Oliver 880 with Zenith #12259

coers86 · Aug 2, 2020

So my dad has a Oliver 880 with the zenith #12259 carb. has new ignition kit, new sediment bowl, new inside fuel filter, and rebuilt card. For some reason when we're pulling it at the pulls seems to sputter and spit. But when running it at high idle just sitting at around 2000 room seems to run fine. Anyone have any ideas what's going on or what could be adjusted? He was thinking it might need more fuel? And if so I'm not sure what screws or jets to adjust. Can't find a diagram for this carb online for adjusting.

ziffel · Aug 2, 2020

Start and warm up engine. Idle down and set idle RPM's. Set idle air adjustment screw until engine runs smoothly. Then speed up
engine to full throttle. If it balks open the high speed adjustment screw until engine runs at full throttle smoothly. While
running at full throttle turn high speed screw clockwise until engine starts to balk. Then turn out until engine is again running
smooth plus an additional 1/2 turn. The book sez to idle engine back down to idle for a few seconds and then to give it full
throttle. It should run up to speed normally without a lot of black smoke. That would be a rich condition.

coers86 · Aug 2, 2020

would you happen to have a nice diagram for the carb? I can't seem to find one that shows recently what each screw or adjuster is.

(quoted from post at 05:24:35 08/02/20) Start and warm up engine. Idle down and set idle RPM's. Set idle air adjustment screw until engine runs smoothly. Then speed up
engine to full throttle. If it balks open the high speed adjustment screw until engine runs at full throttle smoothly. While
running at full throttle turn high speed screw clockwise until engine starts to balk. Then turn out until engine is again running
smooth plus an additional 1/2 turn. The book sez to idle engine back down to idle for a few seconds and then to give it full
throttle. It should run up to speed normally without a lot of black smoke. That would be a rich condition.

ziffel · Aug 2, 2020

No sir I don't. The high speed screw is down low on the float bowl. The air idle screw is up near the top. It is used to adjust the
air fuel mixture at an idle. Too rich or too lean will result in rough idle. The engine idle screw is part of the linkage that
moves the throttle butterfly when you pull the throttle down to speed up the engine. It has a spot to use a small screw diver to
adjust the engine idle speed.

coers86 · Aug 2, 2020

yeah I feel the idle are good for low where high but think maybe it needs more fuel when it has a load.

J.Wondergem · Aug 2, 2020

The high speed adjustment is the T at the bottom of the float bowl.

coers86 · Aug 2, 2020

thank you. so adjust that one at high idle and that should help when I have a load at high idle?

chucksoliver77 · Aug 2, 2020

Dad is most likely right, if you have an inline filter take it off. You can take the sediment bowel of and drill the 2 holes out where the gas runs into the bowel and you also have the float valve drilled out by a carb shop like Treadwell Carb.

super99 · Aug 9, 2020

Have you tried pulling the choke out a bit when it spits and sputters to see if it runs better? If that helps, open the load screw some more.

Oliver 880 with Zenith #12259

coers86

New User

ziffel

Member

coers86

New User

ziffel

Member

coers86

New User

J.Wondergem

Well-known Member

coers86

New User

chucksoliver77

Well-known Member

super99

Well-known Member

Similar threads