cost to restore compression?

[sandollar1978]

How much do you guys think it would cost to have my 1979 evinrude 55hp restored compression to 120. I have on top cylender 90lbs and bottom cylender 65lbs? Thanks Again.

 

[walleyehed]

Re: cost to restore compression?

Have you done a decarb recently????

 

[sandollar1978]

Re: cost to restore compression?

Yes, I done a decarb and it help but should I have left over night I just let it sit for about 3 hours then I ran the motor.

 

[walleyehed]

Re: cost to restore compression?

Engine at operating temp when you decarbed??? If so, ok, you may have to try it 2 or 3 times, but seldom does any good to set more than an hour.<br />Tuner only works in a state of vapor when the engine is hot...liquid form does nothing for the most part..<br />BTW, did you ever find any info on that boat??

 

[sandollar1978]

Re: cost to restore compression?

Walleyhead, the first time I did it was with a flush so I probly did't do it right!! So should I get a can and go to the lake the run it to operating temp then poor the can and let it sit over night?? Thanks for you help!! I can't find a information on my 1978 Sandollar!! The only thing I found out is this boat harley exist!!

 

[walleyehed]

Re: cost to restore compression?

Get the type of decarb that comes in a spray can...doing it on the muffs is fine, just let it warm up good before spraying the tuner thru the carbs with the engine running at 1500-1800RPM..<br />It's gonna slow down as you do this and that's normal...just keep spraying in the carbs untill can is empty and kill the engine (shut it off).<br />If the can says "over night" then do so, otherwise a few hours is about all it's good for.<br />If this doesn't bring compression up, a look inside may be in order.<br />I would expect around a 1000 bucks minumum for pistons, rings, and gasket set, with the possibility of needing bearings and some other wear-type items...1500 bucks may not be out of the question depending on what is needed....

 

[sandollar1978]

Re: cost to restore compression?

Great Walleyhead thanks for your help!! I'll try it and let you know!! THANKS AGAIN!!!

 

[walleyehed]

Re: cost to restore compression?

You're welcome Sandollar!!

 

[Chinewalker]

Re: cost to restore compression?

Hi SD,<br /> Assuming your compression gauge is up to par, your compression readings are way below where they should be. As low as they are, I doubt decarboning will bring them back up to spec. Being that your other posts seem to show loagie performance, I am betting it is time for, at minimum, a re-ringing. That would also entail a good honing, new seals, gaskets, etc.<br /> At worst, you're in for a complete rebuild with boring, new pistons, etc. If you do the basic labor yourself and plan on keeping the motor, then it could be worth it. If it's something you're planning on unloading in the near future, dou'd never get your money back out of it... Just a few things to consider...<br />- Scott

 

[steviecops]

Re: cost to restore compression?

I don't know if this is of any help Sandollar, but when I tested the compression on my 1980 Johnson 55, the readings came out at 151 on the top cylinder, and 148 on the bottom, with a screw in type pressure gauge. I thought these readings were too high, so I checked again with a different gauge, one where you push the rubber piece into the plug hole, and as I was alone and couldn't hold it in, the gauge blew out of the plug holes on both cylinders and showed a reading of 110 at time of coming out on both cylinders.

 

[sandollar1978]

Re: cost to restore compression?

Thanks to every one!! I plan on having this outboard for a very long time!! This is my first boat that I owned! You think any body could rebuild the outboard our should I save some money so a perfessional could do it? Thanks again for your help!