leaking acc pump jets

Plastermaster · Post by **Plastermaster** » Wed May 17, 2006 3:44 pm

I stopped for a cup of coffee today and when I went out to the car the engine gods told me to crack the hood and make sure everything was OK. One of those hunches or whatever. So I opened it up an heard a gurgling from the right carb. I removed the filter and looked in #2 and saw it filling up with fuel above the plate. I grabbed a straw and sucked it out, (yum) checked the oil, (seemed OK) and started the engine. It started fine and idled normally. However when I opened the oil fill cap the fumes smelt a little gassy. I drove home watching the oil pressure. At speed it read a hair under 50, pretty much normal for 200 deg. When I got back home I checked it out again immediately and it was OK but 10 min later it was leaking again. I released the gas cap but there was no pressure build up in the tank. It is vented anyway. So I pulled the fuel line off the right carb and now it is slowly filling up a cup. I'll try turning the car around so the back end is elevated more, but in the mean time if you guys could give me a fix I would appreciate it. I think this is NOT a good situation.

Thanks
Ron

Plastermaster · Post by **Plastermaster** » Thu May 18, 2006 6:04 pm

Well, I thought I had the problem fixed but it returned. The tenbsion on the pump lever seemed loose so I tightend it up and it seemed to take care of it for awhile it seems to be related to heat from what I can tell. I guess I'll have to take the carbs apart again.

Ron

500LbGorilla · Post by **500LbGorilla** » Thu May 18, 2006 6:12 pm

Ron, if you have short manifolds you might be getting enough heat to the carbs that it's causing the fuel in the pump to get forced out of the pump. How long does this occur?

Feel the carbs after you park it and it sits for a while - do they start to get hot? Does the dripping from the pump squirters coincide with some temp increase on the carbs?

I've seem situations where the squirters drooled at idle too, and this was a case of throttle plates pulsing due to insufficient spring tension on the return arms.

If you think it's heat related, check out CB Performance for some thick rubberized vibration dampers. They also isolate heat away from the carbs to some degree and might be just the ticket.

Plastermaster · Post by **Plastermaster** » Thu May 18, 2006 10:01 pm

It does seem heat related but it is also a recent developement. In the past the carbs have gotten hotter and not has the problem. After the car is parked it takes about 10 minuts before it stars and continues for a while, but I have not let it continue because I don't like fuel going down into cylinder and maybe on into the case. The first time I saw it there was about 1/2 " above the plate and it was leaking past into the manifold.

I do have the spacers but the carbs still get up around 200 deg I would guess. Too hot too touch for more than a couple seconds. I figure they get about as hot as the oil temps.

Ron

Oldkoot · Post by **Oldkoot** » Fri May 19, 2006 2:45 am

Is it possible you have a leaking needle valve on the one carb. Maybe not enough to notice when the car is running. You say the gas was slowly filling a cup when the line was disconnected. Maybe that flow is what is seeping through the carb. Im no master mind when it comes to carbs but it was just a thought.

500LbGorilla · Post by **500LbGorilla** » Fri May 19, 2006 4:57 am

Plastermaster wrote:It does seem heat related but it is also a recent developement. In the past the carbs have gotten hotter and not has the problem. After the car is parked it takes about 10 minuts before it stars and continues for a while, but I have not let it continue because I don't like fuel going down into cylinder and maybe on into the case. The first time I saw it there was about 1/2 " above the plate and it was leaking past into the manifold.

I do have the spacers but the carbs still get up around 200 deg I would guess. Too hot too touch for more than a couple seconds. I figure they get about as hot as the oil temps.

Ron

Wow Ron, that's HOT. Mine never get that hot without spacers.

The Koot might be on to something too. You could try a test for the leaking seat. Disconnect and plug the fuel line from the pump and drain all the fuel out of the line to the carbs into a small container right after a drive, and then watch the carbs. If you don't see it that time, he's right.

Could be a float out of whack too. Half an inch is too much to come from just the float bowl. I don't know how you are getting such a seal on the butterfly either.. Normally it will just leak past that straight down into the intake. Once you fix it I'd recommend dropping a few drops of oil in your linkage around the shafts too, because the gas has to be washing any lubrication the butterfly shafts had in them.

Plastermaster · Post by **Plastermaster** » Fri May 19, 2006 8:35 am

I will work on the carbs today. If I disconnect the fuel line, I am thinking the excess pressure might just come out of the banjo.

My guess is the needle valve, due to the amount of fuel.

What really sucks about this is that it could happen anytime if you get a particle preventing a good seat. The idea of fuel in the crankcase makes me sick to think what it could do to the engines life span.

I hear you about the butterflies. At 1000RPM idle both sides are tight except that the 1st progression hole is just under the plate. These are Dells BTW. The shaft bearings are sealed right?

Thanks for the ideas. I'll be in touch. I hope I can get this worked out before BOR next week end. I would hate to show up in the "other car"

Ron

Update: I hooked the fuel line up and turned the key on to run the fuel pump. gas came through the pump nozzle big time. Only that one. My gues is that the ball was not seating. Float level is good and the needle valve seems to cut off at 5-6 mm (space between the top of float and the top of the chamber.

Plastermaster · Post by **Plastermaster** » Fri May 19, 2006 5:05 pm

O.K. I'm happy again. I took the carb apart and put it back together again and it is working OK now. I will not stress over the gas getting into the oil. After all, My engine was built by the guy that took over 4 hrs to blow an engine that was drained of oil.

Ron