Dasa crankshaft

[ISeeWetPeople]

So i got this dasa 900 and i am rebuilding it. But i found this "pipe" between shaft and seals. This is second time that i came across with this kind of setup. But last time that crankshaft was broken and i bought a new one. But this shaft is ok and i wonder can i use this
This "pipe" spins freely on crankshaft and in my opinion it is airleak between crank and that pipe. So why there is this pipe and what can i do to still run with this crankshaft dont want to buy new if possible.

 

[Big Kahuna]

@Jr.

 

[mikidymac]

Looks like a Redi-Sleeve for repairing a seal surface. Probably so you just replace that instead of the crank journal when the seals wear a groove in it. It would typically be a tight fit and use a locker like Loctite 640 Sleeve Retainer.

 

[Jr.]

Its typical that collar comes loose with wear. If your not rebuilding crankshaft at this point, use sleeve retaining compound like suggested above. That will act as a retaining seal. Then when the Coupler is torqued on, it will loc the collar in place and prevent it from spinning on the crank. Note, in my experience, if that collar is loose like that.
then inspect the crank completely. Its closer to rebuild time than you think?

P

 

[Wetbuffalo]

I had this exact same thing happen on my 964. Rear seal collar loosened up started sucking air there and lost the rear cylinder. Interesting to see that crank works is using the oem style seal and not the big fat one that adr and wsm uses.

 

[Freakrider]

My PHP 10mm crank for TPE1105 had same collar spinning loose and it cut a perfect line into coupler o-ring seal. I found this on a 100 plus hr rebuild inspection and also found one big end thrust washer very thin and ready to break very soon on the one closest to coupler. The other thrust washers were fine but I've been told by PHP perhaps it was related to constant shock impacts or couplers hitting.

 

[ISeeWetPeople]

Ok so i thought right. It is a sleeve. At this point i will just use loctite to make sure there will be no air leak.
Or new crankshaft if needed. Yesterday i opened the engine and did not inspect that crank any further.
But im still wondering. If that sleeve is tightened with coupler how is it possible it to open

 

[Moto360]

I would suggest replacing with a brand new collar from Yamaha. A new one will have a tight fit.

 

[Wetbuffalo]

What should the New Sleeve clearance be? What is the measuring procedure? Maximum allowable groove depth? How is the Sleeve Inner Diameter selected?

I can say this, I had mine reused and did the green loctite but it still came lose again. They are an oem part. I think they are cheap enough that anytime you are doing a crank rebuild it should be replaced. You can see how discolored mine is from spinning on the crank.

 

[ISeeWetPeople]

I think if i use bearings glue.. Same stuff that i glue crankshaft bearings to case when new bearings dont have that pin hole.. That should do it.. It is pretty good stuff

And thanks to everyone