EW350 Flywheel Removal

[Douglas52]

The clutch on my EW350 is getting a bit vague in its action so I'd like to give it an overhaul. It appears that to remove the flywheel from the crankshaft, a threaded puller is required. This  screws into a threaded recess in the flywheel hub. Does anyone have the dimensions or an alternative method of flywheel removal?
Thanks
Steve

[Chris]

Hi Steve
The puller for the EW flywheel is available from the LDMCC Spares Scheme for members of the Club. If you wish to make one then the thread size inside the flywheel is 1.7/16" x 26 tpi. The bolt through the centre to bear on the end of the crankshaft may be any size but I would suggest at least 1/2". Do not try to remove the flywheel by any other means. The wall thickness of the flywheel around the centre hub is only about 1/8" thick. A three leg puller used on the rim will almost certainly distort the flywheel leaving it rotating like a dog's hind leg. Chris.

[Douglas52]

Hi Chris
Thanks for the info. I'll probably make one. I take it the 26TPI thread is right hand and not left hand like many of the modern flywheel pullers?

[Chris]

Hi Steve
 Yes, it is a normal right hand thread on the puller. A warning! It is not at all unusual for this very fine thread in the flywheel to have become damaged due to a not too well fitting socket spanner coming into contact with the thread while tightening the flywheel nut. It might be difficult in this case to engage the puller. It might help to cut a diagonal saw cut in the first few threads of the puller to help clear any slight damage providing you can get the puller to engage in the thread. In a severe case I have successfully removed a stubborn flywheel with a badly damaged thread by tapping out two of the holes into which the springs are located and making two studs to screw into these with threads on their outer ends to take a bridge piece and centre bolt. The problem still remains that having extracted the flywheel one still needs the large tap to rectify the damaged thread so that it can be extracted properly in the future. But if a tap can be located to suit at least it is possible to rectify the thread as the crankshaft is no longer in the way as it is when the flywheel is on its taper.
Chris.

[Chris]

Hi again Steve
I have found a sketch and set of instructions for the alternative method of removing the flywheel described above. I made up this set and used it myself. I also loaned it to another member who had tried just about everything to remove his flywheel and it worked for him. Good Luck. Chris.

[Douglas52]

Hi Chris
Thanks for the pointers. Unfortunately I had already made it using a  spare flywheel to set the thread fit while the puller workpiece was still mounted on the lathe. I had to overcut the threads to get the flywheel on - partly due to my sub-par machining skills and partly due to flywheel the thread damage which you allude to but I hadn't picked up on. Consequently the thread was a fairly loose fit in the flywheel on the bike, but I had heaps of engagement length so wasn't too concerned. It did the job and the flywheel popped off with a minimum of fuss.
Thanks again.
Cheers
Steve

[Douglas52]

Hi Chris
Looks like we were both replying at the same time.
Attached is a photo of the puller made with your guidance.
The centre bolt is m12(sorry) from a jap bike flywheel puller.
Really must get a decent thread cutting tool  - or sharpen the old one!
Cheers
Steve

[Chris]

Hi Steve
No problem, it all adds useful information to The Forum and will no doubt help someone else in the future. I did say that any size bolt would do in the centre. I just used a bolt available. Chris.

[cycarmark]

The 1-7/16" 26 threads on my flywheel were very worn, so I had to go with the puller shown in the sketch.  I did modify it somewhat, instead of threading holes in the flywheel, the two bolts were cut so they would fit inside the hole and could be positioned so they would catch on the underside of the flywheel.  Attached is a picture of the puller, it worked great!