boat motor compression

[jasongp99]

I am thinking of buying a used boat from my local dealer. The boat is nice and it is cheap. They will not warranty the motor because it didn't test to their standards. They claim it has a 5% loss in compression. It's a 1987 50 hp Evinrude. Is this a red flag or is this normal on an older motor? I don't water ski and am not one to "fly" across a lake. So if it's normal usage and basic trolling will it be fine?

[Surface Tension]

You'd like to have all cylinders within 10 percent of each other.
A dealer that tells you 5 percent tolerance isn't within their standards would be a red flag toward some other undisclosed problem that motor may have.

[jasongp99]

A friend of mine said any older boat motor will have a loss in compression, due to it being used over time and just through fatigue. Not sure if I trust him.

[Valv]

ST is correct, 10% is acceptable.
I suspect too something else wrong with motor.

Even Evinrude/Johnson or Mercury factory manuals describe 10% as common.

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Val Vignati

www.kvesurplus.com
[email protected]

[mnrstrider]

Keep looking is my suggestion, Trust me I've had boat problems I've spendt countless hours reading researching, taking stuff apart, putting it back together again and again, and again, in my driveway, hours wasted not fishing, and certainly not having fun either. One problem cost me about 9K to fix , but since I've bought my new boat, I've refound my old hobby, fishing. Your money would be best spend on a quality motor. If I had 2K to spend I buy a good motor and a cheap boat, and day. I'd shorefish before I'd take my old boat back.

[wastewaterguru]

If it truly was within the 10% described in the manuals.........they would likely warranty it for at least some period of time.

The fact that they won't would certainly raise a red flag to me.

Tell them you want to take the motor to a third party mechanic for a once over and get a professional opinion. It may cost you a little to have another shop look it over, but the piece of mind would be nice.......

I don't think it would be worth the risk to buy it without a warranty or a checkover unless they are practically giving it away.