cracked flywheel Evinrude 4 hp

rebuilding a 1975 Evinrude 4 hp just noticed a crack in the flywheel - should I replace the flywheel or try to run the motor with a cracked flywheel - the crack runs from the outside to the center

Your going to want to find a new one, if that thing grenades at 5000 rpm it is going to do a lot of damage. Think shrapnel...

Plus if it is cracked it is unbalanced which is hard on the bearings etc on that motor.

thanks - I was thinking the same thing - I found a couple on ebay - i'll get one of those ordered unless some one knows a better place 2 get one

Is it a crack or a casting imperfection? I have seen casting 'lines' on flywheels that look like cracks, but they're not. If the flywheel was removed incorrectly it could indeed be a crack. If it was 'pulled wrong' with enough force to crack it, then the flywheel is likely also bent. If it's bent it will wobble and you can see it by turning the motor over. A crack can usually be seen on both sides, likely it would go through the material.

Replace a cracked flywheel. A casting mark is no reason to go to the expense.

there was a big chip where the crack started -got this motor free so I can spend a little money on it

Maybe it got pulled wrong. Who Knows. Three jaw pullers are not the right tool. They almost always ruin the flywheel. The way to do it right is with a 3 bolt puller. The three bolts thread into the flywheel. I use an impact gun(carefully, just burp it) to tighten the pressing screw. Pops 'em right off.

I don't know if you live nearby. There's a couple of those 4hp engines out in my storage building. What is your model number?

boat2fast,
thanks for the offer but I talked to a local repair person and he didn't have any that would fit mine so I ordered a new one.

when I get it done i'll post some pictures

got the new flywheel - put it on and works great - now I have to deal with a fuel pump problem. won't keep running on high unless I keep pumping the bulb - I'm guessing a new fuel pump is required.

You can get those same symptoms by having an air leak in the fuel system. The leak can be anywhere between the fuel inside the tank to where the fuel line connects to the fuel pump. If you have any fuel line connections that are even slightly suspicious as a possible leak point, I'd fix those first and try it again.

JMichael
Thanks for the suggestion - i'll do that before I order a new fuel pump.

pull the output of the full pump and spin the fly wheel. if fuel shoots all over the place (you could put something on the end of the line to capture the fuel but what fun is that) then the pump is more than likely good.