Fresh crankshaft

[ecurbruce]

I picked up my freshly rebuilt crankshaft from Syd's Cycles last friday, and am anxious to reassemble my engine!
Any advice on what's important to remember at this point?

Bruce.

[MotoMike]

No help, just a comment.

Lucky dog, driving distance from Syd's

Mike

[joe46ho]

The biggest thing I think you should check/verify is the fitment of the inner race to the crankshaft on each side of the case. if you have already installed new bearings in the case halves, lay each side on your bench (i usually uses 2 small 2x4's to support the case, and still give clearance to slide the crank in. try inserting the crank into each bearing, one at a time. it needs to be a snug fit, but you shouldnt need to force it together gravity should be enough, maybe a light push, thats all. if its tighter than that you will want to slighty hone/polish the inner races of the bearings to make it right. I use a fine grit 3 stone brake hone. it takes a long time to remove any metal, so dont worry about taking too much off. it would be very hard to do so. This tip came from Malcom a while back... it really saves headaches when shimming the crank, and also I prefer to shim the crank to near zero clearance. AND I DO NOT follow what the book says and install a big shim first, and work my way down, this may be a good method if you DO NOT have a dial indicator, and flexbase, or stand to mount it too... but if you DO have one, then measure it with no shim first... this saves a lot of time, and headaches.

P.S. if you dont have shims (for the crank, or bevels) and you can determine what thickness you need first, i will send you some, i have probably 20 of every thickness available. and they could be sent in a regular envelope.

ONE IMPORTANT NOTE I FORGOT...
if you do use a brake hone to hone the inner races, clean them out with solvent/air when you are done, then recoat with oil. AND DO NOT let the inner race spin, i have a little plastic tool i use to hold the race while honing it...

OH... one more thing, very important... make sure you install the gasket (i use a thin film of hylomar to stick it to the case) and tighten all the bolts before making any measurements...

Joe

[joe46ho]

Just though of a couple more key points...
MAKE SURE YOU

Go over your entire gearbox thoroughly, disassemble it, clean all the parts, knock off any highspots, or sharp edges on the engagement dogs. I replace the retaining rings, to each his own though

I would check the mainshaft, and layshaft for straightness on v-blocks (some would say this is overkill, but the manual calls for it)

do not omit the slinger/shim behind the output shaft bearing (chain side)

replace your clutch peg/pushrod seal, and stake it in place (or use the uprgraded seal from nigel)

check your shift rails for straightness, polish them up good, carefully examine the shift forks

then install the gearbox/drum/rails all into the case, and with the case laying on its side, run it through the gears and visually check everything (this is tedious, and not very scientific because only half of the case is supporting it, but i do it anyway)

make sure you dont omit any shims/thrustwashers and if your gear selector drum fits loosely (side to side) with the engine assembled you can get thicker shims for this, i didnt have to do it to mine, but ive heard this does happen due to different case gasket thicknesses, case wear, etc...same goes for the rest of the gearbox...

This may all sound like a lot, but if you do everything right, odds are you will NEVER need to split the cases again... these engine are VERY robust, and reliable if properly built/rebuilt/repaired/cared for...

Joe

[ecurbruce]

Joe,
Wow! thanks for all the valuable information. Especially the gear box tips.
I've had this engine together once, which is how I found the rod big end problem, so yes I have enough shims, thanks for the offer.
But this gear box info, I had no idea just what needed attention in there. It's certainly not too much effort to sort out the tranny as per your reccomendations while it's apart. I have to figure out the retaining rings that you reccomend to be replaced?

Thanks, Bruce.

[joe46ho]

Well, you don't "have" to replace them, but if you can get all of them off and back on without distorting any of them consider yourself very lucky.
If its a wide-case, it has 1 18mm retaining ring, and 4 20mm retaining rings. The part #'s are 0600.16.180 for the 18mm, and 0400.16.290 for the 20mm rings...
Also, don't be at all surprised if your engagement dogs are chipped on your second gear. Actually I would be shocked if they where not, as long as its not to bad, it should be fine... I think this is a weak point, you will notice that all the other gears have more surface area on the dogs, but not second, its very fragile. I don't think there is any way to upgrade/fix this without swapping the whole gear-set out.
Eldert or Nigel would know more about that, if your interested in trying to upgrade it in that area...

Joe