C3 hot starting problem

[Bruce Mitchell]

1968 400 horse (hydraulic) 427 with 3 holley 2300's and 4 speed.

Starts fine when cold (one pump and immediate start).

When warmed up, after stopping for a while its very hard to start, only starts if pedal is held to floor, and when it starts its very smokey and rich for a few seconds.

So, I figured I had fuel leaking into the throttle bores when I stopped the motor. So, I changed all three needle/seat combinations, and set float levels just at or below sight holes--result, no change.

Then, I dropped the float levels on all three quite a bit--result, no change.

I checked temperature of the carbs themselves after I stop with an infared thermometer, and they are only at 180-190 degrees. that shouldn't be enough to cause percolation, should it?

the carbs are very clean, and to be sure I checked the filters (bronze) and they are fine, and I ran a tank of carb cleaner/gas through to be sure. Do you think percolation (or heat soak) is the problem?

[Clem Z.]

Re: C3 hot starting problem

check for warped metering bodies,main bodies where the metering bodies fit and throttle base plates.

[Wayne P.]

Re: C3 hot starting problem

Right on with the warping! The last one I fixed required .030" milling of the main body to get it flat.

[Clem Z.]

PS if the metering blocks are warped

you can not mill them flat they must be replaced or straighten in a "jig" using a arbor press

[terry plata]

Re: PS if the metering blocks are warped

Clem and company,

Oddly enough I have seen more damage to the main body by over tightening the bowl screws. the screw holes are pulled into the soft gasket material and you have a warp. The metering blocks tend to escape this abuse because they fairly stoug, not threaded so take little stress. A straighedge across the body will reveal if the problem lies there. EASY ON THE BOWL SCREWS!..... TPlata