73 4 hp seahorse what I found under the flywheel

[danray35e]

Well I popped the flywheel off and the coils look great. New in fact if I had to guess. I haven't checked the points yet cause I wanted to find the source of the scraping sound.

I was going to take pic but the battery in my camera is dead.

The underside of the flywheel has scrape marks on it where the magnet is.

What it was scraping on.....

The iron core of the coils sits on little metal pegs those little pegs have about a 16th of an inch worn away on them where it was scraping.

Also the parts of the coil that the magnet passes by have scrape marks on them.

My first two guesses are
1 The flywheel is somehow warped.
or
2 The needle Bearings on the crank shaft are worn and maybe letting the flywheel move from side to side because of wear?

Opinions wanted please

 

[JSGOLD]

Re: 73 4 hp seahorse what I found under the flywheel

My guess would be wrongly installed coils..... On mine it is possible to have them rub if not excactly right....

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

I thought that as well, however if that were the case, I would think that only the coils would be scraped not the metal parts of the base the coils are mounted on. Bare in mind it is only scraping on one side of the flywheel where the magnet is embedded in the metal. So with each pass it is not only scraping the coil but also the metal tabs (which are molded into the baseplate) The coils bolt down to these tabs. So if it were just a matter of the coils being installed incorrectly it would only be hitting the coils. Looking back there also seemed to be a sort of knocking sound which in my mind would be indicative of slop in the crankshaft.

 

[boobie]

Re: 73 4 hp seahorse what I found under the flywheel

How much side play do you have in the mag plate to which the coils are mounted to have ? You could also have one bad upper main bearing.

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

I assume when you say side play you mean is there any slop or movement of the mounting plate from side to side. Well I went out and tried to move the mounting plate. As far as I can tell there is no side play. I simply turns as it should to without any play.

However I held the engine and pushed and pulled on the shaft the flywheel mounts to. I felt it give a little. Its a very small amount of movement, but I suppose under power that small movement would magnify into an oscillation capable of producing a movement capable of causing it to scrape. I am really leaning on thinking that it is the upper bearing.

I'm guessing there should be no noticeable side to side movement on the crank shaft at all?

 

[jay_merrill]

Re: 73 4 hp seahorse what I found under the flywheel

It is possible for the coils to hit the inside of the flywheel, if they are not mounted on the bases that are molded into the armature plate correctly - there is enough "play" in them to do that. You must mount the coils so they don't stick out beyond the outer edges to the mounts at all.



???

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

but its hitting the posts the coils are mounted too as well

 

[soundchaser]

Re: 73 4 hp seahorse what I found under the flywheel

Solution......

Put the engine back together, Let the post scrape. Run it while you're finding another $100 4hp motor, when you find the new 4hp still run this one until it dies and then call it a parts motor for the new one. Don't spend $500 in thought about this $100 motor.

 

[jay_merrill]

Re: 73 4 hp seahorse what I found under the flywheel

I reread your posts and a couple of things come to mind.

The knocking is probably from the post/coil hitting the inside of the flywheel. If the crank is "sloppy," you might be able to feel some side to side movement if you try to move it by hand. If the contact is in the area of the magnet only, the magnet could be coming loose. I suspect, however, if that were the case, the constant contact would have knocked it out already.

I would also check the armature plate, to see if there is any side to side movement. It is held in place via four screws that fasten it to a retaining ring. Two of the screws go down through the plate near the points and the other two go through the ignition coil laminations. You will notice that the coils have three screws each - two with straight slot heads and one with a philips type head. The latter are the screws that go into the retaining ring.

Check to make sure that all four of the screws that I mentioned are tight and that the armature plate is secure. If it is, my only other thought is that the needle bearing assembly at the top of the crank/powehead casing is bad and you have play in the crankshaft.



???

 

[kbait]

Re: 73 4 hp seahorse what I found under the flywheel

You mentioned that the mounting site that the coils sit on is rubbing on the magnet. They are, in fact, machined down a bit, and that's where you line up the coils. Are you assuming that the flywheel magnet is rubbing there, when it may just look like it?? If you can send a pic, it could be verified. For now, loosen the coils and mount them even with that machined edge and put the flywheel on and hand spin it to see if they'll clear. If they don't rub, torque the flywheel down and fire it up.

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

I wondered if the part was machined down bit it looked really shiny like it was something done recently. im picking up new battery for my cam after work so I will post pics this evening

 

[1946Zephyr]

Re: 73 4 hp seahorse what I found under the flywheel

When I saw the head line of this thread, I was expecting you to say you found a mouse nest under the flywheel.

I serviced a guy's Honda one time that had a buch of rats nesting under the hood and rats pissed all over the powerhead and had it badly corroded.

Darned little rodents can reek havoc on things sometimes.

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

well it was making a squeeking sound

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

here are the pictures of the scraping. By the way I tried to wiggle the crankshaft again and there is movement but its almost imperceptible, I mean like maybe a little more than a hair width movement.

 

[58rude]

Re: 73 4 hp seahorse what I found under the flywheel

Cranks looks pretty rusty. Flywheel was probably not seated on the taper right. Bet it was cocked to one side a little.

 

[wilde1j]

Re: 73 4 hp seahorse what I found under the flywheel

^^^ Agree. Both the flywheel bore and the crank look bad. They need to be carefully lapped (do not remove too much metal or the crank and the flywheel will be junk.) The flywheel should NEVER hit anything when rotating, period.

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

The pictures make it look really bad but it is not. I just checked it out with a high intensity flash light. There is no pitting and the rust is very light surface rust that formed since we had light fog this morning. I was able to wipe it away with a cloth and it looks fine.

 

[58rude]

Re: 73 4 hp seahorse what I found under the flywheel

The flywheel is warped or the taper is not even when its seating, or the wrong flywheel is on it. How long have you had this motor, has it done it since you got it, or did it just start?

 

[danray35e]

Re: 73 4 hp seahorse what I found under the flywheel

had it a couple of weeks guy who had before said it had not been run un two years. I only just got it started this last weekend

 

[58rude]

Re: 73 4 hp seahorse what I found under the flywheel

Check and see if the flywheel is warped. If its not clean it up and lightly lap it as suggested. Then see if it will seat even and don't overtorque it when you put it back on.