tower of power worth it?

[fishdog4449]

hey guys, I've got a mercury inline (in sig) 1976 115. It runs fine, but has a scored upper cylinder @ 115psi versus 135 on the others and I know its not gonna last forever like that. I've been looking for a newer powerhead to put on and I've got the opportunity to buy a '86 90HP with 150psi on all six and the newer type ignition, but needs the carbs cleaned, for 300$. Do ya'll think this is worth it?

 

[fishdog4449]

Re: tower of power worth it?

Also, it should be about the same horsepower because my 76 115 is rated at the powerhead correct?

 

[coolguy147]

Re: tower of power worth it?

thats the first case that i heard that they scored the upper cylinder. next time i suggest running it a bit more then 50:1 to be on the safe side

 

[fishdog4449]

Re: tower of power worth it?

weird isn't it? before i got it running i had to replace the exhaust baffle gaskets thats when I noticed the top piston was scratched up pretty bad. Still at 115 though.

 

[Chris1956]

Re: tower of power worth it?

Fishdog, 115PSI is almost within spec. What caused the scoring? Normally it is overheat or lean mixture. You will need to clean the carbs and replace the impeller, if you want to run it. 50::1 fuel mix is sufficient, but some recommend mid-grade gasoline for those towers.

I do not know if the newer powerhead will bolt up to your midsection. Perhaps Laddies will chime in. if it will bolt up, you might buy the Powerhead and run your motor until it blows up. Power is pretty close, as you had thought.

 

[fishdog4449]

Re: tower of power worth it?

Long story short, I got it last spring and it needed a starter and trigger, rebuilt those and it fired so I rebuild all three carbs and fuel pump and they were pretty gummed up, especially the top one, so I''m guessing the number 1 ran lean at one point, hence the scoring. Impeller was shot too, but after I replaced that it started and ran great and I ran the motor all summer. Then it started getting water in the number 3, but exhaust baffle gaskets fixed that. It worked great, plenty of power and very clean (freshwater only) for a '76which is why I was hesitant to spend money on a different motor.

However, I know it won't last forever like that and I'd rather have a powerhead with good condtion across at 6 at least in reserve in case this one should bite it, which is why I asked.

I also have the opportunity to buy a similar, 70's powerhead with the same type ignition, with even compression for much less. I think I'm gonna go with this one because I can swap my ignition system and carbs over.