750ss squarecase flywheel puller

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eddiec
Cucciolo - the Lil Pup
Posts: 2
Joined: Sun Jan 03, 2016 4:35 am

750ss squarecase flywheel puller

Post by eddiec » Sun Jan 03, 2016 7:40 am

I have a problem with pulling the flywheel off my 750 SS squarecase ...
http://comber.org/img/D750ss/750ss.jpg

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...
http://comber.org/img/D750ss/750ssFlywheelTop.JPG
http://comber.org/img/D750ss/750ssFlywheelBack.JPG

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...
http://comber.org/img/D750ss/750ssFlywheel.JPG

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...
http://tinyurl.com/go38jgf

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.

wdietz186
851
Posts: 629
Joined: Sun Sep 10, 2006 4:40 pm

Re: 750ss squarecase flywheel puller

Post by wdietz186 » Sun Jan 03, 2016 5:36 pm

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.

wdietz186
851
Posts: 629
Joined: Sun Sep 10, 2006 4:40 pm

Re: 750ss squarecase flywheel puller

Post by wdietz186 » Sun Jan 03, 2016 5:41 pm

P.S. A puller like the harmonic balancer puller in that Amazon ad is what you will need.

ducadini
750 GT
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Re: 750ss squarecase flywheel puller

Post by ducadini » Tue Jan 12, 2016 11:34 pm

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.

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

eddiec
Cucciolo - the Lil Pup
Posts: 2
Joined: Sun Jan 03, 2016 4:35 am

Re: 750ss squarecase flywheel puller

Post by eddiec » Wed Jan 13, 2016 11:34 am

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!

Eddie

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