Hi all,
First, the story of this motor...
Person that owned it before me ran it hot 'til it seized... my step-son shot tranny fluid in the cylinders and broke it loose for the guy. Could never get it running right so he gave up and sold the boat and motor to me for $500.
When I received the boat and motor, the lower unit was pulled, the boat was a mess and parts were missing.
Since I started working on this thing a month ago, things have gone fairly well considering what it had gone through before I got it.
Replaced the water pump assembly and impeller. Lost key pin for the impeller was most likely cause of the overheat. It was obvious looking at the shaft that it had been spinning but the impeller had not.
I took the head off to check the cylinder walls, and believing that a new head gasket was in order. Head gasket looked burnt (naturally) but cylinder walls were good, very minor scratching in a couple spots. Put the new head gasket on, did a test run to see if it was worth proceding and all went well. Cracked the head bolts back and re-torqued. Compression check showed 132# top cylinder, 135# bottom cylinder, so head gasket ok.
So now, I take the boat out fishing and it runs great out of the chute... a few minutes to warm up and away she goes with full range of throttle (after major decarb process). I shut her down and troll for 5 hours with the kicker. Done fishing, start up the 50 and let it idle for 5 minutes while putting gear away. She bogs down and dogs... give her some throttle she picks up but misses like crazy for awhile like there's no spark. Sputter around for 5-10 minutes, she finally picks up and runs like she should. When I pull the plugs at home, they're light brown and dry, like they've been steam cleaned, instead of having a light film of oil.
After searching on the subject, it appears that it could be getting water in the cylinders from the exhaust gaskets? With the compression that it has, doesn't that mean the head gasket is ok? Where else besides the exhaust could the water be coming from?
I have already ordered a complete gasket set and am going to break it back down, pull the head, pull the exhaust covers, and do it right. With that kind of compression it's worth hanging on to.
Thoughts?
Thanks folks! I love this forum!
steve
First, the story of this motor...
Person that owned it before me ran it hot 'til it seized... my step-son shot tranny fluid in the cylinders and broke it loose for the guy. Could never get it running right so he gave up and sold the boat and motor to me for $500.
When I received the boat and motor, the lower unit was pulled, the boat was a mess and parts were missing.
Since I started working on this thing a month ago, things have gone fairly well considering what it had gone through before I got it.
Replaced the water pump assembly and impeller. Lost key pin for the impeller was most likely cause of the overheat. It was obvious looking at the shaft that it had been spinning but the impeller had not.
I took the head off to check the cylinder walls, and believing that a new head gasket was in order. Head gasket looked burnt (naturally) but cylinder walls were good, very minor scratching in a couple spots. Put the new head gasket on, did a test run to see if it was worth proceding and all went well. Cracked the head bolts back and re-torqued. Compression check showed 132# top cylinder, 135# bottom cylinder, so head gasket ok.
So now, I take the boat out fishing and it runs great out of the chute... a few minutes to warm up and away she goes with full range of throttle (after major decarb process). I shut her down and troll for 5 hours with the kicker. Done fishing, start up the 50 and let it idle for 5 minutes while putting gear away. She bogs down and dogs... give her some throttle she picks up but misses like crazy for awhile like there's no spark. Sputter around for 5-10 minutes, she finally picks up and runs like she should. When I pull the plugs at home, they're light brown and dry, like they've been steam cleaned, instead of having a light film of oil.
After searching on the subject, it appears that it could be getting water in the cylinders from the exhaust gaskets? With the compression that it has, doesn't that mean the head gasket is ok? Where else besides the exhaust could the water be coming from?
I have already ordered a complete gasket set and am going to break it back down, pull the head, pull the exhaust covers, and do it right. With that kind of compression it's worth hanging on to.
Thoughts?
Thanks folks! I love this forum!
steve
