The Stovebolt Site Forums The Shop Area Engine Shop 235 carb prob, i think

I've got a 235 in my 53 with a Rochester single. it has never ran like I think it should. got it to where it starts great, idles good. it will set there and idle good till the cows come home. so I go for a cruise, maybe 10 minutes at 50 mph. pull up to a stop sign and it won't idle and quits. if I get it started I have to keep the engine running at a pretty high rpm or it will die. some times I get it home park it and it'll set there and idle beautifully (sometimes not) but if I walk away from it and come back later it starts right up and we go through the same scenario. I've cleaned the gas tank/lines, replaced the fuel pump had the carb apart a half dozen times. Float level is at 11/8 closed and 11/2 drop (to spec I think). needle vale seem to shut off the fuel, at least statically.
I've changed plugs, set the timing, adjusted the valves and replaced the coil resister with an internal resisted coil.

To me it seems like a flooding issue, but i'm hesitant to go back into the carb unless I know what i'm looking for..about at wits end !!

Any idea's

Yes, it's flooding when it's hot. Try lowering the float level by about 1/16" to give it a little more upward pressure on the float before the gas is able to overflow into the venturi when the engine is warmed up. Also be absolutely sure the float doesn't have a leak. Give it a good shake and listen for liquid sloshing around inside. Just a little gasoline inside the float will make it too heavy to get enough lift to properly shut the needle valve off at a stop after cruising a while.
Jerry

I ran into similar running conditions when the '47 became road worthy. The Rochester single-barrel was replaced with a Carter YF and the dual action fuel pump was replaced since it was producing about 8-9 psi. Additionally, I found that my new reproduction 'vented' gas cap wasn't venting at all. It might be just that simple, try removing the cap and go for a spin.

I would suggest looking at your plugs. With regular driving they should be a nice tan color.

Hi. I had a very similar problem. 1962 235. Ran great on the highway, could idle well for hours, sometimes would want to stall at a stop. Turned out that the throttle shaft was worn and the butterfly in the carb would close in a different place sometimes, and when it did, it wouldn't run right. On inspection, I could see the shaft was loose, and when I took the carb off, I could see the throttle plate closing in different places, sometimes covering the idle ports. I found a NOS carb on eBay and problem solved.

There is probably a way to drill out the throttle body and put new bushings in, or otherwise tighten up the fit. I oil mine periodically now to try to keep the wear down.

Hope this helps. Good luck.

I would suggest checking the plates in the distributor to see if they stick when hot. Or, a pertronix conversion still running a generator?

The fact that the issue seems to be intermittent suggests ignition. Most carburetors (even Rochester B's) have very little personality.

Just my guess.

Jon.

Jon, the complete 235 distributor housing turns for vacuum advance- - - -it has no "plates" to stick in the advanced position. The centrifugal advance weights could be sticking, however.
Jerry

Thanks Jerry, lots of different distributors, and not my field; but one sticking in the advanced position will give the results mentioned by the O.P.

Jon.

Hot Rod Jerry... I think you nailed it. First time I think I set it a bit too much and it did all kinds of crazy things. So I re-adjusted to about 1 5/16, took it out for about 5 miles with numerous stop signs and ran fine. I will have to run it for a while to gain back my confidence but here's hoping... THANKS;

Handy Andy... the gas cap didn't make any difference, but good call.

i'll check the plugs after driving a while

I do want to go with electronic ign soon and convert to an alternator but had to get the thing running right first.

This was all good stuff... Thanks guys

Oh.. if it acts up on a long run, I'll be back...