I have a 115 hp in line 6 cylinder. Was wondering if the hp motor could be upped to 150 and what would it take.

Sorry, it is a 1977 Mercury.

basically it could be upped by shaving the heads and some porting along with more carbueration but finding someone to do it and the cost just wouldnt be worth it

basically it could be upped by shaving the heads and some porting along with more carbueration but finding someone to do it and the cost just wouldnt be worth it

wait i just remembered thatengine is a blind bore so head work is out of the question ,maybea tricked exhaust tuner but as i said too exspensive by a newer v6

The 150 is not that reliable. From what I remember every time I had mine rebuilt was because the ports were so large they didn't allow enough room for the rings so eventually, pop.
After two rebuilds I got rid of mine.....or maybe the 6600 rpms I ran it to was the culprit.

I cut my teeth on those in-line 6's. Yes it can be done, No it just ain't worth the trouble or expense. You will have to change the rods, pistons and carbs. Rods are -+ $100 X 6= $600 Pistons are -+ $90 X 6 = $540 Carbs $175-+ X 3 (used)=$525 Gasket set -+$50..... You have just exceded the value of the engine, running, in perfect condition by $1000..... Take your money and Y-2-K into a V-6 Merc. You will be dollars ahead. Just my $0.02.......

thanks for the feedback. I figured that would probably be the case. I have it hanging in my garage as a back up motor to the motor I have on my boat now. I guess I will just leave it there and spin the flywheel and lubricate it to keep it from freezing up.

Thanks again.

Ha Ha that's funny you said that. When I was running my in-line 6-150 Merc on a 16ft Skeeter Wrangler, I also had a 115 hanging in the shop and after 6 rebuilds on the 150, my 115 was also wore out. I swapped engines like every three months and wore out the mounting bolts........live and learn...

I had a 1986 115 Merc. Loved the sound of the engine at wide open throttle .

I took a 150 in-line and ordered 1/8" taller pistons from Wiseco. Drilled out the intake and exhaust ports till only 1/8" left betweeen holes, Rejetted the carbs, bumped the timeing to 32 degrees, gave it some 104 fuel with 50/1 synthetic oil. Promptly screwed the engine to 7500RPM. and twisted the drive shaft smooth off. WOW! what a rush. 15ft Mustang ski boat, 28p clever prop, 109mph.............