Lost # 6 cylinder today

[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

[turbinedoctor]

If I stepped up from a 90 hp to a 115 hp how much difference do you think I would see and or notice. None, little or alot?

Turbo

[RidgeRunner]

25 more hp. But same displacement. You might need to reprop for a noticable difference. My guess 5mph and a better holeshot.

[turbinedoctor]

Well I must say I am disappointed, all this way and nobody asked for pictures yet, whats going on with you guys, getting slack in your old age?

Well I finaly got it torn down and found whats making all that racket, and I got pictures to boot. It appears that my lower bearing failed, came apart and some of the balls
from the bearing got into the # 6 cylinder.

Pictures are following but I must warn, these pictures are graphic and those with weak stomachs and little children should leave the room.

































This is what a good piston should look like.



This is what a good piston should NOT look like.



That shiny piece in the middle lower half is a piece of the ball from the bearing.

Here is a shot of the cylinder head, not the best picture quality but none the less.



The dark stuff in the spark plug hole is more ball pieces.

And this is what a good cylinder looks like.




Other then a few light scratches on # 6 cylinders wall, which dont show in the pictures, I think it can be honed and reused.