Rotor fit to taper slipping

[Guest]

I have read a few threads on this, I torqued up my stator bolt and after a few hundred kilometers, the starter started slipping and I found the bolt holding the stator had loosened and the rotor was slipping on the tapered shaft. You will also see some scaring in the pictures.
I have seen the following sugestions:
1) Use red locktite on the tapered shaft and on the bolt.
2) Someone used a aluminium shim made from a coke tin plus red loctite
3) Someone used a feelergauge as a shim
4) Some have said to use nothing on the taper, just red loctite the bolt.
5) I have heard of putting some valve lapping compound on the tapered shaft.
6) I have been warned that green loctite will need heating to remove the rotor.

On the pictures the scarring can be seen and please let me know what you think. I would also prefer to be able to get it off again one day.












Thank you in anticipation.

[focus frenzy]

been there done that!!
what you need is Permatex sleeve retainer for the rotor and standard red loctite for the bolt.

http://www.permatex.com/products/motorcycle/motorcycle_thread_compounds/motorcycle_retaining_compounds/motorcycle_Permatex_High_Temperature_Sleeve_Retainer.htm

you will also need some of this to make sure it works right.

http://www.permatex.com/products/motorcycle/motorcycle_thread_compounds/motorcycle_thread_compounds_activators/motorcycle_Permatex_Surface_Prep_Activator_for_Anaerobics.htm

the damage to my crank and rotor was worse than that, and it has been a year since I "glued" it back on using the sleeve retainer and it is still going strong.

[chef1366]

The crank taper doesn't look too bad.
I know you're an experienced wrencher so I hope I don't insult. How much tourque are you putting on it?
Could the open end of the starter clutch be beyond spec? If so I have read threads where a pop can was used to thicken the taper. Plus this way it will come off some day.

[posplayr]

I have limited knowledge

only done this 3 times but douched the tapered end and the bolt both with red locktite and tightened with an impact wrench. No loosening problems so far. I think this is what Rapid Ray does as well.
Seems to work

Pos

P.S. green locktite on the rear hex bolts

[Matchless]

been there done that!!
what you need is Permatex sleeve retainer for the rotor and standard red loctite for the bolt.

http://www.permatex.com/products/motorcycle/motorcycle_thread_compounds/motorcycle_retaining_compounds/motorcycle_Permatex_High_Temperature_Sleeve_Retainer.htm

you will also need some of this to make sure it works right.

http://www.permatex.com/products/motorcycle/motorcycle_thread_compounds/motorcycle_thread_compounds_activators/motorcycle_Permatex_Surface_Prep_Activator_for_Anaerobics.htm

the damage to my crank and rotor was worse than that, and it has been a year since I "glued" it back on using the sleeve retainer and it is still going strong.

Focus,
Thanks, it is quite difficult to get someone who stocks a range of loctite or permatex products here and if you get something a compete new engine will be cheaper! They also only stock large quantities, 50 ml and up.

I just got hold of the equivalent for the red loctite 271 and it is called a RiChem stud grade T60. They also have a super stud grade and then two green ones made for shafts. I think the green one will be the equivalent of the green loctite or very close. What are your thoughts on using the green loctite and in my case the equivalent? Will it be possible to get the rotor off again!

I also recall that I never did a proper degreasing of the bolt and threads as well, so here may be one of many reasons.
Thanks for the reply and keep well.

[Matchless]

The crank taper doesn't look too bad.
I know you're an experienced wrencher so I hope I don't insult. How much tourque are you putting on it?
Could the open end of the starter clutch be beyond spec? If so I have read threads where a pop can was used to thicken the taper. Plus this way it will come off some day.

chef1366,
This is just my hobby and I am definitely not an experienced wrencher and you have asked a very valid question. I recall that I did not find it overly difficult to torque the bolt up to what I believed then to be the correct torque. I assume that I was using 90 -100 N/m. Then I looked at a thread on making massive rotor holders and it did not gel.
The likelyhood of the taper being worn is quite possible and that made me wonder about a shim as well, but I cannot see if it is or not. Focus frenzy has used that very strong permatex stuff and if I use the green loctite I may never get the rotor off again!
Thanks for the reply.

[Matchless]

only done this 3 times but douched the tapered end and the bolt both with red locktite and tightened with an impact wrench. No loosening problems so far. I think this is what Rapid Ray does as well.
Seems to work

Pos

P.S. green locktite on the rear hex bolts

posplayr,
Thanks for that reply. Can you recall the condition of the tapered part and the inside of the rotor, was it better than mine? Chef1366 says he has seen worse and I do not want to overkill here in case it needs to come off again sometime!
Just for info, mine never gave any indication of slipping when starting but slipped immediately on first spin after a long trip. I think heat may have had something to do with this as well.

[rustybronco]

Matchless,
on the rear of the taper on the crankshaft there is a ridge. is that ridge grease/crud or metal?

went the starter laid down it's tools before as you said, was the reason the same as this time, the bolt loosening up?

if the cause of the no crank then, is the same as it is now. I would go with the suggestion given by Focus and use green "stud and bearing mount" on the taper and red on the bolt and worry about getting it off when and if you have to.

if the green is hard to obtain, or is a budget breaker (knowing the prices down there it probably is) use the red on both.

I would use green for piece of mind...

P.S. sometimes we take for granted the availability of things around here.

[Matchless]

Matchless,
on the rear of the taper on the crankshaft there is a ridge. is that ridge grease/crud or metal?

went the starter laid down it's tools before as you said, was the reason the same as this time, the bolt loosening up?

if the cause of the no crank then, is the same as it is now. I would go with the suggestion given by Focus and use green "stud and bearing mount" on the taper and red on the bolt and worry about getting it off when and if you have to.

if the green is hard to obtain, or is a budget breaker (knowing the prices down there it probably is) use the red on both.

I would use green for piece of mind...

P.S. sometimes we take for granted the availability of things around here.

OK cleaned it up and used red threadlocker on the bolt and tapered flange, torqued up and the large starter gear was binding and not spinning freely. Fortunately my air impact driver was at hand an even then the bolt was hard to get out. Within minutes the red stuff had cured. I used the impact driver to drive my bolt used as a puller and again, quite a job the red had dried hard and the rotor was properly gued to the shaft. Then again torqued up without threadlocker and the one rotor obviously is worn more than the other and it binds against the gear. It will work with a shim on the taper if needed I think.
Swopped rotor, red stuff and torqued to 100Nm and all seems well.
Am I glad I did not use the green stuff!!! The red is hard enough and we also get a super red for studs!
The mistake I made was not to pull the small idler gear off immediately after torqueing and ensuring the large one spins freely in one direction and the curing took place faster than I expected.
If this fails I will go green!

Thanks for your inputs it gave me some insight into what I was suposed to do and why. now time will tell

PS Instead of making a huge clamp to hold the rotor for torqueing, just put a copper coin in the teeth of the idler and large gear, it will lock in place and you will easily get the 100Nm on the medium length torgue wrench.
Hope this helps someone else as well.