Fuel from rear manifold drain??

[PeterB]

After an engine rebuild and being in storage for many years, I finally started the car and tuned the engine last month for the first time. It ran and sounded great and everything looked good compared to the workshop manual and forum standards. After running at idle a few times and a couple of short yard drives it seems gas comes from the rear manifold drain after I shut the car off especially if it hasn't run that long. Any ideas where to start looking?

 

[Patrick67BJ8]

After an engine rebuild and being in storage for many years, I finally started the car and tuned the engine last month for the first time. It ran and sounded great and everything looked good compared to the workshop manual and forum standards. After running at idle a few times and a couple of short yard drives it seems gas comes from the rear manifold drain after I shut the car off especially if it hasn't run that long. Any ideas where to start looking?

If your running HD6 carbs the problem is more likely the Jet/diapram. They harden up when not in use much and crack.

 

[BJ8Healeys]

Pat, if the jet diaphragm is leaking, you'd see gas dripping from the bottom of the carb jet housing. Diaphragms are used in HD-<span style="text-decoration: underline">8</span> carbs.

Gas dripping from the front or rear drain tubes indicates raw fuel in the manifold. This can be normal if the engine is cold and hard to start and cranking attempts are prolonged, or if the engine is shut down before it warms up completely. I think it (rear tube) could also indicate flooding of the rear carb, although I've only seen it happen during cold cranking. If it's happening with the engine warm, I would check the jet adjustment.

 

[Keoke]

Hi , maybe the choke setting is still a bit rich

 

[Randy Forbes]

HD-6 (H for horizontal / D for diaphragm?) carbs also have diaphragms, and they do indeed harden and crack after being exposed to gasoline and then left to dry up.

Depending on your dexterity, these can be replaced without removing the entire carb...

 

[BJ8Healeys]

HD-6 (H for horizontal / D for diaphragm?) carbs also have diaphragms, and they do indeed harden and crack after being exposed to gasoline and then left to dry up.

Depending on your dexterity, these can be replaced without removing the entire carb...

Thanks for the correction, Randy, and sorry, Patrick. I thought "HD6" was a typo for HS6. I'm only familiar with the carbs on a BJ7 and BJ8.
I don't know about the other models, but removing the carbs on a BJ8 isn't my favorite job. I think I would like even less, though, trying to change the diaphragm without removing the carbs first, if that is even possible.

 

[PeterB]

Thanks guys, it is a BJ7 with HS6 carbs so I don't believe it has diaphragms