Page 1 of 1

750ss squarecase flywheel puller

Posted: Sun Jan 03, 2016 7:40 am
by eddiec
I have a problem with pulling the flywheel off my 750 SS squarecase ...

The correct puller is very difficult to find because the clearance behind the flywheel is only 2-3 mm and the foot of a standard puller is too thick to fit behind the flywheel.

You can see this on the top and back images...

This was a notorious problem on the pre-Bosch ignition 750s and I wonder if Ducati have addressed this problem by tapping the primary gear, see the six threads in the photo...

Unfortunately the photo is not directly-on. The diameter of the gear is 79 mm. I wonder what the diameter of the tapped thread is. M8 would be a typical puller thread and this sort of puller may work if so...

So my questions are;

Are these tapped threads intended for pulling the gear?
Anybody know what thread size they are?
If it pulls the gear, will the flywheel come with it or is that another issue?

Thanks in anticipation,
Eddie, London UK.

Re: 750ss squarecase flywheel puller

Posted: Sun Jan 03, 2016 5:36 pm
by wdietz186
Eddie, Your SS has an aftermarket ignition installed. Normally the the primary gear has a flywheel bolted to it with 3 holes in its face to facilitate removal. Your flywheel has been removed and replaced with a trigger for the electronic ignition. Your best bet for removal would be to use the holes in the gear to hold bolts for a gear puller. The holes in the gear are 8x1.25. Be sure to protect the end of the crank from possible damage caused by the pressure bolt on the puller you use. I think a steering wheel puller might be sturdy enough to use on the gear. Larger press type gear pullers might not allow for bolt holes as close together as are on the gear. When trying to remove, put a fair amount of pulling pressure on the gear with the puller and using a big brass or aluminum punch,smack it sharply with a heavy hammer to jar the gear off of the taper on the crank. If it hasn't been tightened by a Gorilla it should pop off pretty easily. If it is stubborn heating the gear can help.

Re: 750ss squarecase flywheel puller

Posted: Sun Jan 03, 2016 5:41 pm
by wdietz186
P.S. A puller like the harmonic balancer puller in that Amazon ad is what you will need.

Re: 750ss squarecase flywheel puller

Posted: Tue Jan 12, 2016 11:34 pm
by ducadini
I don't think the Yamaha type puller will work.
I noticed two bolts in the primary to hold the special flywheel, so You have four threaded holes left but that doesn't work with the threebolt puller.
You could go for a two bolt puller (fabricating it yourself) but from memory those primary/flywheels combos were HARD to remove, and I don't think two M8 bolts would be strong enough. Better you go for the four bolts but i'm afraid there's no readily available.
Sadly the only alternative is the Darmah type puller, the basket with the ring that slides over the primary gear.


Re: 750ss squarecase flywheel puller

Posted: Wed Jan 13, 2016 11:34 am
by eddiec
Thanks both.

The position at the moment is that I have the M8 pullers - both 2 and 3 legged but the bike is at a friend’s house about an hour away so it's not easy to keep going over and back to try things out.

I may mange it at the weekend and then I suspect that I'll be looking for your valuable advice again!