Rotor/Starter clutch question

[woodsrider250]

So my GS all of a sudden would just turn the starter motor, but the crankshaft was not turning. I tore it down yesterday after ordering a puller (and foolishly not a gasket). In taking it apart the starter clutch pucks/springs are all in excellent order, and I was confused as to where the malfunction was occurring. Turns out I didn't even need the puller to get the rotor off. I just used a cordless impact screwdriver to work the nut back and forth across the loctite that was on the crank. This wimpy driver gun was enough to break the nut loose and I didn't even notice that it was coming apart so easily at first. So the culprit HAD to be the fact that the nut wasn't on tight enough. I see in the service manual it's supposed to be 100ft/lbs. So, the questions:

-The taper-fit is the only thing that holds the rotor to the crank, correct? I've seen these keyed (or not) on other engines.
-The taper fit has some scoring from the slippage. I think I should lap the rotor onto the crank end. Has anyone ever done this? I'm concerned I'll end up with too much clearance IE the big driven gear could possibly hit the case if the lapping action 'draws' it in more.

THANKS! Have a gasket on order, and she'll be rocking again soon. In the meantime I rocked a new to me KZ1000P all weekend. Nice bike. The 1100 16v is a superior engine power/delivery wise, but the tractor cams in the P are kinda nice.

 

[Kaiser Sosei]

Yep, there's no key to hold the rotor on. The common advice is to use red lock tite on the taper and to tighten up the nut "real tight". How much is "real tight"? I used an impact to tighten up the nut. If you overtighten, I found the crank would not turn. So less than that. It took me about two tries to get it tight but not too tight.




edit to add link of my adventure.


http://www.thegsresources.com/_forum/showthread.php?184841-Starter-Clutch-and-Crank-Question-80-GS1100&p=1535799&highlight=#post1535799

 

[RedBaron]

As Kaiser has done so have I. I'd knocked off the flywheel 3 or 4 times (Sometimes I like to downshift too aggressively). I ended up using Suzuki thread locker (green) on the taper (which I think is listed as a clean/dry fit in the manual) as that just happened to be what I had around that day. Haven't had a problem since.

 

[blowerbike]

let me guess.....this is on your 82 1100E....nothing but band aids or big bucks to fix it right..
80-82's do this more often than not..

 

[woodsrider250]

^^Indeed. I was hoping I could fix it right by using lapping compound. I'm going to take another look at available clearance. I used to lap rotors on kart engines often as we'd ditch the key to alter timing, but there was a bunch of room. This looks like if you're not careful, one the lapping is perfect, you might need to chuck the big gear/female end up on a lathe to trim off the backside a touch...all IF there is enough clearance to not have the gear hit the case.

Thanks for the help all, I'll try chemicals at worst.

 

[blowerbike]

red lock tight is your friend...
the problem is...when things are wore to much the entire assembly will bind and spin the guts out of your starter...quite ugly when it happens..

 

[woodsrider250]

Thanks. What should I check for wear? Everything inside looks PERFECT aside from the light scoring on the crank taper.

 

[blowerbike]

rotor taper and crank taper.
if the parts are still usable you be able to red lock tite the taper and assemble with an impact and let it hammer for a few seconds.
then try to spin the large SC gear and see if it still turns one way freely(with idler/pin- gear removed).
if it does let it sit overnight and then go for a ride(if it spins the engine and doesn't slip)..
also add some red to the crank threads..

 

[woodsrider250]

Red loctite, and impact gun did the trick. Thanks.

 

[JTGS850GL]

rotor taper and crank taper.
if the parts are still usable you be able to red lock tite the taper and assemble with an impact and let it hammer for a few seconds.
then try to spin the large SC gear and see if it still turns one way freely(with idler/pin- gear removed).
if it does let it sit overnight and then go for a ride(if it spins the engine and doesn't slip)..
also add some red to the crank threads..

Just curious... Is it still possible to disassemble the rotor assembly once you've red Loctited both the taper and the center bolt? I have a rotor on an 80 GS1000 that needs to be mounted and was thinking about doing this as a preventive. Just a little nervous about doing it on a bike with no previous slippage issues.

 

[woodsrider250]

Don't see why a puller wouldn't be able to pull it back off. Use JB weld, maybe not

 

[Joe H]

I have red locktighted a lot of stuff, works great and holds. A bit of heat to get it off, never a problem.
But I still am curious about red locktight on the taper, I have always been told that DRY has the greatest holding power on tapered pressure fit stuff.

 

[blowerbike]

dunt know but for 30 years red lock tite has been my and many engine builder's go to on crank saddle's/crank taper/trans bearing saddle's ect.. to hold in place and fill in voids.
and to Eric..yes the rotor will always be removable..83 and up big 16v. engines may be tough to remove but it is doable.

 

[Joe H]

Do you ever lap the taper to the rotor to help the fit?
Just a lite smear of red lock tight on the taper or something heavier?
Im only asking all these questions so I do it right?..my rotor is currently off and will be going back on in the next couple days.
I also had another thought that may be just crazy, if you gently heated the taper on the rotor and put it on the crank taper and then torqued it down it wouldn't it then cool and be tighter, the only problem I think would be then the nut may also be loose then and need retightening??
Or am I over thinking, which Im really good at