[panhead59]

I am working on a 66 tripower. Mike Wasson rebuilt the set last fall. Car never really ran much last year. Or at least I never got to this problem to fix it. He has been VERY helpful and these ?'s will go to him Monday if I can't get it "right" by then. Car runs very good but center carb floods after first start, when you turn it off. Of course that also makes for a smelly garage. Engine will restart, after more turns than should be, burns off the excess fuel with an embarrassing cloud of gas, and then runs fine. It has the heat insulaters installed already. Mike said to put a fuel pressure gauge inline as modern fuel pumps are set with to much pressure for this carb. Did that, no help. He also said to make sure the needle valve seat for the cut off was tight, it was/is. Being a new valve and seat, I soaked the float. No leaks. So one other thing that comes to mind is checking the float level. Does anyone know the correct measurement for the float level ? It is at 10/32 now. Any other thoughts on what I could check? Thank you.

[tom s]

mine does the same damn thing every once in awhile.Pisses me off.Have not found out why.Im going to put a fresh fuel filter on.Acts like it gets a spec on the needle and floods some.Drove the car last weekend for about 100 miles with no issue.Tom

[Dick Boneske]

If your float level is 10/32", that's way too high. Specification calls for 19/32", nearly twice the dimension you mentioned. Measure from the soldered seam on the float to the air horn gasket surface. The float drop spec is 1 3/4". The float level and drop needs to be reset, but I believe float setting is not your only problem.

If the carb overflows only when shut off, problem is a small leak allowing gas to leak into the float bowl while there is still pressure, but no gas being used by the engine. Mike's suggestion of checking the seat to see that it's tight would be the first thing I'd check. Then, check the float to see it's not leaking as you already did.

It is common for needle/seats to leak when the engine is first fired after carb rebuild or disassembly/reassembly due to small pieces of dirt on the needle/seat. Sometimes, dirt imbeds itself in the soft needle tip and won't seal. Inspection under a magnifying glass may show you the problem. When the airhorn is off the carb, it's easy to create suction with your mouth on the fuel inlet with the airhorn inverted to see if any air leaks past the seat. This is a simple, accurate check.

If none of the above helps, I'd replace the needle/seat with a new one and see if the problem goes away.

[chrisp]

One problem with ethanol fuel & a non ethanol compatible fuel filter it starts to deteriorate it & becomes unattached inside the housing & breaks down & no longer is it a filter . The repo. blue filters are no good for this type of fuel .

[goat1964-2004]

I agree with Dick. Check your float.

[chrisp]

Originally Posted by goat1964-2004

I agree with Dick. Check your float.

I agree as well .

[panhead59]

Float is not leaking or filling up with gas at all. I submerged it in gas, let it sit awhile, no gas got inside float. It is however a black plastic type, so would that measurement from the seam ( it does have a seam, just not a soldered one) be the same 19/32" ? The needle looks new (as it should 'cuzz it is!!) with just a very slight circle on it where it is sealing shut. Or at least trying to shut. I'll recheck float level and drop. Thanks for the replies.

[tom s]

I know my float is correct I suspect a small piece of crap gets loose and stuck on the seat.It has been on the car for maybe 8 years or so and just does it maybe a couple times a year.Tom

[Dick Boneske]

Yes, that is a common syndrome with Tripower setups. I don't understand why, as the single two barrel Pontiacs don't have that problem--and the center carb is nearly identical to those.

I eliminated that problem several years ago--I use only the disc-style needle/seat assembly's on my own setups and those that I restore. Since I've begun using them, I've not had a single instance of an overflowing carb--except one instance with my rear carb with a leaking brass float and a friend who discovered the Needle/seat assy. was not tight in the airhorn. You can get them from Tomco and other suppliers of carb parts. The part number is 555.

[panhead59]

Measurements are definitely off right now. Drop off by 1/4" !!! Now, is the float level set measuring from the gasket surface to float seam at the pivot end or the opposite end? There is quite a bit of difference. Original measurement taken from bottom of float, or edge closest to air horn, which is obviously incorrect. Point of measurement on float for drop ? On seam also ? Which end? Thanks

[panhead59]

Please disregard post #10. I've found an instruction sheet on Rochester carbs that give measurement locations for both brass and plastic floats. This computer really makes a huge difference. Not any comparison to getting info on my first 66 gto in the early 70's!!!!

[bill ryder]

Certainly correct!! Computers have changed the whole aspect of repair and RESTORATION. That is why we can now easily over restore our cars. Pictures and info and friends at our finger tips. The world has changed a whole lot in 40-50 years!!!! "Bill"!

[Tom Vaught]

Of course you know and the pics should show the measurements are with the top inverted for the closed position of the needle (with the bowl gasket installed) and the top is turned over to the normal install position for the float drop measurement Which also is the needle farthest open position.

Tom V.

[Jack Gifford]

Originally Posted by Dick Boneske

... I use only the disc-style needle/seat assembly's...
You can get them from Tomco... part number is 555...

Dick- is the 555 a direct fit in a Rochester 2GC? Does it flow as much fuel as an original tapered needle & seat?
Thanks.

[panhead59]

Tom,
Yes, I know. Thanks.

[carbking]

Originally Posted by Jack Gifford

Dick- is the 555 a direct fit in a Rochester 2GC? Does it flow as much fuel as an original tapered needle & seat?
Thanks.

If you use the "wafer" valve, the float drop must be alsolutely perfect!!!

http://www.thecarburetorshop.com/Fuel_valves.htm

We have acquired many of these new over the years from shops whose inventory we purchased. ALL of the wafer valves (the Parker design is fine) we recycled as scrap brass! Use them if you wish, but make certain the float drop is set so the wafer cannot turn sideways. Have seen many that did!

Jon.

[panhead59]

Tested Mr. Gasket (China junk!!!!) fuel pressure regulator as suggested by Mike Wasson. He was right. Way to much pressure. He said 4 lbs. max and he likes em around 3 1/2 for tripowers. He recommended Holley as the Mr. Gasket (local auto parts store) are notorious for being inaccurate and prone to leak. Ordered from Summit. The main symptom was adjusting screws on throttle body did nothing. Excessive fuel pressure was bypassing idle circuit. Will update next weekend as I cannot find the Holly regulator locally. BUMMER.

[Tom Vaught]

The Holley red ones were not that great for moving fuel for drag race use, same deal for even two of the Blue regulators, (one for each bowl) but they typically do control well vs the Chinese junk.

For 11 second or better time cars the Holley 7/16" ball regulator works very well.

The best set-up though is the Tanks,inc fuel tank, Walbro high pressure EFI fuel pump, EFI fuel regulator, and a good return line matched to the inlet line size. Everything is OEM quality and SHOULD last a long time in a collector car (even with deathahol for gas).

Tom V.

[Kenth]

I´m using the Carter P4070 5psi electric fuel pump (no checkvalve in the pump building pressure at shut-off engine) as i´ve noticed 21 psi in line to carbs after a few minutes shutting the engine off and carbs flooded like there was no tomorrow.

Also i´m using factory correct style/sizes inlet valves, .118" in center carb and .086" in outer carbs.

Center float is set 19/32" and outers 21/32".

Not a problem in 20 years.

[Kenth]

Also, it´s ESSENTIAL to use the correct size float.
Using the small bore brass floats in 1966 Tripower carbs WILL make it run too rich with possible flooding.