Bad Flywheel?

Hey folks, been a long while since I posted here. After a total overhaul in 2005-07, my 1978 Ski Nautuqe (351 Commander) as been running pretty solid for the most part since then, until now. It all began at the start of the spring, I went to start the motor, and after just a few attempts, the starter would clearly engage and spin, but (apparently) no contact was made with the fly wheel because the motor would not turn over, just the starter (spinning). I figured I had blown the teeth of the starter, and needed a rebuild. So I removed the starter and brought it in for a rebuild (First week of July). The guy at the auto-electric store suggested I try a new, less expensive gear reduction starter (100 bucks) instead of having my 3 year old starter rebuilt for 150. I took him up on the suggestion, and the gear reduction starter worked for about 3 weeks, but each time I hit the starter, I heard a little grinding sound for a half of a second after the motor was started, it sounded like the starter was remaining engaged for that extra half second. I figured it wasn't working right, but it was starting the boat for a little while. Eventually, after a few weeks (maybe a dozen or 20 starts), the starter made the same sound, apparently spinning, but not turning the motor over. So I called the guy up at the starter/auto electric store and told him of the grinding sound and that it didn't work any longer, and he was cool enough to rebuild my original starter at no extra cost. That was 2 weeks ago. Today, after putting on a new fuel pump, I wanted to test it out and see if I could get my carburetor dialed in better. So I put her in the pond in my back yard, and now the starter is just spinning again, apparently not engaging on the flywheel.

The guy at the Auto electric store told me that he thought there was an issue with the fly wheel, because of the way the starter had been marked up. He showed me a round part, near the center of the starter, and pointed out that it was out of round. He suggested that something was somehow pushing the starter out of round, and that I should check my fly wheel. Well that's kind of beyond my mechanical knowledge but I can figure it out with some guidance I'm sure. I have read things that suggest the fly wheel needs to be "re-toothed" by removing it and having a machinist remove the ring around it with teeth and putting a new one on it.. But I would really like some feedback about what you guys feel the problem is. Am I on the right track?

Thanks for the tip, anyone got instructions on removal?

I can't seem to get the motor to budge manually, but I have only tried by hand. Maybe I will try to advance it with some sort of leverage on the main shaft pully?? What is a good way to do that? When I try to turn the belts, nothing moves really. The belts seem to slack on one end, that's all..

78skinautique wrote: I can't seem to get the motor to budge manually, but I have only tried by hand. Maybe I will try to advance it with some sort of leverage on the main shaft pully?? What is a good way to do that? When I try to turn the belts, nothing moves really. The belts seem to slack on one end, that's all..

A socket and ratchet/breaker bar on the crank pulley bolt should easily do the trick.

Thanks for the info on finding one using a 6 cyl manual trans mustang! I finally got the flywheel off last night! Counted them 2 times and came up to 157 both times. But the auto stores I am calling keep telling me that their computers are calling for either a 164 tooth or 180 tooth... I will call and ask about a 157 tooth for a mustang..

Skidim has them for 30 bucks

78skinautique wrote: Yeah, but that's 3 days waiting around for a ring I can get for 10 bucks less and today, not Thursday.

Well then go get it and quit wasting our time!!!

I tryed oxy-Mapp with no success. Finally took it to a local engine builder to have the ring gear pressed on.

I'm not sure if it would save any significant money, but I was able to pound the old ring gear off (cold)in 45 degree increments with a punch. The engine builder only had to press the new gear on, and not remove the old (damaged).

I also bought my 158 tooth ring gear (for a mustang) from a local parts store.