1977 15hp evinrude tune up?

[qb100]

Experts,

I have a wonderfull running 1977 rude 15704M that my dad bought when I was 4. Starts great, runs great. However, the 14ft aluminum boat we have had for years no longer gets up on plane and just boggs through the water. I am looking for some suggestions what I can do to get the motor to run at its peak. I just changed plugs on it. Do you think it just needs a tune up or are there other items that need to be done to an engine this age?

With the cost of new engines I can't afford to upgrade to a 20 or 25 so I have to get some more life out of this one.

Any tips or suggestions would be appreciated

Thanks for any help!
QB100

 

[tashasdaddy]

Re: 1977 15hp evinrude tune up?

welcome to iboats, is this just an open fishing boat. if so that 15 should push it very well. i had a 1955 15 on a 14' that would run 25 mph. do you have spark on both cylinders, will it jump 1/2 inch. check your compression and post the numbers. when was the carb last cleaned, and rebuilt. when was the impeller last changed?

 

[qb100]

Re: 1977 15hp evinrude tune up?

It is an open fishing boat and it used to move pretty good. When I changed out the plugs the old ones looked like they were burning good, no buildup or redisue. How do you check compression on this? What tool is needed? As far as I know we never had anything rebuilt. I changed out the little rubber water impeller a bout 5 years ago and the cooling return is working fine. I'm guessing I need to get the repair manual and do some basics on it or take it to my local shop.

I am hoping to get some opinions on possible causes before taking it in rather than going blind and getting talked into more work than it needs. What manual would you recomend I get for this motor?

Thanks again for the welcome and for any advice

 

[HighTrim]

Re: 1977 15hp evinrude tune up?

Try reading these stickys and let us know what you find...

http://forums.iboats.com/showthread.php?t=188767

http://forums.iboats.com/showthread.php?t=158086

 

[qb100]

Re: 1977 15hp evinrude tune up?

Thanks for the links I'll check them out and see what i can find.