Friggin' flywheel

[skucera]

I'm replacing my starter clutch.  (Yeah, I should have done that over the winter, but....)  My pulley pullers were too small to reach around the surprising depth of the flywheel, so I bought one big enough to reach, but the claws are so big that there isn't room for the third claw... just not enough clearance between the flywheel and the case... only 10mm or so wide, and maybe 5mm front to back.

How do you folks get this thing off?  What sort of puller do you use?

I suppose I could grind down one of the claws, but I've heard that this thing is pressed on hard and takes tremendous force to pull if off, and I'd hate to break one thinned down claw in the process.

Thanks,
Scott

[fret not]

The flywheel fits a taper on the end of the crank shaft, and has a key for alignment.  I used a sort of triangular puller with 3 bolts going through the puller and threading into the flywheel.  There is a big 'bolt' in the center of the puller that presses against the end of the crank shaft.  It takes considerable force on the center 'bolt' and a big hammer to shock the flywheel free. 

I got my puller at Harbor Fright for about $20.

[b_racuda]

This kind of puller.

[Jirik]

This is mine home-made:

[Rikugun]

Jirik, well done on the puller.

[Slav91]

I have used regular claw puller. Not much of a hasle it fell off less then a minute. :D

[davecut]

I also made my own puller i cut a 2 inch length off a piece of standard scaffold tube its approx 2 inch diameter
i then cut 3 pieces of conduit again 2 inches long its approx 22mm and welded them to the scaffold tube at
12 oclock 4oclock and 8 oclock i then found a large bolt i think it was 16mm about 3inches long and welded the
nut to a 2 inch washer needs to be thick and then welded the washer to the scaffold tube so as the nut is now
on the inside of the tube. Do you get me so far?
Then you need 3x m10 bolts with a finer thread than standard i think 1.25 about 3 inches long and 3 washers
slightly bigger than the 22mm conduit.
Your now almost there the only thing now is the large centre bolt will just push on the flywheel, so you need to
reduce the end of the bolt so it pushes on the crankshaft. So if you have the luxury of a lathe, you need an
end on the bolt 10mm in diameter and about a 10mm protrusion.
This sounds quite complicated but it is made from basically scrap and the only cost was the 3x m10 bolts
and some mig wire and about an hour of my time. Works well and cost very little. Dave.

[skucera]

Thanks, everyone, for the pictures of the bolt-through puller.  I've actually owned one of these for more than 20 years, but I forgot all about it because I usually use my claw pullers.  I bought some long M8 bolts and stout 5/16 washers today on the way home from work.  I test fitted a bolt in the flywheel.  I'll rig it up tomorrow.  After my daughter's school awards thing tonight, I'm just too wiped out to get into it tonight.   :P

Scott

[fret not]

Scott, you need a BIG bolt in the center so it will withstand a few sincere strokes from a big hammer.  Don't worry about the crankshaft, it will withstand the 'abuse'.
When you go to replace the flywheel make sure you clean both mating surfaces.  You don't want any oil or other debris on the mating surfaces.

[skucera]

Immense forces by Scott Kucera, on Flickr

My big bolt was a little too long, and distorted under compression.  My boy and I teamed up on it last night and didn't budge the flywheel.  He steadied the wrench, and I wanged with the 9# hammer.  Today I picked up a shorter bolt, but I won't have time to work on it again until after dinner.  Wish us luck.

Scott

[cvincer]

Those 3 bolts that attach the puller to the flywheel have to be screwed in & torqued up equally .... if not, the flywheel will

never come off the tapered shaft & its woodruff key  &  in such a situation the harder you tighten up the big centre bolt, the more

firmly the flywheel is locked in place on the tapered shaft/woodruff key.   Also, from the photo it does not look like the centre bolt

is pulling in a straight line.

[skucera]

Sorry for not updating everyone promptly.  I got the flywheel/rotor off in spectacular fashion on Saturday.  Bang!  I couldn't work on it Sunday because my oldest daughter graduated from high school. :D  This evening after work I swapped in the new starter clutch, reassembled it all, filled the engine with oil, and pushed the starter button.  The starter motor turns, but the engine isn't being turned over by it.

I double-checked the wiring to the starter motor, and its wiring is exactly as the wiring diagram depicts it, so it can't be turning backward.  I spun the starter gear inside the starter clutch after I assembled it, and it turned freely one way and gripped the other, just the way I thought it would, but after putting it all back together no joy.

???

So, tomorrow night I will take it all apart again and see where the starter motor isn't connecting to the crankshaft.  Grrr.....

Scott



P.S.--
Has anyone every heard of that starter gear behind and inside the starter clutch wearing down to a circumference too small for the starter clutch to grip when there's oil in the engine?  I know, I'm desperate for any way forward....

[fret not]

There is a specified minimum diameter of the part of the gear where the rollers ride.  I remember seeing it listed when looking in a shop manual, but I don't recall what that number is.  However, unless that surface on your gear visibly disturbed I doubt it has worn down that much.  I have seen ripples worn into such surfaces, caused when it all goes bad and is continued to be used.  You can access the Yamaha shop manual via POD's signature line link.

If the gear spins one direction but not the other the starter clutch would appear to be working.  Is the starter engaging with that gear?

[davecut]

Hi scott i am new to these bikes but my first job was exactly what you are doing at the moment, what i found on the
rear of the flywheel where the rollers sit, as they spin they make grooves in the face of the flywheel and can
restrict  the rollers from contacting the gear wheel. What i did was fitted a flap wheel to my 115mm grinder
and smoothed out these grooves. I also checked that all the plungers that retain the springs were moving
freely and slightly stretched the springs to give a little more push on the rollers. I also rebuilt my starter motor,
you can try out your work with the casing off oil drained, take out the plugs so the engine wont fire, and you will
need to hold the pin on the middle gear shaft, i held a wooden hammer shaft handle against this to stop it coming
out, you might feel better to get a friend to press the start button, you can then concentrate on what is going on.
Best of luck mine works fine now so i can move on with my next problem huge flames shooting out the top of
the carbs, not working on it at the mo as i am selling my daily runner a nt650v deauville and trying to finish my
xj750 ready for the road. Dave

[fret not]

Well, I have looked through 3 different manuals for the minimum diameter of the starter gear and find it listed NOWHERE!  Now I'm troubled about where I DID see it, and why there is no apparent mention in neither the factory shop manual, Haines, nor Clymer manuals.  The only minimum diameter limit I found so far today is for the commutator of the starter motor.  DANG!  It ain't the stuff ya don't know that is so dangerous, it's the stuff you DO know but just ain't so. :-[

[QBS]

davecut, excellent plan, with apparently the desired results.  Thank you for sharing.

[davecut]

Thanks QBS its always good to get some positive feed back if scott follows my procedure i am sure he will get
the right result, NOW can anyone tell me why i have 6 inch flames shooting out the top of my carbs i will be a
happy bunny, my thoughts are spark at the wrong time or valve timing incorrect. ANY THOUGHTS, Dave.

[Rikugun]

davecut's "first fire up" thread here:

http://ridersofvision.net/rovforum/index.php?topic=15638.msg143888#msg143888

[skucera]

I've been busy, and I've learned a lot more about my motorcycle.  First, I drained the oil I had just put in and pulled the starter.  Through the hole in the case I confirmed that the starter clutch was working fine, with the starter gear spun freely one way, and absolutely locked up the other just as it should, so the starter clutch I just installed is still just fine.

Next I took the starter down and had it tested on NAPA's automated starter test fixture, and it tested out perfectly, and spun very strongly... strongly enough to startle the guy running the rig.

Next, I tested my new (as of last summer) starter relay, and it works perfectly when energized with jumper wires from my wife's car battery.

So, I tested the "new" battery (after some reflection I realized was three years old) on my battery load tester and it was on the borderline between weak and bad.  Aha!  I bought a new Exide battery only to get home and realize that it had no battery caps in the packaging... none.  Of course, it was just after the store closed, so I couldn't return it.  I've got to wait until tomorrow to exchange it for one with caps in the box.

After that, I figured I'd just better remount the starter motor and get the crankcase filled with oil, and we'll test the theory once I get the new battery filled with electrolyte and charged tomorrow after work.

Scott

[QBS]

Regarding your battery cap situation:  Does your new battery have holes that caps go into?