crankshaft question

[marklm]

HI, just bought a 80 440 trailfire. We got it to run with some fresh gas and it would not idle. So after allot reading pulled the engine to check the crank seals. The clutch side seal was half ripped apart I could see right through it. The flywheel side was still in one piece. I had to take the sled to a garage to have the clutch pulled. I bought a comet 102c puller but my air supply would not budge it. Got the clutch off and took sled home to remove engine. Tried my self with proper puller to remove flywheel and again not enough air. I soaked it with oil heated it some but I could not budge it. So I took it to a snowmobile grave yard in Mount Pleasant Mi. the pulled the flywheel off for me. He had the same kind of puller but after he used the air impact on it he gave it a couple blows with a 2 lb hammer and it popped off. I was happy and went home to tear it apart. The engine did run before I did all this. Now after looking at the crank I found too much gap between one rod and the crank weight. I guess I do not know the name of the parts that has a pin through them and the rod hangs on it. But one side checked within tolereces but the other side is way out. I tried setting the crank with the seal keepers on the crank in the top case and it would not drop in because of this. So I got to looking at the crank I see that on one side of the round crank weight the pin that goes through both of the round weights the pin does not come all the way flush like the other 3 are. So I have to much gap and the crank will not go back down into the case. I did not notice this when I took it apart. How can this happen? Ive thought this over and over about using the pullers to remove the clutch and flywheel could that have done this. I dont see how. But anyway I think my crank is shot or can this be fixed. I thought of putting it in a vice and try to squeeze it back together but that may make it worse. Any crank experts out there that can tell me how to fix this. Ive included I hope I can post pictures of it. Thanks for any information on this.

[tmartin]

I wouldn't recommend pinching in a vise. These cranks are all aligned and indexed and toleranced and what not. A good crank shaft shop can repair that. Thats the pto end. An extrmely out of balance clutch may cause the pto end to walk apart. I doubt it was from pulling the clutch or flywheel unless you were using a bfh and really swinging. The rust on the crank isnt good either. You may consider finding a good used crank which may be a cheaper option. Hope this sends you in the right direction.

[JDT]

Cranks are all pressed together. It is possible to seperate them slighly, like in the picture you have posted, from removal of the flywheel and or clutch.

Best advise is to have it checked over and repressed as suggested by tmartin.

[ihengineer76]

If the rust is just on the counterweights, and the bearings all are smooth and tight, you should be fine. Most engines I've rebuilt have a little rust on the counterweights.

[marklm]

thanks for all the response to my crankshaft questions. I took the crank in to a shop the fixed the gap but the mechanic said he would replace the crank because one of the bearings had some bad spots in it. I got one from a salvage yard and he checked it out I put the motor back together last night and put it back in and mixed some fresh 42 to one gas and fired it up after taking some time.
While taking this sled apart I removed the gas tank and cleaned it out got a new screen check valve and new hose and a new pump. Boiled the carb out and put a new main jet in. It did not start right off the bat. I had to bleed the air bubbles out of the gas lines and we pulled and pulled to no avail. Later I checked that I had set the screw that holds up the slide in the carb and I had not so I turned it in 1 1/2 from where I felt the slide move up and then it fired up. Smoked allot. But I oiled up things good before putting it back together and I used 6 oz oil for 2 gal of gas and that figures out to about 42 to one. Im going to run it a bit like that then add some straight gas.
That was what Ive done today with the 1980 jd trailfire. thanks again. Mark

[harleysportster]

Your fuel ratio is slightly off but running a rebuilt engine with 40 to 1 is a good thing. Instead of adding straight gas to that, mix up a batch of 50 to 1 and add it as the tank as it nears being empty. Never add straight gas.