Tri Power leaking fuel into engine
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Joined: Apr 2020
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From: Boca Raton, FL
Tri Power leaking fuel into engine
My L68 is leaking fuel from the outboard carbs into the engine causing a hot start problem. It's leaking through the transfer slots and the hole under the throttle blades (where the circle of fuel is in the pic), which are connected. The carbs leaks the same way on a bench as they do in the car, so its not syphoning, vapor lock, etc. It seems to be a gasket issue. I got new metering sealing plates as the old were pitted and they came with very thin gaskets to seal to the metering plate. With the new plates and gaskets it still leaks on a bench. Could a thicker gasket help?
I'm looking around for other thicker sealing plate gaskets but not much out there!
I checked the surfaces for warpage but didn't see any warpage.
Thanks
Mike
Last edited by Monaco400HP; Jan 19, 2025 at 09:53 PM.
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My L68 is leaking fuel from the outboard carbs into the engine causing a hot start problem. It's leaking through the transfer slots and the hole under the throttle blades (where the circle of fuel is in the pic), which are connected. The carbs leaks the same way on a bench as they do in the car, so its not syphoning, vapor lock, etc. It seems to be a gasket issue. I got new metering sealing plates as the old were pitted and they came with very thin gaskets to seal to the metering plate. With the new plates and gaskets it still leaks on a bench. Could a thicker gasket help?
I'm looking around for other thicker sealing plate gaskets but not much out there!
I checked the surfaces for warpage but didn't see any warpage.
Thanks
Mike
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Joined: May 2006
Posts: 18,692
Likes: 2,572
My L68 is leaking fuel from the outboard carbs into the engine causing a hot start problem. It's leaking through the transfer slots and the hole under the throttle blades (where the circle of fuel is in the pic), which are connected. The carbs leaks the same way on a bench as they do in the car, so its not syphoning, vapor lock, etc. It seems to be a gasket issue. I got new metering sealing plates as the old were pitted and they came with very thin gaskets to seal to the metering plate. With the new plates and gaskets it still leaks on a bench. Could a thicker gasket help?
I'm looking around for other thicker sealing plate gaskets but not much out there!
I checked the surfaces for warpage but didn't see any warpage.
Thanks
Mike
https://www.ebay.com/itm/165605666123
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Joined: Apr 2020
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From: Boca Raton, FL
I used the blue gaskets but i also used the older brown holley gaskets for the bench test. Same results.
The sealing plate gaskets are different from the regular metering plate gaskets as they are much thinner.
Just to be clear - there is no metering block, just a metering plate, sealing plate, and gaskets. This is a Tri Power.
Thanks!
The sealing plate gaskets are different from the regular metering plate gaskets as they are much thinner.
Just to be clear - there is no metering block, just a metering plate, sealing plate, and gaskets. This is a Tri Power.
Thanks!
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Joined: Apr 2020
Posts: 56
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From: Boca Raton, FL
This is the paper thin gasket with the sealing plate from Holley. Some say you don't even need this sealing plate at all, just attach the metering plate right to the blue gasket and go. Thoughts?
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Are you saying with the engine running the fuel level, not the float itself, is at the bottom of the sight plug. You can't set the float level accurately on a bench.
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Last edited by MelWff; Jan 19, 2025 at 11:18 PM.
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YOu need to strip the plate off the front of the carb and use a straight edge and a flashilight to see the warp. The rear carbs do not use the transition slot or the idle passage that you describe your leak as comiing from. If you go to my thread I describe a lot of the warpage you are talking about. Its a long thread and I modify my carbs extensively but your issues are common to everyones tripowers. THe front face and bottom of the carbs warp as well as the intake itself.
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Joined: Apr 2020
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From: Boca Raton, FL
Both outboard carbs have the slots and the hole directly beneath the throttle blades.
I checked the surfaces with a straight edge - there may be the problem. There is a very slight amount of light that shows on the edges.
I checked the surfaces with a straight edge - there may be the problem. There is a very slight amount of light that shows on the edges.