yet another head scratcher

seattle##gs

Joined
Oct 28, 2014
Messages
1,866
Country flag
Gear box 1972

With motor turned off it shifts easily. Start the bike up and it requires more effort to shift. more effort than normal. Also, it is reluctant to shift into first with out some grinding. This seems to be a reoccurring theme lately when I put a gearbox back together. Primary and rear chains are adjusted properly. I replaced the mainshaft in this one because of a bend. I put in a good used one. The shifting into first improved slightly. All other bushings and bearings have been replaced except for the camplate spindle bush and the gearchange quadrant bush because those two require removing the gearbox. They appeared to have no excessive movement so I left them alone.
The shifter shaft has been shimmed but still has .020 movement. What am I missing?
Once under way all shifting is good and positive but requires more foot pressure than normal. When hot it shifts a little easier into first but it has to be carefully done.
 
always a possibility but all plates are new and the basket and center are in good condition.
One more clue...when it's idling and on the center stand the rear wheel is really turning. I am using a common #90 gear oil...perhaps going to a thinner GB oil would help.
 
I've had similar difficult into first from neutral in past. Happened when at a stop preparing to pull away. Not a problem if rear wheel is rolling when trying to select first.
Seemed to go away after some primary and final drive chain adjusting. Put it down to too much primary chain loading putting some aside loading on the shaft.
 
Clutch drag or sleeve gear bushes to tight. You should be able to push the kick start lever down with very little hand pressure with the clutch lever pulled in if not the clutch is dragging.
 
All of the above.
Your clutch is engaging when it should be neutral.
90 wt. is heavy for clutch lube. Not the sole cause but a contributor.
 
seattle##gs said:
always a possibility but all plates are new and the basket and center are in good condition.
One more clue...when it's idling and on the center stand the rear wheel is really turning. I am using a common #90 gear oil...perhaps going to a thinner GB oil would help.
Click to expand...
Does the rear wheel turn when your clutch lever is pulled in?
 
Lineslinger said:
All of the above.
Your clutch is engaging when it should be neutral.
90 wt. is heavy for clutch lube. Not the sole cause but a contributor.
Click to expand...
OP mentions #90 for GB oil, not for primary chaincase. EP90 is the Workshop manual spec for GB...but of course who knows what #90 modern lube is. I run modern Redline ShockProof Heavy just fine in there.
 
These Non unitary suckers pull the primary tight , Via final drive chain .
Once youve set the primary tension , you need to set the adjusters TIGHT Against the Thru Bolt ,
or itll pull back & ' take up the slack .If you use any throttle .

Putting it on the mainstand / beer crate - and fiddling & fettling , help . Chain tensions ' tune ' shifting etc .

Incidently , the " FETTLE " debated at some stage , is primarilly a railway term . Yoive gotta have the rails JUST SO
if you want the 100 mph express to Stay on the Rails . Fine Tuning ! a eye for detail , and the mind on the job .
Unsuitable for currant youth !

A person who maintains railway lines. · Someone whose job is to sand and grind small imperfections from metal and ceramic castings.
Click to expand...
 
Be sure to set drive chain tension with rear wheel on ground, taking at least bike weight or even with a rider seated, else the spec tension will not be sufficient as swingarm rotates upward from shock compression under load. With SA drooping down from bike on CS, you need to add more slack to chain deflect measurement.
 
Tornado said:
Be sure to set drive chain tension with rear wheel on ground, taking at least bike weight or even with a rider seated, else the spec tension will not be sufficient as swingarm rotates upward from shock compression under load. With SA drooping down from bike on CS, you need to add more slack to chain deflect measurement.
Click to expand...
Must have rider seated, or proxy. Or a couple sacks of feed.
 
I will double check the chain tension but I'm sure it is OK. I pulled in the clutch lever and the kick start lever goes down with no resistance. A curious thing, though. I start it at 9 o'clock and it stops at 6:30 and won't go any further when I try to start it. With the clutch lever held in it goes easily past that. No idea why. It does not stop with a clank, metal on metal, just won't go further.
Just remembered..the sleeve gear bushes were very snug on the shaft. Can I expect them to wear in in a couple of hundred miles or do I need to pull it apart again and give a bit of clearance?
 
seattle##gs said:
A curious thing, though. I start it at 9 o'clock and it stops at 6:30 and won't go any further when I try to start it.
Click to expand...

If the ratchet engages at 9 o'clock then the lever should normally travel to about the 5:30 - 5:00 o'clock position before it reaches the 'stop' so possibly something is not right with the kickstart ratchet pawl mechanism or stop plates.
 
"Just remembered..the sleeve gear bushes were very snug on the shaft. Can I expect them to wear in in a couple of hundred miles or do I need to pull it apart again and give a bit of clearance?"

Nope. It'll take a LOOOOOOONG time to wear in.

When you notice the anomaly, the time to address it is right then.
 
L.A.B. said:
If the ratchet engages at 9 o'clock then the lever should normally travel to about the 5:30 - 5:00 o'clock position before it reaches the 'stop' so possibly something is not right with the kickstart ratchet pawl mechanism or stop plates.
Click to expand...
The stopper plate is mounted in the transmission inner cover. No ability to change.
If the kick lever is mounted too far forward, that would explain it.
Otherwise, The observation of the lever not going to it's expected limit is anecdotal. I would offer that with engine resistance, the (human) kicker simply runs out of available body mechanics to push it further. (Versus clutch in, no resistance)
 
Last edited:
You must log in or register to reply here.
Back
Top