Suzuki dt65 parts or project?

[3ric]

I have a 1987 Suzuki dt65 that I purchased as a parts motor. I bought it from a guy who said the head was seized. Turned out to be just a rusted drive shaft bearing in the lower unit. So the power head turns smooth, no scoring on cylinders. I was hoping that the motor was restorable ....but....dun dun duh dun....then I noticed that the shaft coming out the top of the flywheel appears bent. I am pretty sure the nut is not cross threaded, the shaft is bent. See the photo. Are my dreams of restoring this motor over? By some slim chance of fate, could that shaft not be part of the crank?

 

[Faztbullet]

Could be warped flywheel also...take flywheel off and inspect. That shaft is the crank.

 

[3ric]

Ok, guess I’ll be fabricating one of those devices to hold flywheel in place to remove the nut. I should note, that when I turn the flywheel it spins perfectly flat and the engine spins smooth, like it should, yet that arbor seems to be leaning 7-10 degrees off center

 

[3ric]

Ok, so I figured out why the nut was cockeyed, the shaft was twisted off at the nut. Someone must have been pretty strong. But the shaft appears to be straight below the break. I was thinking about drilling a point for a puller to push off of in the center of the break and go ahead and pull the flywheel. Thoughts?

I threaded the nut on as far as it would go in the other pic and it is only about half the threads get covered. What is the opinion that I could weld and thread the missing portion back on?

 

[Faztbullet]

To do it properly the crank needs to come out of motor but if your going to go that far just replace it. Other option is to get another crank nut and split it in half and torque to spec

 

[3ric]

To do it properly the crank needs to come out of motor but if your going to go that far just replace it. Other option is to get another crank nut and split it in half and torque to spec

Hmmm, I’m not willing to replace the crank, just too much work for my talents. What do you mean by split the nut? As in if the nut is 1/2 inch thick and the threads are 1/4” tall then cut the nut 1/4” tall? Do you think it would still handle the 140 lbs of torque?

I was thinking grinding a taper to the bottom of the broken off piece so I can get weld all the way to the center of the shaft. Then cutting an extra nut in half perpendicular to the axis and remove a quarter inch of each half ring so I could just clamp the two pieces of nut on either side of the break which would hold the broken off piece in place to make sure the thread timing was correct. Tac in place. Then remove the nut and build the weld outward with 7018 rod. Grind then run a die over the threads. The idea being that it would help that nut handle the high amount of torque. Am I delusional?

 

[racerone]

You will likely not be able to torque to 140 FT-LBS with a cobbled up repair.------That might shear the flywheel key.-----Replace the crankshaft I say.

 

[3ric]

You will likely not be able to torque to 140 FT-LBS with a cobbled up repair.------That might shear the flywheel key.-----Replace the crankshaft I say.

As much as I don’t want to hear it, replacing the crank must be the inevitable path...thanks everyone for the input!