CC Sprocket falls OFF !

Well I just had one hell of a dilemma last night....

As most of you know, in jetting mode so off on a drive to see how the old girl is responding... @ 4000-6500rpm, accelerate and let off the gas, listen for popping, flat spots, acceleration lags etc... All good in this regard...

Off the freeway back home area I start hearing but also feeling (left foot) a slight knocking sound! :ohmy: Immediately pull the clutch in and roll to to the curb side. Listen, no issues, twist the throttle, again, no issues or knocks... Was thinking possibly ignition ping/knock, too lean condition... Nope, all good.

Tried putting into gear and it just didn't feel right but went into gear just the same... Uh oh.... :ohmy:

So down the road I go where now I'm ~ 1/2 mile from home. Down shift ~ 30 mph for turn off the main road into my neighborhood... This is when ALL HELL BREAKS LOOSE!!!

I feel a pretty good knock on my left foot, and a loud grinding noise... Holly CRAPOLA!!!! :ohmy: SP immediately pull in the clutch mid turn and roll to the curb and stop... WTF, she's idling, sounds good, twist the throttle KERKER comes to life as expected...

Let out the clutch slight grinding noise... OH CRAP!
Tried shifting into neutral and any other gear, grinding noise, NADA... OH CRAP!

So, wasn't leaving me beloved there, push her home... So now I'm totally bumming thinking the worst... Split the cases for outer bearing, tranny gears, output shaft etc.... DAMN IT!!! I have a pretty good grinding noise occuring during my push but she's moving so good to go for at least I can get her home to evaluate the situation.

So now I'm pissed & needing some sympathy... :laugh: SO on the phone to my buds for all the possibles... Steve & Plum....

Steve replies and reports no worries, he has a spare tranny, shift drum and shift forks if needed... APE has bearings... Cool, thanks brother!

Then PLUM replies...
These old trannies are somewhat bullet proof! Nopt so sure quite yet it's the tranny due to the symptoms I mentioned.

Check first that the cc sprocket nut didn't back out & the sprocket fell off the splines... I reply WTF, are you serious... Plum replies yup, had seen it many times especially considering you have higher compression pistons, performance cams, ~ 30 more HP & torque numbers and in the fact I have that big fat ass tire on the rear. Check to see if the CC sprocket lock washer lost the tab (sprocket hole).

Well once again my mentor hits it right on the nose 100%...

As can be reviewed, the washer tab broke, the sprocket backed off the spline during my acceleration/deceleration run and the chain cut through the inside of the soft aluminum cover... :ohmy: WHOA!!!! No freaking way but true...

Minimal damage occurred.. Damn, these old 630 O-ring chains are tough... Just a mild scarring! The output drive spline and sprocket teeth are fine... Clean her up, remove all the metal shavings, remove the washer tab off the KZ1000 I just got, torque the sprocket nut (w/Blue loctite this time) adjust the chain tension and go for a ride.... Thank the KZ Gods....

Thanks Steve, Thanks Plum!

I'm glad you and the bike are good to go. All that remain is the ghost sounds that remain every time yoou get up to speed. :blink: Roy

:laugh: :laugh: :laugh:

Wonder if I can patent this..."Custom made Singing Engine Covers" :blink: :huh: :dry: :laugh:

i have 2 or 3 more cable/sprocket covers ...yours if you want it....:blink:

Rock needs another cover to polish.

Thanks for the offer but not required.... I had to file some of the inside cover off in the beginning due to offset cc sprocket as it was...

I'll just file it down smooth and be good to go...

And thanks Roy (Buff)... :laugh: :laugh:

Our sprocket covers must be twins. This same thing happened to me and it damn near trashed the cover. Well on the inside it looks hideous but the outside looks great. Wait untill the generator rotor comes loose and starts smacking the stator, you will think the worst because it is a very destructive sound with the vibration to go with it. Ask me how I can describe that one.

Oh great, so now you tell me this "This same thing happened to me".... Thanks for posting this tid bit of news :laugh: :laugh: :laugh:

You know, in all the years of riding, especially dirt I have never had the cc sprocket nut back off and fall off... But once Plum went through the torque concepts it clicked and made sense... Just never thought of it until now of course.... :blush: :laugh:

Luckily, I was going slow, close to home and was smart enough to pull in that clutch and stop... then of course push the heavy old beast home....

That sound will stay with me for awhile... OMR cuddles on the floor in a corner in the fetal position with the 1000 foot stare in his eyes... :blush:

It was just plain hideous.... Of course you immediately think the worst due to the sound that came from it and start thinking oh holy hell no... I have to remove the engine and split them damn cases again..... Oh NO, cracked another engine case... Great! :laugh: :laugh:

Ah well, KZ Gods were with me on this one.... Got lucky in the end...

lots of forces working on that nut on your sprocket(can i say that on the internet? :S :blink: :huh: :woohoo: )big ol fat back tire is a lot of weight when you openand close that throttle being transmitted back through the chain to that itty bitty countershaft sprocket. now if youll excuse me im off to paint some happy little countershaft sprockets :laugh:

Another reason to stay stock. This same thing has happened to me about 6 times over the years and with stock sprockets/chain my damage was limited to being stranded in terminal neutral and walking home. Glad it worked out no worse for you anyway. The countershaft sprocket nut is one of those unexplainable things. Tighten it to 70 ft/lb invariably it is at 500 ft/lb come time to remove, however it will fall off regularly while riding. A real pain in the azz.

Service manual depicts 108 ft/lbs... :ohmy:

Well after learning this the hard way, will keep an eye on this and confirm it as part of my routine maintenance.

Just got back from my test run.... No problems... :woohoo:

Once again, Thanks Plum!

my city of omaha plumbing code book calls for 200lb plumber hanging on a 1/2" breaker bar and a 5'long piece of 1 1/2" conduit to snug it up just right! :laugh: its simple physics! since i no longer have the physics,im forced to use my simple mind to solve problems! :woohoo: