Jackshaft problem

I do not have a shift kit but it seems to me the two parts that the shaft sits in is spreading out and probably the time element is how long it takes to get some heat into the left bearing so that bearing is no longer retaining the shaft position.

That is my guess. The fix is to retain the left bearing on the shaft.

1) drill into the shaft for a spacer/ big washer and bolt to retain the shaft onto the bearing.
2) Or some blue locktite on the shaft to bearing fit.

Is the sprokets in line?,,,is the plate that is making the the gap look bent?,,,is the chain on the crank freewheel gear too tight?,,, I see what looks like rub marks on the shaft and spacer edge on the pedal side of the shaft,is the motor moving (is the motor mount tight?),,,IS THE pedal and gears on the right side lined up ,could it be pulling the shaft to the pedal side and bowing the other plate and making a gap on the left side?

I just saw a pic of another jackshaft and the angle brace is not showing on yours,I didn't notice this before
Go down to thread #9 for the pic,,, http://motorbicycling.com/f39/re-assembly-60cc-port-matched-setup-25989.html
Should be a simple fix with a wire welder and a piece of flat iron stock

corgi's got it - it's side plate flex "walking" the shaft out... even if you've mounted the plates parallel, they're not staying that way under load & you'll need to reinforce them

Looks like the other fellows got you straightened out. Probably could have avoided those problems by buying a Sick Bike Parts Shifter Kit.

Pablo,
I knew that was coming....Didn't think it would take this long though.

timboellner said:

Pablo,
I knew that was coming....Didn't think it would take this long though.

Click to expand...

Sorry. Just kinda lose my cool sometimes. Just a few dollars more. Got people calling saying: "Wish I would have known you have the original, feel like I've been ripped off by this Chinese one.....dang thing doesn't work"

Pablo,
I think its hilarious that another vendor who ripped off your shift kit with a China clone, copywrite's their new products... It would be nice if you could come up with an inframe 4 stroke (titan clone would be nice) kit with your shifter kit and your company would run circles around thatsjacked and beat them at their own game.

Please sign me up as customer #1.

Drewd said:

Pablo,
I think its hilarious that another vendor who ripped off your shift kit with a China clone, copywrite's their new products... It would be nice if you could come up with an inframe 4 stroke (titan clone would be nice) kit with your shifter kit and your company would run circles around thatsjacked and beat them at their own game.

Please sign me up as customer #1.

Click to expand...

it does suck when someone snags your idea and makes a cheap copy mine is a sick bike part set up high miles on her now but my gears walked also after miles and miles its bound to happen and i dont ride nice on my mountain bike i tig welded a small washer just as a retainer no more problems ive been snapping chains and deraleurs using a 36t front sprocket and my reed motor shoots up hills in a hurry very low 1 st gear like a trials bike lovin its a monster i love the shift kit pablo on my 7 th build now loving this hobby on top of all my other ones may need another shift kit soon !!!!

i got the sbp kit when it first came out. never once made an entire trip without it flim-flaming out on me. the bike is still sitting under my mobile home. i understand that the mount has now been modified

Pablo's the man when it comes to shift kit/jack shaft tech.
For a second, just looking at the 3 pics, I thought it might be an early S.P.B. shift kit, with out the reinforcement bar on the left plate, but then I realized it was one of the cheap Chinese copies.
I had one rider come into my shop with the same problem.
I first welded a reinforcing bar on the left side plate.

Then cut a small piece of 5/8s I.D. tubing and slid it over the shaft between the cogs, this acted as a spacer.

I then removed the shaft as a unit and re ground the flat for the set screw, then using a slightly longer pointed set screw I reassembled the shaft, tightening the new pointed screw to mark the spot, I then removed the shaft again and drilled a shallow hole in the shaft at that spot, a drop of red loctite was added for insurance.
I then reassembled the shaft from the right hand side with its new spacer tube and more positively mounted drive cog and reinforced left side plate.
This stopped the left side drive cog from "walking" under load.
I then adjusted his primary and secondary drive chains properly and the problem stopped.
S.P.B. rules!~
Next time, by the real one first!
BBB
p.s.
(how about super heavy duty shift kits for Morinis!)