Lost # 6 cylinder today

[turbinedoctor]

Yeah I think a rebuild is out of the question but I have a spare parts motor almost identical to this one. I will look into swapping powerheads and going the cheap route for now, but first I want to take this one apart to see what happened inside. If it's something like a weak link that got loose and into the cylinder I may consider buying a used motor and stepping up the HP to around 115 or 150.

[turbinedoctor]

Has anyone had sucess with running 115 hp carbs on a 90 hp inline 6? They are so close to the same engine the only difference I can find is the carbs.

[RidgeRunner]

Sorry to hear obout the tower of power motor. #6 was the one that always went out. I know they don't like running lean. Not positive about the difference in the back drag carbs. Looking it up in my shop manual but it doesn't cover them very well. The main/idle tube jets are different.

Book says 90hp .070main/.092 vent tube
115hp .072 or .074 main/ .092 or .096 vent tube
Depends on serial number.

I rebuilt a 90 inline 6 for a friend back in 1995. The way the pistons go in from the front, all at once, all on the crank as an assembly with very little clearance it really requires the special ring compressing tools and patience. To replace a piston or two is a lot of work because you must remove the crank to take a piston out (no removable cylinder heads)

Whatever you do, do it fast summer is about over. Hope this helps.

[cterrebonne]

Originally Posted by RidgeRunner

Sorry to hear obout the tower of power motor. #6 was the one that always went out. I know they don't like running lean. Not positive about the difference in the back drag carbs. Looking it up in my shop manual but it doesn't cover them very well. The main/idle tube jets are different.

Book says 90hp .070main/.092 vent tube
115hp .072 or .074 main/ .092 or .096 vent tube
Depends on serial number.

I rebuilt a 90 inline 6 for a friend back in 1995. The way the pistons go in from the front, all at once, all on the crank as an assembly with very little clearance it really requires the special ring compressing tools and patience. To replace a piston or two is a lot of work because you must remove the crank to take a piston out (no removable cylinder heads)

Whatever you do, do it fast summer is about over. Hope this helps.

sounds like you need a 4 bolt rebuild.

[kamikaze]

What year is the 115 and what year is the 90. May just be the same motor but from different years for how horsepower was rated (powerhead / propshaft) Believe the older (mid 70's) 90/115 in-line six were the same block/porting and carbs where the only difference. I'd go for it, just make sure you can use/mount your 90 electeonic's ( if newer) on the 115 block if it's older. Your not trying to convert a distributor based ignition system to a CDI switch box are you? Maybe more issues with that than mechnicals associated with swapping the powerheads

Kamikaze

[randlemanboater]

If you want to stick w/ a tower of power, just look for a mid 80's 115 and slap it on there.....they are the earlier 150 with 115 stickers, and can be had for 5 or 6 hundred bucks these days.

[turbinedoctor]

Thanks for all the input guys, I haven't decided what to do yet but one thing for sure, it looks like my summer on the water is over.

The carb swap I was thinking about was to put 115 carbs on my 90 if I get it running again. The block seem to be the same just smaller carbs on the 90.

I finaly got the power head off last night but ran out of time. Will start the tear down soon.

The spare motor I have does the same as mine. on mine it wont go past top dead center on # 6 cylinder and my spare wont go past top dead center on # 3 cylinder. What a kick in the NORTONS.

Am searching ebay for used motors but get scared with no warranty, they all say it runs good, well if I listed mine the day before if crapped out, I could have said it ran good also. Who knows when one will die.

Anybody got an extra 10 grand laying around they dont need, send it my way, daddy needs a new motor.

Turbo