60hp surging

[jimmyz1]

Hello

I have a '87 60hp merc that has ran fine the first 4 trips this year. It started easy yesterday and ran fine up river to where I fish. When done fishing after 4 hours, it starts fine. When I gave it throttle, it hesitated a bit then got up on plane and seemed fine for maybe a minute. Then it started to surge. It still kept speed and never came off plane. I was going 26-27mph. Rpm's where about 5000. I think my speed should have been closer to 29-30mph where the rpms and throttle were at. I put a little pressure on the primer bulb and when I did that it made it worse. Like it's getting to much fuel.

Get back close to ramp, I shut throttle down, ran rough. When I gave it throttle it hesitated way to long then finally shot up, but surging the whole time.

The only thing I did do different is use a different 2 cycle brand for the first time. I used quicksilver, I normally use pennzoil. The oil injection was disconnected by previous owner, so I mix. I only topped off the 6gal. tank with 2 gallons of gas and correct amount of oil.

Sorry if I rambled. Is there any easy thing I can look for before taking it to the shop.

Thanks.

 

[jimmyz1]

Re: 60hp surging

Well more info. I pulled the plugs. Cylinders 2 and 3 plugs look great. cylinder one plug fouled out. Ceramic is very black. Other 2 are white with a little brownish tint. So I guess i will buy new plug and see if it fouls it out and if it does, It's off to the shop.

 

[jimmyz1]

Re: 60hp surging

Well, after taking to mechanic, news not good. He says he checked a bunch of stuff. Compression is all 3 cylinders was good. However, he said after checking the other stuff he did a leak down test on the cylinders, and #2 is leaking at about 15%, #1 10%, I think and #3 5%. When the motor starts now it's only running on 1 cylinder.

He is not a fan of mercs and when I bought the boat last year and told him what was on it, he sounded surprised there was a '87 60hp 3cylinder still running. His options for me were to find another motor. What would be entailed in making this one run good again? Re-build the power head? He didn't give me an estimate, but he doen'st think it would be worth it.

I didn't get any replies yet. Could anyone give me advice on if this all sounds accurate.

Thank you.

 

[jimmyz1]

Re: 60hp surging

WOW! Not one reply. Did I do something wrong here? Do I have some boating scarlet letter on me? My post aren't written in Chinese, are they?

 

[AEROCOOK]

Re: 60hp surging

Okay, Ill bite.
Sounds like he just doesnt want to work on your motor.
If the compression is good (and even) on all cylinders then its unlikely that the problem is mechanical in nature.
If it were mine, I would check for good spark and if that checks out okay I would suspect dirty carbs or some sort of fuel delivery issue. (the vent on your fuel tank is open right??)
Spark + fuel = combustion and it sounds like you dont have combustion.
I also find it odd that you originally found 1 plug out of 3 fouled but now the motor is running on only 1 cylinder, seems the problem is getting worse?
As for the technician's negative remarks about this type of engine and Mercs in general I think outboard opinions are a lot like the old Ford vs Chevy debate.... You will never convince a diehard Chevy guy that Fords are just as good or vice versa.
It's Just his opinion. (IMHO)