Boss replacement

[Tiptonite]

I have just purchased a smooth boss to replace the stock one on my 2007 kymco agility 50.  It's a simple job but I do not have an impact wrench to get the nut off of the front pulley (crankshaft).  Is there any other way to loosen up the nut without an impact wrench?

[Pimpy1]

Use at your own risk. Those fins are brittle. https://www.google.com/search?hl=en&safe=off&client=firefox-a&hs=KuW&rls=org.mozilla:en-US:official&q=wrench+to+hold+variator+nut&bav=on.2,or.r_gc.r_pw.r_qf.&bpcl=35466521&biw=1472&bih=700&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=N4KIUOLVJa600QGJxoDwDA

[blue]

I do this all the time I find a open end wrench the well fit on the teeth of the fly wheel and wedge it in side the drive box were the x s go across and with a ratchet just give the nut a pull for dear live. So far I have not broken anything.

[Pimpy1]

I watched a riding buddy bust his case like that 2 weeks ago. I used to wedge a small wrench against the teeth myself to remove the nut. I ordered a small tool for mine that works well now.

[blue]

the right tools do help. I need need to get me a air impact because I have been working on a lot of scoots latly.
even a cordless would be good...........

[streido]

If its never been off since it left Kymco then chances are u wont get the nut off without an impact wrench. You can try oyher methods shown on youtube but i would buy the impact wrench myself. Mine was like £20-£23 delivered so theyre not expensive, why chance bjstin your case or damaging the outer variator teeth?

[skippy]

+ 1 for impact wrench. mine cost £26 from mechine mart. looks cheep but its been up to the job every time. why spend £!0 on a variator locking tool that does one job.... use an impact that you will uses all the time.

[mono]

Some experts advise against the use of an impact wrench on a split crankshaft (like ours very probably is). Since the crankpin only has an interference fit in the cheeks of the crankshaft, the impact might mess up the alignment of the crankshaft halves..... And any misalignment will eat your crankshaft bearings sooner or later...

Lots of people use impact wrenches on their crankshafts, and even professional mechanics tend to do this, and most will deny the possibility of damage - but then again, lots of people watch their crankshaft bearings fail for no apparent reason...  

I'm not taking the risk.. A variator holding tool does the job perfectly, it will only cost a small amount of money once, and it will probably fit and outlast any Kymco 4T or 139QMB engine that's yet to be made....

And, fixing it to the crankcase with two bolts takes exactly as much time as connecting the impact wrench to the compressor and finding the right socket...  

[Tiptonite]

Thanks for all the advice.  I ended up wedging a small wrench against the teeth and everything worked out fine.  It is a completely different scooter now and well worth the buy.

[Pimpy1]

Glad it worked out.

[streido]

Cool.