merc 140 hp reed valve?

Hello

I have a 1980 merc 140 that came on the boat I bought last year , I was told that it runs but only up to 2000 rpm then loses power. I posted the question what the problem could be and was told to do a compression test and it could likely be a high speed stator. I have'nt done anything with the motor except store it over winter with storage spray and fuel stabilizer in the tank.I now have contacted the previous owner and he now states a mechanic diagnosed it as a blown reed valve and he could'nt recall which cylinder. This motor was fresh water only and used this only 2 weeks a year until 2008. It looks mint inside and out. The question is what would be the best way to approach this issue now. He said that it would have to be pulled apart to see what damage has been done. This means taking it to a shop of course. What would one expect for hours of labour and any likely parts it will need.I would like to revive this motor but not sure if it will be worth it now. your advice like always is greatly appreciated.

Re: merc 140 hp reed valve?

a rebuilt power head goes for around 2000.00 a new 140 hp motor around 14,000.00 . a broken reed plate can do enough damage to warrant a rebuild - the previous owner should have told you about that before he sold it - i'd ask for my money back .

Re: merc 140 hp reed valve?

Thanks verado7 for your reply yes not a good situation.

Re: merc 140 hp reed valve?

The reed valves on that motor are real robust. it would be surprizing if one was bad.

Take a compression test. If all cylinders are 100PSI+ and within 10% of each other, the motor mechanical condition is likely fine. Now get on the CDI Electronics web site and pull down the troubleshooting test for the stator and see if the high speed windings ohm out correctly.

Post back your findings.