No power, can't get above 3k RPM's on 80hp Merc

jdfmtx · Aug 31, 2006

I have a 1986 Mercury 80hp outboard (3 cyl) that hasn't been used for about 2 years (worked ok back then). After spray cleaning the carbs, putting new gas in the tank with new fuel filter it starts and seems to run ok on land (can get above 4200 rpms). But when I ran it on the lake under load it doesn't seem to have a lot of power and I can't get above 3k rpm's. Idles and runs ok just no power. Any ideas?

ricksrster · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

you can take the carbs apart to clean/rebuild them, rebuild fuel pump, do a de-carb and check the high speed windings on you stator.

jdfmtx · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

I have already spray cleaned the carbs although they showed no signs of carbon when I first checked them. Also ran thru some carb cleaner in the high octane gas that we put in the tank. While we were running on the lake I tried pumping the gas line bulb, no difference. I will have to check on the stator since I didn't know there were two windings. tks. Jim

ricksrster · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

Can't find the info on a 1986 80hp

jdfmtx · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

It's a model 1080727 if that helps. Do you know of any good web links that would show me how to check the high speed windings on the stator? Most of the ones that I found so far have been pretty generic. tks!

ricksrster · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

What's the serial number?

jdfmtx · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

0B145953 oil injected 80

Chris1956 · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

Try this link. Paste it into your browser's address space. It has the 4 cylinder ADI troubleshooting guide.

jdfmtx · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

Tks for the link.
One more little twist to this is that if I put the boat in reverse and "floor it" I can get up to 4k rpm's momentarily (boat doesn't like to go in reverse that fast with the prop). But can't do this in forward. Perplexes me.

roger3645 · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

Dirty carbs. You need to take the carbs off/apart and clean them. The spray can just won't do the job.

jdfmtx · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

Ok, thanks for the info! I'll see what I can do about the carbs.

dlandon · Aug 31, 2006

Re: No power, can't get above 3k RPM's on 80hp Merc

You're problem is common after a motor has sat for a while. When the fuel pump diaphram starts to harden up, it has a harder time delivering fuel while under load. I'd rebuild the pump. Crud builds up in the fuel bowl after sitting for extended periods of time, so rebuilding them would be a good idea. Spraying carb cleaner can't clean the carbs the way they should. Good luck.

No power, can't get above 3k RPM's on 80hp Merc

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