runability problems

Joined
Apr 16, 2004
Messages
379
Location
elizabeth,co
well for awhile my cruiser ran like a champ,couldnt be stopped,and i loved it.then the other night all of a sudden things changed.
here's what i got.2f with f carb.
when its idleing its fine.but the second you go to take off it just kicks and bucks and pops,the tack jumps all over the place,the whole nine yards.at times under hard acceleration i can get it to smooth out but not often.it seems to have no power and just buck and pop.
this is what i did,cleaned fuel filter,cleaned carb,set timing and fuel mix.still no good.
what gets me is it was running awesome the day before then in the morning it barely ran.
where do i look to fix this???
points,coil,carb,WHAT??? im goin nuts here.
help guys,its a daily driver.
shawn
 
Last edited:

Pin_Head

 
 
 
Joined
Feb 6, 2002
Messages
14,977
Location
OC, CA
The bucking and popping back through the carb are classic signs of fuel starvation. OTOH, the tachometer needle going nuts is more consistent with an ignition problem. Fuel starvation/lean mixture usually gets much works the more load you put on the engine. Ignition problems are not very sensitive to load, but rather RPM (eg, it would behave the same when you rev it up in N).

Start simple: What is the fuel level in the carb? How much fuel can your pump put out in 15 seconds of cranking with the coil wire cisconnected?
 

krzyabncanuck

USFS HOTSHOT
 
Joined
Apr 5, 2005
Messages
8,691
Location
NC
Did you just top off at a gas station with new gas ? ( bad gas ). Or did it rain that night ?
 
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