Lost Compression - Mercury 115 - Inline 6

[mikesboat]

I have a Mercury 115hp - Inline 6. Just found out that the #1 cylinder has lost compression -tests at 20lbs - the other 5 cylinders average about 120lbs. Shop is telling me to either rebuild or change power heads. Any other suggestions? Will it damage the motor to continue using it as is? Where's a good place to search for power heads or motors?

 

[Coloradolakeboy]

Re: Lost Compression - Mercury 115 - Inline 6

I'll bump your thread, maybe someone here can direct you to a reputable supplier or provide better advice.. I would think that by the continuance of running your motor, it would rule out a rebuild on her.. So, if it is a good rebuildable powerhead, I'd shut her down.

 

[Droll]

Re: Lost Compression - Mercury 115 - Inline 6

Whatever you do... drop the lower unit and replace the impeller ( #1 first to when bad ), second ... DO NOT RUN the engine until the problem is fixed, further use WILL destroy what's left!!

If you decide to rebuild the powerhead
New piston ? $ 100.-
Gasket kit ? $ 90.-
Some new bearings ?? $150
+ some $

= not that expensive...




Arne Kjetil

 

[wedge542]

Re: Lost Compression - Mercury 115 - Inline 6

my 115 got sick so im building it now,priced reman refurbed rebuilt powerheads, all parts needed to build can be found on this site by 2-3 good guys,,,mines comeing from faztbullet here,,,get a good book and learn something new or get with him if you think its more than youd wanta tackle or have tools for,,but if you do it yourself just do searches here,youll find about any info youll ever need to diag,repair,replace..jmo anyway.

 

[mikesboat]

Re: Lost Compression - Mercury 115 - Inline 6

Thanks for the notes. I have it at a mechanic right now since I didn't know what the problem was, he tested the compression. He's saying that if we are to rebuild it, we might as well have all 6 cylinders/pistons rebuilt. He also said that he'd have to send it to the machine shop to have it bored out. A replacement power head is going to cost $2,500-$3,000 with labor.

 

[mikesboat]

Re: Lost Compression - Mercury 115 - Inline 6

Droll - looking at some of your projects, you seem to be more mechanical than i can even imagine being. I am fairly mechanical, & with some advice & direction think that i could do this. What is the best way to get started? do you have step-by-steps instructions for replacing the piston? Should i replace all 6 or just the bad 1?