Need help,countershaft sprocket

[mokster13]

Hi,I'm a newby so bare with me.My countershaft is stripped,not the gearing but just the threads that hold the countershift sprocket nut in place.Near as I can tell the previous owner crossthreaded it in with an impact and it finally backed off and took the threads with it.I'm trying to find a fix without dropping the motor and splitting the cases.I thank all in advance for any advice.

[rotortech]

mokster,

This is a tough one to fix. Some with this problem used a new nut and found that it would hold spec torque even though it looked like there weren't enough threads. You might try that unless the shaft is just completely smooth now. I have heard talk of drilling and tapping the center of the shaft but do not know of anyone who did it. I would at least try that. All drilling and tapping will be by hand and requires patience. I have done a lot of hand tapping so it seems reasonable to me.

Several have just tack welded the sprocket to the shaft so they could ride. This is very undesirable but it seems to be common practice among people selling broken bikes.

I hope there are some smarter folks than me who can suggest something better.

[yamaha_george]

Hi,
Only you will know if a new nut will work on the damaged shaft.
You could drill and tap a hole in the shaft BUT the shaft is likely of a steel that is quite hard & the FZR is not work in place friendly as it has no side stand you would need a paddock stand back & front for any kind of stability when drilling and any chance of getting the hole straight down the shaft. so as to make anew secure locking device.

Some where in the WIKI there is a piece by one of our members of changing out the gears on an FZR whilst the bike is on its side. I DO NOT know for sure if the countershaft can be withdrawn when the bike is like this.

If it can be removed from the bike , take it and a NEW nut to an engineers to have the threaded area built up with weld (plough shear rod is good for this work)then turned down and finally anew set of threads cut.

[rotortech]

You must split the case to get that shaft out. I don't think it can be done in the frame since the head and cylinders must come off to split the case.

[apsolus]

a few little beads of weld did it for me. i used a hose clamp as asurance it would stay put. then when i changed the sproket i just chiseled the weld away and did it all over again. after doing that though i was always checking it making sure it wasnt backing off. not a smart fix but whatever

[rotortech]

a few little beads of weld did it for me. i used a hose clamp as asurance it would stay put. then when i changed the sproket i just chiseled the weld away and did it all over again. after doing that though i was always checking it making sure it wasnt backing off. not a smart fix but whatever

It is a desperate fix until you can split the case or get another whole engine.

[apsolus]

right, after spending 800 bucks on a complete bike i sure wasnt gonna go out and buy and new engine. hey dont bash my hose clamp technique, on a side note heres a story, i was new to chain bikes, the fzr was my first i was on a trip from houston tx to columbus ga around 900 miles. well before the trip i checked the bike over really good, what my bike had for the sproket was a huge metal clamp with a pinch bolt in it, i couldve sworn it was a stock part cause it looked so "right" well im in alabama and the bike just falls apart out of no where, damn clamp was gone and the sproket was just laying there! then i noticed the shaft had what looked like threads on it, well hell the PO never told me about this! that bastard. i walked a few miles to the next exit and bought some hose clamps, i made it the rest of the way to GA like that, took it to the yamaha dealer in the area and he told me the gory details, oh your gonna need a new output shaft, one million hours of labor, yada yada. muffler shop here i come! just a story im not trying to taint anyones better judgement guys

[reelrazor]

Thread file.

http://www.sjdiscounttools.com/kdt2228.html

Or, file smooth all the way around it and drop down one size(even if that means S.A.E. , and get the appropriate nut. (use a BRAND NEW OEM locktab washer)

[mokster13]

Thank you,great ideas.I got a 9/16 die and I hope to be able to re-tap it,maybe even put a spot weld on it or drill it for a cotter pin to make sure it doesn't back out.Thanks all for the help and ideas.

[reelrazor]

,maybe even put a spot weld on it or drill it for a cotter pin to make sure it doesn't back out.

BRAND NEW OEM locktab washer....that is what the locktab does for you. Get an NEW OEM one-accept no substitutes. Torque the nut, and engage the locktab properly and it WILL NOT back out.

[mokster13]

Yes you are absolutely right,unfortunately I'm paying for a previous owners mistake.I just wanna get her running soon.Right now I have 2 projects and haven't been able to ride for some time.

[mokster13]

By the way your sig line is great,and right on the money

[rotortech]

By the way your sig line is great,and right on the money

Whose?

Use the little quote button when you want to refer to a specific post.

[mokster13]

By the way your sig line is great,and right on the money

Whose?

Use the little quote button when you want to refer to a specific post.

Thanks rotortech,I was actually refering to reelrazor's borrowed quote from Douglas Adams,never heard it before and thought it rang true.I thank everyone for the advice they gave me.