By George on Unrecorded Date: Edit

Hey Folks,

I'm putting a NOS JLO 400 in my Chief. It's set up with a Tillotson Carb. The original engine has a Mikuni. The Mikuni will not fit on the intake manifold on the new engine. What's everyone's opinion, swap manifolds or carbs? The one advantage I can see with the new carb would be more flexibility in throttle and choke cables.

Any advice out there?


George

By liflod (Liflod) on Unrecorded Date: Edit

Cut the studs off of the original manifold, drill holes, retap and put the Mikuni on it. It will work with the original manifold. You're right about the throttle and choke cables. With a Tillotson, you can adapt just about anything. The Mikuni is harder to adapt to but it can be done.

By Attex Bob on Unrecorded Date: Edit

I'll second what Liflod said; go with the Mikuni.

By liflod (Liflod) on Unrecorded Date: Edit

I'm getting my machines ready for the trip to Olean on Friday. I fired up the Superchief last night and took it for a blast through the woods. It ran really good at first, but after a few minutes, it would fall on its face when I hit the throttle. If I am thinking correctly, the idle jet feeds fuel up to around 20% throttle than the needle valve pulls fuel through the main jet up to about 75% throttle then the fuel is completely metered by the main jet. It seems the main jet is plugged, so under really light throttle, enough fuel is supplied through the idle jet to make it run and when I try to get fuel through the main jet, it just bogs down.
Am I correct?
What else would cause this?
I am going to investigate after work and I'll let ya'll know what I find.

PS: The Mikuni is still better than a Tillotson !!

By liflod (Liflod) on Unrecorded Date: Edit

I found the main jet clogged with a piece of dirt or rust.