Author Topic: PD42B Leaking oil??  (Read 539 times)

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Offline Radski

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PD42B Leaking oil??
« on: September 17, 2019, 07:45:06 AM »
hey guys,

got the bike on a few test rides and all seems to be outstanding BUT...I noticed a tiny bit of liquid on top of my starter cover and slightly on the drain line from carb #2. I looked closer and it does not smell like gas. It in fact feels and smells like an oil.

I've looked at the connection between the carb boot and the carb plate and its bone dry. This is only happening on carb 2 where my accelerator pump is. Now I know no oil goes through the carb....right? I havent taken them off the bike to inspect but could it be the link between the carb plate and the carb itself? I havent riden in a couple days but have gone out to start it...well bc I finally have it going solid and love hearing it. lol

But went out this morning to find a very tiny bit again on the drain line from carb 2 where it lays on the starter cover and the bottom of the float seems to be damp. But again it doesnt smell like fuel...but in fact like oil.

A friend of mine said that the accelerator could have held gas while it was off the bike for two months, but I assumed that when I was cleaning them and setting the float heights that it would have dried out?

Anyway and insight would be great. Like I said I havent taken them off to inspect but why oil??
1976/1977 Honda Cb750 "Odzilla"

Offline Bankerdanny

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Re: PD42B Leaking oil??
« Reply #1 on: September 17, 2019, 08:15:55 AM »
Any oil finding its way onto the carb is coming from someplace else. I would guess from the crankcase vent at the top rear of the valve cover or the line attached to it.
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Offline Radski

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Re: PD42B Leaking oil??
« Reply #2 on: September 17, 2019, 08:21:07 AM »
Any oil finding its way onto the carb is coming from someplace else. I would guess from the crankcase vent at the top rear of the valve cover or the line attached to it.

yeah so I've got a breather filter on the crankcase filter and although I havent pulled it off to check it appears dry. Tops of carbs are all dry... I'm literally stumped. I may have to take them off to inspect further. Just wondering why oil.
1976/1977 Honda Cb750 "Odzilla"

Offline Radski

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Re: PD42B Leaking oil??
« Reply #3 on: September 17, 2019, 08:24:52 AM »
also before anyone else says...the valve cover is fine. Dry all the way around.
1976/1977 Honda Cb750 "Odzilla"

Offline Don R

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Re: PD42B Leaking oil??
« Reply #4 on: September 19, 2019, 01:43:40 PM »
So you have a filter breather on the valve cover and are mystified where a drop of oil under it could come from?
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Offline DaveBarbier

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PD42B Leaking oil??
« Reply #5 on: September 19, 2019, 02:08:41 PM »
When I had a filter on the breather of my 550 it dripped oil all over the #2&3 carb boots and back of the motor. I removed it and put a hose on. Much cleaner.

Offline Radski

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Re: PD42B Leaking oil??
« Reply #6 on: September 23, 2019, 04:03:10 PM »
So you have a filter breather on the valve cover and are mystified where a drop of oil under it could come from?

yes tops of carbs are dry and clean. It def gas not oil...so now I just need to find where its coming from.
its the carb that has the accelerator and is def coming from above the float bowl line.
1976/1977 Honda Cb750 "Odzilla"