lower crankshaft seals

[HAS]

1985 50hp.4cyl. 2carb.
when I got this engine in 09 the compression was 130, 130,125 and 100 on no.4,
I replaced the lower crank seals then, now the compression on no. 4 is down to 85.
Are the seals damaged by the exhaust heat and pressure combined with the water?
If so is there a way to keep the exhaust and water away from the seals? I would
like to overhaul this engine next winter and would like to find a more permanent
fix then replacing the seals every other year like the water pump.
I hope you dont think this is one of those dumb questions.
THANKS TO ALL..........HAS

 

[chum1]

Re: lower crankshaft seals

First off i would determine if water was entering lower cyl. by spark plug condition (super clean means water) if there was water and that was causing the problems it could also be the water jacket gasket or other possible problem other then bad lower seals, seals usually last a long long time if put in correctly.

 

[HAS]

Re: lower crankshaft seals

Chum1 last novenber had a water problem with no.1 and no.3. I replaced the exhaust
plate and have not had any more water problems. Looking in the spark plug holes
all the pistons have carbon on them. I know when i replaced the crank seals it did
nothing for the damage already done. I have seen what bad seals can do if not
found in time. Thanks.....has

 

[chum1]

Re: lower crankshaft seals

Bummer on #4, you might try some some easy things first,stuck ring perhaps? I would put wd 40 or some mouse milk in that cyl. and let it sit, might get lucky.