Evinrude 1990 200HP

[chavonbravo]

Hello all, first off this site is great, I've rarely posted as all questions have already been answered, and I'm sure mines must have been asked before, but I couldn't find it.<br />Anyways, I recently purchased this outboard, and I did a compression check on it and even ran the engine before buying, it was great. It had compression of 88-90psi on all 6 cylinders, which is normal for a looper model. When I got the engine on my boat, I ran it again, with a flush device, and it started right up, no problems. The idle was great. I turned on and off quite easily there, so I decided to take it out on the lake right then and there. In the lake, it was a different story. It was difficult to turn on. It would only turn on when the throttle was almost all the way open, and as soon as I tried to bring it to an idle, would shut off. Plugs were fouling a bit too. Afterwards, I did a compression check on it, with the same gauge I had used before, and the compression was around 70psi on all 6. How could it have dropped 20psi? And so evenly? I'm thinking maybe the guy that sold it to me used 24:1 mix for better compression? I used 50:1. Is my engine useless? I mean, it ran perfect without a hitch for like 10 minutes with flush device. Any help would be appreciated, thanks!

 

[Silvertip]

Re: Evinrude 1990 200HP

I don't like to judge people but sometimes people just take advantage of others. That said, did you do the compression check before you test ran the engine or after? If you checked compression before starting it, the owner may have sensed you were going to do this and oiled the cylinders to bring compression up. After running it of course the oil burned off and compression returned to its lower value. Low compression is probably why its hard to start. Also, since there is no load on the engine while on the flush device there is no way you could have known about the performance issue. If it were mine, I would pull the heads and inspect the cylinders for scoring and any signs of piston damage. I suspect you simply have a high-hour motor that is in need of an overhaul. With even compression, I doubt there is any serious internal damage. Perhaps rings will bring compression back to normal values and you will have a great engine. Only inspection will determine that. Good luck.

 

[Walker]

Re: Evinrude 1990 200HP

I wouldn't jump to any conclusions just yet. The reason it runs different in the water is because of backpressure on the exhaust. Me personally, I'd talk to the guy you bought it from and express your concerns. Have him agree to letting you take it to a mechanic to get it checked out and if there is a problem you can back out of the deal. The fact that all the cylinder compressions are even makes me think the engine is sound. A good carb cleaning and then a de-carb job sounds like its in order for that motor.

 

[chavonbravo]

Re: Evinrude 1990 200HP

Thanks for the replies. The initial compression test was done before running the engine. I think I'll try the carb cleaning and decarb first to see if that works, if not I'll pull heads off to see what's up. Just wondering, if I can't make it turn on again, how can I do the decarb? Don't you have to run the engine for like 15 minutes with decarb in your mix? Is there a way around this?

 

[R.Johnson]

Re: Evinrude 1990 200HP

There is a simple solution! Pull the cylinder heads' then you know.