Hard bang shifting into first

[Mrjohnahawley]

While I am waiting on the rest of my fuel system rebuild parts I am turning my attention to other issues I plan to work on. When the bike was completely together there was a bang/jerk when shifting into 1st. Any thoughts? At the time the PO had the idle set at 1500 rpms. The carbs had NEVER been tended to, verified by the original owner. All kinds of fuel and vac issues. Is there a chance any of this contributed to the bang? The bike is non running right now since the carbs are out. I'm just searching for theories. Thanks

[cajun31]

higher idle

The higher idle setting is what causes that bang. Mine does the same thing when I have the idle set that high. Ideal is at about 1100. These bikes are clunky when shifting in to first so keeping the idle lower helps.

[motoman]

Clutch adjustment

can be a big help, even tho these trannys are a bit clunky and shift like a Russian tractor. Adjust slack into the cable at lever perch, remove round two screw held cover, phillips screwdriver holding screw on clutch pivot throw-out assembly and loosen the lock nut. Back screw out a bit so there's no resistance, come back in a bit till resistance and LIGHTLY seated is felt, then back out screw a 1/4 turn and lock in place with lock nut. Back to cable assembly and re-adjust cable slack.

[Mrjohnahawley]

The higher idle setting is what causes that bang. Mine does the same thing when I have the idle set that high. Ideal is at about 1100. These bikes are clunky when shifting in to first so keeping the idle lower helps.

That's a relief! I was hoping not to have a tranny problem. Thanks for the input

[Mrjohnahawley]

can be a big help, even tho these trannys are a bit clunky and shift like a Russian tractor. Adjust slack into the cable at lever perch, remove round two screw held cover, phillips screwdriver holding screw on clutch pivot throw-out assembly and loosen the lock nut. Back screw out a bit so there's no resistance, come back in a bit till resistance and LIGHTLY seated is felt, then back out screw a 1/4 turn and lock in place with lock nut. Back to cable assembly and re-adjust cable slack.

Thanks, I will give that a try when I get it running again.

[SFerinTEXAS]

Some of us (me at least) avoid shifting into first as much as possible on this bike when stationary because 1st gear is not synchronized. Lots of past talk about that. And how to avoid it. Doing it at a high RPM makes me cringe. Search 1st (or 2nd)gear repair. No fun but doable.

[motoman]

Some of us (me at least) avoid shifting into first as much as possible on this bike when stationary because 1st gear is not synchronized. Lots of past talk about that. And how to avoid it. Doing it at a high RPM makes me cringe. Search 1st (or 2nd)gear repair. No fun but doable.

No synchronizers in these trannies......or any bike tranny for that matter.

[madmax-im]

The best way to shift into first gear if its for the first time is to just hit the shifter quickly and firmly....DO NOT try to be gentle and slowly try to engage the first gear...you'll get alot of grinding...common knowledge...experience...once underway and then coming to a stop I downshift into 1st @ 5mph...no clunk but then you have to hold the clutch in while stopped...which IMHO you should do in the event the car behind you isnt paying attention and you need to move outta there....DAMHIK

[CatatonicBug]

...which IMHO you should do in the event the car behind you isnt paying attention and you need to move outta there....DAMHIK

Definitely! NEVER sit in traffic in neutral!! Yes, the lever is stiff, and if the light is a long one, your hand can start to cramp, but you can just slide to the end of the lever to add more leverage if needed. Get in a habit of downshifting to 1st while still moving, and the clunk will all but disappear.

[mack]

Snatch

It's called snatch. It's normal but is worse at higher idle rpm. Your bikes idle speck is 950-1050 rpm. The primary shaft has two component jobs. On the side opposite the clutch is a set of conical springs attched to the shaft that compress under rotation. Right beside that is a set of rounded notches and the other side fits into these notches with quite a bit of play. This whole set up is designed to take up the bang from shifting into first as well of some of the torque when power shifting.
It's all normal but reduced idle rpm can help it not sound so bad.

[Mrjohnahawley]

All good info. I forgot to mention that after I reinstalled my carbs after the rebuild and before the fuel leak I did back the idle down to 950 or so. Just was so fixated on it running properly I didn't even try the shifter. More parts arriving tomorrow so hopefully this weekend I will have my answer. Thanks for the tips!