinder down ) its got new plug,s and ran great when cod fishing in the winter, i think one of the main jets could be blocked???( reading the guys thread before mine) the fault sounds exactly the same type of thing as mine CARB TROUBLE??? love the outboard but need a solution reguards Graham uk

[grahamd7504]

hi, i have a yamaha f80aet 2003 on a alaska 500 (5mtr)fishing boat, the outboard is making a weird sound,like a misfire , i had the carbs off for a clean and i have tried to sync them using a type of vacuum gauge for a 4 stroke 4 cyl bike, engine starts well, idle ok ?but under load its chugging? ease off the rev,s then it stops chugging but seems under power? i have altered the throttle censer on the throttle linkage but its still not right (it sounds like a cylinder down ) its got new plug,s and ran great when cod fishing in the winter, i think one of the main jets could be blocked???( reading the guys thread before mine) the fault sounds exactly the same type of thing as mine CARB TROUBLE??? love the outboard but need a solution reguards Graham uk[/QUOTE]