1996 johnson 112 spl compression low help

rmc2252

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Jul 6, 2015
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Hey there everyone 3 weeks ago I bought a 19ft wellcraft with a 1996 Johnson 112 spl on it I'm new to boating repair and easy fixs so I don't know much I took the boat out for the first time and it ran great hit the throttle and it tflew threw the water sounded great ran great but when I'd come to an idle it would shut off and I'd have to use the throttle to get it cranked back up so everyone was telling me to get the carb cleaning done and I took it to a local shop and told him what all was going on and he said he would take a look and change everything and try and find out what is going on called me back 3 days later and told me tha. He had checked the compression before he did anything and that the #1 cylinder was at 90 and the one below it was at 130 and the other 2 on the left were at 120 then he told me I needed to get the number one piston replaced is this my only option or is there a possible smaller problem that it could be thanks for the help it is very helpful
 

racerone

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Dec 28, 2013
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Very , very common to break piston rings on these motors.-------But it could be a blown head gasket.-------Pull the head off and have a look first.
 

racerone

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Dec 28, 2013
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No cautions in post # 2 at all.----You remove the 10 bolts and have a look in there.---Nothing to it.
 

rmc2252

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Jul 6, 2015
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Ok thank you it seemed fairly easy just didn't want to start tearing it apart and be in wonderland I'll report back after I take the head off anything specific I need to be looking for ?
 

racerone

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Dec 28, 2013
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As I have said many times---A common failure.----This problem will occur on just about every one of these motors !!!
 

racerone

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Dec 28, 2013
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Many dealers do not rebuild these anymore.---------But if you have the patience / time / manual you can do it yourself.-----------Install a set of O/S pistons from WISECO with different style piston rings.---------Motor will then run properly for years to come.
 

rmc2252

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Jul 6, 2015
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What am I looking forward to as far as parts and tools to do this job a ballpark price range
 

rmc2252

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Jul 6, 2015
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So if I bought the repair manual will it show me where everything goes and and how to replace it all?
 

Bosunsmate

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So if I bought the repair manual will it show me where everything goes and and how to replace it all?


Yes sure, all you need otherwise is general tools- sockets spanners etc and a torque wrench is essential at least up to 100foot pounds.
You will also need a flywheel puller which are about $30 but then again most boat shops will pull the flywheel off for a few bucks
 

rmc2252

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Jul 6, 2015
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Alright thanks guys I got a repair manual from marineengines.com on the way I was hoping to get a early start and get the power head off anyone know the bolts I need to remove or a video to show me looks of the cylinder wall I'm gonna have to get it honed or bored
 
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