What engine? Because both my Ducatis (916 & M900) have lightweight flywheels but this matters not as the holding tool fits onto the rotor in the middle so, even without a flywheel I could still hold it.

Otherwise some say the penny between the flywheel and starter gear works? and I've done it on a small 2-stroke children's field bike but I'd be wary on a Ducati, given the required torque and the cost of the parts if they break.

You could always use a clutch tool to hold with the engine in gear but that may not be the best way either as it's a lot of torque through the gearbox/crankshaft?

 

The penny.

I've done it multiple times, sometimes on the same set of gears. and not once had a problem. And I have reused my Nichols nuts 4 times without a problem.

I think that I have done 145-150 ftlbs for the Nichols, and somewhere around 180 ftlbs on standard nuts. My point, with those figures the penny has never wronged me.

The clutch holding tool will sometimes break the clutch basket. With someone on it and holding the brake, you might reach the number, but with the amount of flex from the crank, gears, brake, and rear tire your numbers will be off.

 

The coin, or any bit of soft metal will work. I think it's best to lock the mechanism without using the gearbox or clutch when you can, but I doubt the torque required would damage the gearbox anyway. I don't quite understand why you would want a hardened retaining nut, soft usually works better.

 

@DukeDesmo It's an 853 built around an 748R crank with various other assorted bits but it had an OE Duc flywheel nut on it so that's getting junked.

I have some thin sheet aluminum I can put in there too but I will try the penny first. SSR says 140 on each nut since it's a double jam style setup but it'll be getting some red loctite too.

Hadn't bought the flywheel too since I didn't know if it would work. Will try it this weekend once parts come in. Thanks a bunch!

 

I use this tool from Motion Pro.

 

That's a nice tool, hopefully it works better than the fork oil level tool that broke the first time I used it lol. I'll check that out too.


Edit: Just ordered that MotionPro gear jammer, found it on amazon for about 13 bucks with two day prime shipping. Will check it ouit this weekend as I should have my replacement gear and sprag flange by then.

 

I am replacing my sprag clutch this weekend, it seems I have not planned enough for this operation. My Torque wrench only goes to 140f/#

Have a penny, but no time to order any fancy tools, and had not planned on needing an assistant either. The sprag clutch is really getting bad, takes 10 minutes to start on a cold day as the starter just spins.

 

RockAZ, if you absolutely have to ride the bike if the sprag doesn't catch try rotating the rear wheel forward in gear. I had the sprag fail to catch this fall on the day I was supposed to take the bike out for a run with some friends. It caught, let go. Caught, let go again, then it just spun. Tossed it in first, spun the motor over using the rear wheel about a half rotation and then tried again and it caught.


Just note, the longer you try to start it with a bad sprag the more you're gonna chew up the flange and the bearing race on the big gear. That's what happened to me. Sprag was crap in the motor when I got it but it would always eventually catch. Well my last oil change revealed a pile of very fine steel particles, and when I pulled the big gear the race surface was pitted and ground up as was the contact surfaces on the sprag.



Not cool lol. I bought a good second hand gear and flange on the cheap to replace them. Just note you should check everything over especially if it's been failing for a while.

 

Yep, rotating the wheel in gear has helped a few times. Never does this after warmed up/started once per day. Only the first start after overnight when it is cold out. Didn't have the problem all summer even once although it started spinning last January. The job really can't be put off any longer as you said it is probably chewing up stuff, and I have all the parts ready to go but thought I had the tools needed until I saw this thread.

 

Even if your torque wrench only goes to 140ft/lb, with high strength red threadlock rotating the nut another 25-30 degrees should apply sufficient torque to get you in the ballpark of where it needs to be.

I'm curious if anyone has ever tried running a second large thin lock washer that you can stake over to lock the nut like on the time layshaft gear uses. Wouldn't add significant weight and would provide a direct mechanical force on the nut to prevent it backing off.