Possible water intrusion?

[Kailofsouls]

Ok I'm replacing my fuel lines and pumps in a 73 1150 in-line 6. Pulled the upper pump and there is droplets of water behind the diaphragm. I assume that is not normal. What could cause this? The bottom pump is dry behind it and my plugs look normal not washed clean or anything. Compression is good as well. Just need to know before I try putting her on the water again. Thanks in advance.

 

[Chris1956]

Water can get into the crankcase two ways. First is via bad lower crankshaft seals. This affects the lower cylinder or two, and doesn't look to be your issue.

The second way water can get into the crankcase is via a leaking exhaust baffle or inner water jacket. That can affect any or all cylinders.

I would run the motor and then check the spark plugs for water or "steam cleaning". If you see that, you will need to decide if you want to fix it.

 

[Kailofsouls]

I've been running the motor all summer,and my plugs are not ''washed'' they look completely normal little bit of oil/gas feel and smell slightly bronzed thats it. It's only the upper pump I think it's linked to cylinders 3 and 4 lower pump off of 5 and 6 correct? All 6 of my plugs look identical when you take them out. Would the exhaust gasket cause that but not put water into the cylinders?

 

[Chris1956]

If she is running well, and the spark plugs all look the same, perhaps you are chasing ghosts. Is it possible the fuel pumps are leaking fuel into the motor?

If you were to try to replace the exhaust covers, baffles and gaskets, the likelihood of breaking their mounting bolts is great. You will have a world of trouble then.

I would run it until you have an issue.

 

[Kailofsouls]

Ok thanks for the info. She does run great at idle and through mid throttle, but bogs out before she planes out. Thinking it is a fuel issue. Got black sludge in the carb screens. Cleaned carbs tank and replaced fuel lines to motor. Still got more sludge on screens so replacing internal fuel lines.

 

[Chris1956]

Doesn't a '73 have banjo filters under the carb covers?

Make sure float height is dead on. Those sidebowl carbs likely empty when you give it fast throttle, so you want as much fuel in 'em as possible.

 

[Kailofsouls]

It has cylinder shaped metal screens underneath a cap on top of the bowl cover. That's where the black sludge is collecting. I'll double check the float hights tomorrow. Thanks

 

[Kailofsouls]

Ok new fuel lines are in with pumps and carbs are recleaned, and i checked the floats and arms for inspec. Got her started on the muffs now to hit the water and try her out. Hopefully I'll see her plane and hit higher than 4700 rpms. I'll post an update when I do it this weekend.