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KR250 growly symptoms, maybe the clutch ?

Posted: Sun Mar 05, 2017 9:20 pm
by pepsi
Please read my KR250 symptoms.


Here are the good ones

bike shifts great , on the move

runs great, pulls the wheel in 2nd with 220lbs of me

starts pretty good, hot or cold,

runs up to temp left of middle and stays there

no leaks

The rear wheel, chain, front sprocket all turn nicely with no roughness or weirdness

here are the bad ones


As soon as I ride for a few minutes the clutch starts to drag causing it to be impossible to find neutral

I take off in first gear everything is fine then go through a couple of gears and I get a growl like sound seems like it is coming from the clutch side.


(BTW still shifts great on the move)

the "growl" turns itself off at 20mph, like its a speed related problem, pulling in the clutch reving the motor , does not affect it, only slowing to 20mph. weird

I think I'll rebuild the clutch because of the drag.

what could cause the growl?

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Sun Mar 05, 2017 11:40 pm
by pepsi
Another question I have, the warning light comes on after 50 or 60mph (JDM quirk), how does that work?

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 2:50 am
by Gerrit
I think it's a requirement in Japan that if a vehicle exceeds 80 kph (50 mph) a warning light starts blinking. Singapore has a similar requirement- I've regularly experienced an audible warning signal in Singapore taxis whenever the driver went too fast (which was often!).
It's probably activated by a switch of some sort in the speedometer.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 10:57 am
by StrokerBoy
Yeah, the red warning light comes on at 80kph (50mph) and stays on until you slow down, there's a feed from the speedo I think.

I get a bit of clutch drag sometimes, not really a problem though it's difficult to find neutral again at a stop. Try adjusting it out via the cable if you can.

The growling noise is a bit more worrying. Not experienced it, but sounds like something's got some play somewhere ? There's an awful lot going on inside a KR's crankcases, more so than on a parallel twin. But if it's road-speed related (rather than engine-speed) I'd be looking at the chain/sprockets and maybe wheel bearings. Or maybe the main output shaft bearings.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 12:43 pm
by Gerrit
Re the growl: if you intend to strip the clutch check the ball bearing on the gearbox input shaft at the same time.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 3:53 pm
by pepsi
Gerrit wrote:Re the growl: if you intend to strip the clutch check the ball bearing on the gearbox input shaft at the same time.
Yea I'll have to dig around in there looking for that growl , when swapping out/rebuilding the clutch. Could be another big time project creep. :? The only other thing is to ride it some more and try to narrow down where its coming from , kind of hard to do when you're going down the road. I might try to reproduce the growl on the stand with rear wheel supported, it gets scary when the wheel is spinning so fast. :shock:

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 7:58 pm
by pepsi
Found the output shaft to have 018" end play. What locates it? Installed a new sprocket but its not too tight either.
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Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 8:19 pm
by pepsi
pepsi wrote:
Gerrit wrote:Re the growl: if you intend to strip the clutch check the ball bearing on the gearbox input shaft at the same time.
Yea I'll have to dig around in there looking for that growl , when swapping out/rebuilding the clutch. Could be another big time project creep. :? The only other thing is to ride it some more and try to narrow down where its coming from , kind of hard to do when you're going down the road. I might try to reproduce the growl on the stand with rear wheel supported, it gets scary when the wheel is spinning so fast. :shock:
Got the wheel going real fast on the stand , pretty scary, no growl observed :? So it might be an " the driveline under a load" thing.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 9:03 pm
by pepsi
Pulled the clutch and I think I found the growl, the clutch basket is rubbing on the inner cover :shock: , but now I have figure out how to fix it. The clutch needs to be spaced out somehow. There is what appears to be a seal between the clutch basket and the bearing. I think its a home made thing . So the question is; is there a spacer between the basket and the bearing? It might be # 92022-1573, its hard to tell from the drawings.


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Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 9:34 pm
by pepsi
the clutch basket slips on the spines nicely but it is kind of loose nothing too bad, that might be the cause of the rubbing. However according the manual it seems that it is supposed to be tight on the splines. Installing it and measuring the recess per the manual , it fits correctly. There seems to no new basket # 13096-1060 for sale anywhere . :?

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 10:27 pm
by Gerrit
According to my parts catalogue (purple cover) for the A2 92022-1573 is a shim on the output shaft. I don't have a KR250A but going by the parts catalogues I have, there should be a shim on the outside of the input ball bearing (92022-1620), then a circlip, another shim (92022-1620) followed by shim 92022-1607. Next comes a bush (92046-1122), the clutch gear slides over the bush. Next comes the clutch assembly. No sign of any seal whatsoever. I'll dig out my shop manual to see if I can find anything further.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Mar 06, 2017 10:54 pm
by Gerrit
Neither my Japanese nor my English manual has a cross-section drawing of the cutch gear and clutch assembly unfortunately, but I suspect that there may be a shim missing behind the clutch gear. The two 92022-1620 shims are 28.3 x 42 x 1.5 mm, the 92022-1607 is 28.3 x 36 x 1.4 mm accordig to the parts catalogues. I leave it to those with superior knowledge of the tandem engine to advise further.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Mar 07, 2017 4:21 am
by pepsi
Gerrit wrote:Neither my Japanese nor my English manual has a cross-section drawing of the cutch gear and clutch assembly unfortunately, but I suspect that there may be a shim missing behind the clutch gear. The two 92022-1620 shims are 28.3 x 42 x 1.5 mm, the 92022-1607 is 28.3 x 36 x 1.4 mm accordig to the parts catalogues. I leave it to those with superior knowledge of the tandem engine to advise further.
thanks, very interesting, something to think about :|

I looked into the 92022 shims a little more, it seems they are located behind the main drive gear, as shown in the drawing highlighted by the red arrows, I need something front of the main gear between it and the clutch basket, see the blue circle, I think I'll machine a spacer to go there to hold the basket away to keep it from rubbing on the inner engine cover.

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Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Mar 21, 2017 5:12 am
by pepsi
The big bearing behind the basket looked and felt/rolled great. The h***a wheels have all new bearings also.

I machined a spacer to fit behind the basket to space the basket away from the inner cover. Got all new friction and steel plates and will putting everything together tomorrow. Unfortunately I cannot test anything until I get it out on the road so it has to be all buttoned up and full of oil. :roll:

Plus I only have one gasket right now. :shock: I think I'll install it without any sealant , so I might be able to reuse it if I have to. Until I can get some more.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Mar 21, 2017 11:16 am
by Gerrit
The clutch basket slides onto the splines of the clutch gear and if all shims are in place then there shouldn't be any contact between clutch basket and casing. If a shim is missing, however, the clutch gear can move too far to the left and thus allow the unwanted metal to metal contact. If the bike were mine I'd remove the clutch gear to make sure the shims are all there, and of the specified dimensions- better safe than sorry, even if it means some extra work.