It seems like an eternity ago that I came to a skidding halt whilst still running-in my new piston, rings & head. bought those as I'd partially melted a piston during testing for jet sizing, & dry seized it because not enough oil. The bike was still running, but a bit of melted ali coated the plug thread, & while I was checking the plug in various throttle positions, all of a sudden the thread starts getting ugly on me, & before I realised what was going on I had a chewed up plug thread.
Bugger it! It was a series of stoopid errors that lead to me needing some new parts to run-in. I'd been spooked by a noisy belt, & thought it must've been because of running a non-OEM belt....well it wasn't ! Finally twigged it was the final drive gearbox....like Duh, splash....I just fell in, I think. Or, Kerchink!...the penny just dropped. Below are the happy snaps of my drive belt & some oil that pooed out as it got so boiled-up in there.
So I've bought a Malossi UpGear set that increases the gearing by about 10%. I chose the Upgear because I didn't want to go with OEM spec with helical gears. I hope by decreasing the roller weights I can still have good acceleration. Time will tell.
Here is the UpGear kit. The Malossi part # is 67 3677.
1st problem. The loose gear supplied has an ID of 17mm, but the OEM shaft is 19mm. Took it to a local machine shop & got them to turn down the shaft to make a tight fit. Biffed off the the old gear with a sledge hammer. Pressed on the new gear onto the newly machined shaft using a mechanical press.
All the materials are hardened & the machining blunted some lathe tool cutting tips. I supplied some ultra hard tips from my toolmaking days, but the rural backyard machinist didn't have a holder suitable, & wasn't used to working with such materials.
Ferk, it was a drama.
Anyways, here is the finished item.
The dude put some Loctite gear on it, & I'm letting it get fully cured before re-assembly.
Ok, I know it's a crappy pic below. The deepest & smallest bearing in the final drive gearbox has an ID of 10mm & is seated in a blind hole. How the hell do ya get that out??? Ask your local motorcycle shop which is 50K's away.....nope can't help.
Continued below pic.
That remover was made up from an 8mm anchor bolt which has a hook on the end. The clips are to stop the shaft of the anchor bolt from expanding. Slid the anchor bolt in the 10mm bearing hole, screwed it up, hooked a large shifter on the end, & then placed a jumbo shifter to slide on the "hooked shifter" thus acting as a slide hammer. A few whacks & it was out.....gave myself a pat on the back & said, "McGyver does it again!" ...(if you don't know the mid 80's TV series "McGyver": it's basically a stooge who "gets the bad guy" & gets into situations whereby making atomic bombs out of Cornflake boxes & hairclips sort of antics always saves the day somehow.
You can see the expanded tube of the achor bolt just poking out. All the greasy crap on there is grease because I tried "The Hydraulic Method"....doesn't work because no seal in the bearing so the grease just poos out when ya whack it.
Bearings needed for the Bug Bandit final drive gearbox overhaul are:-
1 x 6203
1 x 6202
2 x 6200 You've got to pop out the seals & wash out the grease before assembly. I'll be using some Loctite Bearing Lock. Will do a number of oil flushes for running-in. I'm not really sure how things will work out with this because of the lathe work.....it needs to be perfectly concentric because of the high RPMs in there. Any slight deviation might make shitloads of vibration & soon self-destruct. The gear that was pushed on seems to be concentric, however, there seems to be some axial (not radial) deviation there...so I really don't know how it'll work out.
Will keep you posted.
Rob
Sunday 14.10.07
I got the gearbox back together, today. I had a bit of trouble with the Loctite Bearing Lock as it seemed as though it was setting before I had a chance to get the bearing fully home in its seat. I had to hammer in a few bearing to make sure they were fully home.
On top of that I forgot to include some thrust washers! :( I had them right next to the job, but was so focused on get the assembly back together. Might not matter so much as I'm guessing they were "in action" when coasting, that, because of the helical cut on the gear, the intermediate gear would have been pushed against its own housing....now with the straight cut that wont happen.
The finished job doesn't feel that good when trying to roatate it, & I hope I've not flat pitted some races from the hammering. Anyways, the whole lot is dry (oil-free) & with new straight cut gears which might account for the clunky feel. Just have to make sure it gets plenty of running-in & flushing before declaring it "All AOK".
Testing on Monday.