1988 430 AE Auto mainshaft sticking

When I purchased this bike new from the shop they performed the mods to the springs etc to prevent them breaking. I rode it a couple of times but it would not have more than 1 - 2 hours on it. I never really liked it that much and at the time had an '88 430 WR that I rode the wheels off before moving onto a TE610. This bike ended up in the shed as-is for years. I went to resurrect it this summer and get it going again to see whether I would keep it or move it on.
Anyway, when I started it, everything was fine, but then when I stopped it, it kind of made a clunking sound as it stopped. Never heard that sound before. Sounded like a broken spring. I pulled off the crankcase cover and noticed 2 of the springs seemed very loose. I thought maybe they had lost their tension sitting there all these years so I figured that I would swap them out for some spares that I had when I bought the bike. That's when the fun started.
I just could not get the primary clutch off the shaft. I trashed the original Husky puller and 2 other flywheel pullers befoe re I managed to get it off with a custom made puller. But it sure put up a serious fight.
Now that it is off, I can see it seems to have fused itself onto the crankshaft. I could understand this happening if the main clutch spring hub had of come loose on the shaft and spun-welded itself on (this happened to a taper shaft sprocket on an old 73 400CR I used to have). But this is not the case here as the woodruff key is in tact. It seems that it has spot welded itself in position.
What causes this? Anybody seen this before?

Wow, Mine was awfully hard to get off as well.
I tried a few times and stopped before I did any damage.
So I put the puller on and had it all torqued up and applied some heat and it popped off.
I also had a small spot were it looked like a small piece of the hub was stuck to the crank.
I cleaned it up real good with a file before I put it back togehter.

Husky Jim, thanks for the reply. It sounds like a auto specific issue since I have never come across it before on my old 430. My theory and I am completely guessing here, is that it must be the auto clutch hub that flys around a lot and is not perfectly balanced therefore it must pickup slight movement on the shaft which vibrates & fuses itself together. This hub really took a hell of a lot of force and a reasonable amount of heat to get it off - and this was an as-new low hour bike. I will follow your example and clean up the shaft with emery and then lap the two surfaces together with paste and see how it goes. The only way I can see to prevent this going forward would be to regularly remove and constantly lap the surfaces together to prevent them from fusing.
BTW - I have been tracking your thread recently and it has given me inspiration to get this bike going again and do something with it. I have a few thoughts of what to do with it but I don't think I will put it back together stock, I think I will pull the engine and put it into something else. I'll keep you posted.

I have seen that phenomenon before. It is kind of a strange thing as the keyway isn't sheared. Like the ignition taper you are supposed to re torque that a fews times in the first hour or two. Kind of a pain with the water cooling. I had one go bad on my watch and I always deal with the water issue and take the cover off to re torque. The one I had go bad was on a 430, I got as parts bikes or engines a 420 which had been repaired by some aircraft shop but the repair failed and it now shows whatever lathe cutting they did before re surfacing. I bought a parts 500 engine which was fused more than what you picture. If you study the parts sheets you will notice the 430 has only needle bearing as in your picture in post 1 here. The 500 had a longer crank stub and two needle bearings, That clutch hub has a spiral cut into it, the earlier bronze shoes have the slots on a bit of a twist to get the same effect which might be a possible cause. I have my doubts that the auto design scaled up very well, the little bearing in the outer cover is perhaps an indication. Do what you want I would avoid the 500 and try and de bore to the same or a bit less than the stroke if I was to ride it a lot. I have a 51cc husqvarna chain saw I bought in 1993 which is just about worn out but not the clutch which is just two parts not three and dry.

I am kind of intrested in the theory of how that happens.

fran

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