Questions before I buy a used motor

[packman35]

I am looking at a used boat with a 115 hp Evinrude. The boat is a 1993 so I assume the motor is the same vintage. That unfortunately is all I have on it.

The dealer says they did a compression test and measured 85/85/80/75. He said his mechanic said that was fine and within Evinrude's specs. Does this sound right? I thought the goal was >100.

Also, he said the gear lube was a little "burnt" so they changed it. He said that was also "not a big deal".

I am trying to sift through dealer BS vs. reality as I know NOTHING about these motors.

Any help/opinions is appreciated.

 

[iwombat]

Re: Questions before I buy a used motor

In general, there is no real compression spec for psi.

Compression test is pretty low, that can be attributed to a gauge. But, the real kicker is that they're NOT within 10% of each other. That's out of spec according to the factory.

 

[tashasdaddy]

Re: Questions before I buy a used motor

i would like to see higher #'s, but every compression gauge reads differently. the main thing is they are within 10% of each other. doing a decarb on the motor may bring the numbers up. i think i would want to bring in another gauge and watch them do the test.

 

[HighTrim]

Re: Questions before I buy a used motor

Having the gear lube a dark black does indicate that it is a bit burnt, and should have been changed a bit sooner. Having it come out milky white is the bad scenario, meaning that there is water intrusion into the lower unit, and that is not good.

Those numbers are not real bad, It is quite possible that the last compression numbers listed are for the bottom cylinders, and a decarb may help even them out some. As IW stated, the numbers vary on gauge used, along with a few other factors. The main thing is that they are even.

Regarding the boat, how does it check out? Did you get a survey for it?

 

[packman35]

Re: Questions before I buy a used motor

Thanks guys for the replies. My post regarding the boat itself is in the main forum:

http://forums.iboats.com/showthread.php?t=287412

From what I gather from the dealer, he is selling it consignment. The owner has health problems, hence the sale. The dealer said he sold the owner the boat 1.5 years ago and the pulled the records from then and the numbers are the same as when they sold it to him.

According to Boattrader, it has been listed for 3 months which probably means it has been sitting around that long without running. Could this be why the compression is low?

If decarbing the engine doesn't bring the compression up (or more in line cylinder to cylinder), what does that mean? New powerhead ($$$) or something that I could do myself to "refurbish" the engine?

Sorry for all the questions. I know nothing about OB engines.

 

[iwombat]

Re: Questions before I buy a used motor

Honestly, you'd think the dealer would have already done a decarb to get max resale out of it. That, and use the most favorable compression gauge he could find.

If it were me, I'd be considering the motor a project and if it weren't basically free I'd be looking for a better deal.

 

[jonesg]

Re: Questions before I buy a used motor

Offer $1800.
AFTER checking the transom and stringers.

You could easily drop $1000 into the engine.