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H2 shift drum detent
http://www.kawi2strokes.com/forum/viewtopic.php?f=2&t=13533		 Page 1 of 4
Author:  DGA [ Thu Aug 30, 2018 8:25 am ]
Post subject:  H2 shift drum detent
Could someone please measure the width of the shift drum detent slot/ groove for me? Looking at something and don't have the clutch sidecover off my bike, if someone had a drum laying around and could measure that. Looks to be about .125" but need to know.
Author:  DGA [ Sun Sep 02, 2018 5:26 pm ]
Post subject:  Re: H2 shift drum detent
Nobody has one sitting handy they could measure with a dial caliper?
Author:  Ja-Moo [ Sun Sep 02, 2018 6:06 pm ]
Post subject:  Re: H2 shift drum detent
Are you talking the distance between the pins in the shift drum?
Author:  H2RTuner [ Sun Sep 02, 2018 6:39 pm ]
Post subject:  Re: H2 shift drum detent
I think he is speaking of the actual groove the pins pass through, that the detent, shift lever and holder plate actuate/hold the drum in. I'd go look, but I don't have a drum out of an engine here.
Author:  Ja-Moo [ Sun Sep 02, 2018 9:33 pm ]
Post subject:  Re: H2 shift drum detent
Image
Author:  DGA [ Tue Sep 04, 2018 7:25 am ]
Post subject:  Re: H2 shift drum detent
Ok, perfect, thank you!
Author:  DGA [ Tue Sep 04, 2018 2:58 pm ]
Post subject:  Re: H2 shift drum detent
So, my idea is to make a roller shift drum detent arm. My H2, I complained early on that it has almost zero shift detent feel at the pedal. Much of this is because of the long skinny shift shaft running through to the other side of the gearbox, but still. I have had a few first gear jump outs, to a neutral between first and second, and it makes me cringe. It never does it with a normal, shift from a standstill, or downshift while riding, but sometimes will if I select neutral, then the light goes green and I'm still rolling, and click it back in. Maybe I didn't pull the clutch fully at the same time. More than likely that it has used shift forks etc, there were no spares that I know of in New Zealand in the early '90s, so I think my brother used what he had. Nevertheless, the point that it only does this with an odd shift tells me that the shift drum might not be positioned fully, and the small dog rounding shoves it out of gear.
I can find 3mm wide ball bearings in various diameters, so can make an arm to hold one of these on the tip. Add some more spring tension, and check the detent force with a dial torque gauge to make sure I have improved it. Not a ton of work, but might be a worthwhile improvement.
Author:  Ja-Moo [ Tue Sep 04, 2018 3:39 pm ]
Post subject:  Re: H2 shift drum detent
It's just easier to learn to hold the shift lever full up until you have let the clutch lever all the way out. And as usual, get rid of all play in the shifter system.
Author:  H2RTuner [ Tue Sep 04, 2018 5:57 pm ]
Post subject:  Re: H2 shift drum detent
Once you get the clutch off, so you can see all the shift linkages, there are a few things to look for. Everything I outline should become very evident and clear when you take a closer look.

First is to take a close look at the stop pin in the center of the shift lever. The piin, at rest, should have the same distance from each part of the cutout that surrounds it. The edge of the cutout is the stop for each shifting operation, upper for down shift, lower for up shift.

When the stop is in place, fully against the pin, the claw at the drum pins should be the same distance. This ensures the claw both returns to the centered position when the shift lever is at its centered position, and the claw is set up to move the next pin, either direction, for the next shift.

If the centering in the cutout isn't letting the claw come back enough to move into the next shift operation, you can't shift the transmission one way, can the other. There are various reasons for the claw not engaging the next pin, not returning to a centered position. Most common are two issues, bent shift stop pin, and/or the return hairpin spring isn't setting the shifter back at dead center on the pin. Some springs sit offset a small amount.

To rectify the stop pin issues, and get the lever throws equal up and down, Kawasaki devised a revised shift stop pin, offset, so it can be adjusted, and outlined on an F Series service bulletin. The pin id fairly universal, firs A, G, F, S and H series engines. Once you see one in action, you will get it straight off.

Also, the H1R and H2R racer shift detents are set up different than street bikes, they use some F series detents, and have a cut away on the boss the pins run through, and give a neutral between first and second. Look at the F Series detents for more info on them.

Also, even with an adjustable stop pin in place, it might be necessary to relieve the stop area on the shift lever that the pin stops, IF more shift lever travel is needed AFTER centering the opening up on the pin. As I said, this will be very evident once you just take a good, slow, careful look at how it works, and how that one is working.

I just spoke with John Ulrich the other day, and he still wonders how I found this shifting problem in his Honda CB500 Four decades ago. It was a magazine test bike, and he bought it dirt cheap because it wouldn't shift back down after going into high gear without literally hammering the shift lever. He had NO money to spend, was just getting started as a reporter, and really needed the help, as more than a few people had been "helping" him fix it, to the tune of new transmission, shift drum, forks, shift linkage. So, while he took the clutch off the engine, I rode a then new TL250 trials bike he was evaluating for a magazine, around his front yard in suburban La Mirada, Ca. He called me over after he got the clutch off, and I said "there it is, John, bent shifter stop pin". We got into my car and drove to LeBard & Underwood, a Honda dealer in La Habra, Ca., and bought a new pin, total cost was $1.58, with tax included. Seems the bike had been taken oout of service when the last evaluator had dropped it on its left side, not riding it, just sitting. Bent the shifter stop pin up just enough to not allow the shift claw to get into the right position to move the shift drum the other way.

It doesn't take much to ruin a whole day. Do look for that service bulletin, probably on Dale's Resources site, for the F Series offset eccentric shifter stop pin. All this info isn't just for an H series Kawasaki, it is for any pin stopped shift lever in any bike.

Also, on the dirt bikes, take a look at the actual shifter claw used on the F series, there are two more outcroppings that interact into the drum pins, to not allow over shifting, both directions. H series race bikes used these to stop over and under shifting as a positive stop for th drum rotation, but, they require a guide to be used, and a part of the oil ledge above the starter shaft to be relieved to clear them. Good to employ, not easy to fit, but, well worth it. I had this setup on my hot rod street H2R, and never missed a shift, ever.
Author:  DGA [ Tue Sep 04, 2018 6:05 pm ]
Post subject:  Re: H2 shift drum detent
I do try to make a conscious effort to fully shift, but as I said, it only happens when its a rushed shift, like I'm about to get rear ended by traffic with a green light, etc. I pretty much only ride in the city, don't have the luxury of nice winding open roads etc, and its a lot of start, stop crap. Sucks, but it's what I have to deal with.
Still, I don't see any reason to not try to improve it to be at least close to modern shift mechanisms. The other end of the spectrum is my '83 KZ1100 Spectre, it has a truck like gearbox, you have to use foot hurting effort to shift that thing, almost. Perfect is my Yamaha XV750, light, solid feeling, positive detent feel on the foot, really nice. Both of those bikes have the shift mech. on the LH side though.
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