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Re: KR250 growly symptoms, maybe the clutch ?

Posted: Sat Mar 25, 2017 12:39 am
by pepsi
JanBros wrote: Sat Mar 25, 2017 12:17 am you know a circlip has a direction ? it can be mounted the right way or the wrong way.
they are made by stamping and because of tha, they have e side with sharp edges and a side with rounded edges.
the sharp edge must always be placed to the outside (as in the side to which it might be pressed of. sometimes that's inside).
It wasn't me! :shock: There is no damage to anything I can see, gear teeth,bearings shafts , nothing. weird. Everything is like new.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Sat Mar 25, 2017 5:36 pm
by pepsi
I think the growl might be coming from the rear wheel or cush drive and will investigate it.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Sat Mar 25, 2017 9:26 pm
by pepsi
pepsi wrote: Sat Mar 25, 2017 5:36 pm I think the growl might be coming from the rear wheel or cush drive and will investigate it.
I might have found the growl :-| , as it was speed related I am hoping the clearance between the sprocket bolts and the wheel were too close. With the new rubber dampers in the wheel , the clearance might have closed up under a load then reopened after slowing to a certain speed. I shortened the bolts. I wont know if it is fixed until I get the bike back together. Here's some before and after shots.

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Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Mar 28, 2017 4:44 am
by pepsi
JanBros wrote: Sat Mar 25, 2017 12:17 am you know a circlip has a direction ? it can be mounted the right way or the wrong way.
they are made by stamping and because of tha, they have e side with sharp edges and a side with rounded edges.
the sharp edge must always be placed to the outside (as in the side to which it might be pressed of. sometimes that's inside).
On this snap ring/circlip the question is, what direction is the trust directed ? :shock:

I am still baffled on why these mangled parts got all mangled without hurting anything else. Were all the messed up gears and such replaced but the mangled shim and snap ring left? Very unlikely :shock: I am guessing an assembly error , the offending two rings fell off somehow , and when the main gear was installed it went without them, but they were left inside that area . They couldn't migrate from another area the oil holes are too small . It is still a stretch because of no damage! . :shock:

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Mar 28, 2017 10:29 pm
by dougindoors
When I stripped mine these shims were missing , I had to get new ones made, check my thread "finally started" the-parts list gives you all the size you need.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Mar 28, 2017 10:39 pm
by dougindoors
Pepsi....frame should be back tuesday 21st will post pics, engine has been stripped and partially rebuilt, thats when the problems started. bolting the 2 half's of the crank cases together i noticed the cap head bolts were up to torque but not holding the cases together, bolts to long? streched? well out they come again grind off 2mm clean off sealant and refit bolts,now the fun starts, were did i put that shim for the kick start idler gear and the shims for the crankshaft centre gear? ](*,) oh! some one didnt fit them last time the engine was stripped. well back to the local friendly engineering shop, 1x 1mm 2x 1.5mm 1x 1.4mm shim and so on hopefully end of next week the engine will be rebuilt. pics to follow
By the way Tim thanks for the manual all those years ago lol. without it i would be knackered, i will give you 1st pickings on all the spares l have over when she's finished. O:)

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Wed Mar 29, 2017 1:56 am
by pepsi
dougindoors wrote: Tue Mar 28, 2017 10:39 pm Pepsi....frame should be back tuesday 21st will post pics, engine has been stripped and partially rebuilt, thats when the problems started. bolting the 2 half's of the crank cases together i noticed the cap head bolts were up to torque but not holding the cases together, bolts to long? streched? well out they come again grind off 2mm clean off sealant and refit bolts,now the fun starts, were did i put that shim for the kick start idler gear and the shims for the crankshaft centre gear? ](*,) oh! some one didnt fit them last time the engine was stripped. well back to the local friendly engineering shop, 1x 1mm 2x 1.5mm 1x 1.4mm shim and so on hopefully end of next week the engine will be rebuilt. pics to follow
By the way Tim thanks for the manual all those years ago lol. without it i would be knackered, i will give you 1st pickings on all the spares l have over when she's finished. O:)
Boy I just read through your thread, wow :shock: and I thought I was going through the tandem ringer! After I read it I began to wonder about my pinion splines to crank splines fits , they feel very nice with just very little play, I could throw an indicator on them but I am thinking just enough to feel maybe .001-.002"? You would think the dual gear main clutch gear that ties them together with its offset gear teeth and damper would pull that tiny slop out of the gear train? Here's a movie, probably cant see enough to say. I am waiting for snap rings and some other parts so I'm just staring at it for now.
https://youtu.be/pSoj1QaSYxI

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Wed Mar 29, 2017 2:00 am
by pepsi
I'll put a dial indicator on the pinions to see exactly what the spline clearance is..... Tomorrow and make another better movie. :roll: Any guesses? :lol:

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Wed Mar 29, 2017 10:42 pm
by pepsi
Looks like my guess was low, :| .010" on the front and .006" on the rear splines :shock:

https://youtu.be/0-_DEjJ88RY

https://youtu.be/haLW9wzP_2M

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Thu Mar 30, 2017 2:49 am
by pepsi
Now I am wondering if the misalignment of the punch mark and hole( that I corrected)on the front pinion was something arranged from the factory to compensate for a slight factory spline fit mismatch?

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Fri Mar 31, 2017 9:32 pm
by pepsi
I investigated the front pinion fit further. When I pull the pinion off the crank still engaging the splines, the pinion is now engaged with splines on the crank that the pinion does not normally ride on. It is observed that there is much less play, about .006" on that area . Which leads me to believe the difference is crankshaft spline wear. So there is .010" movement on the worn crank spline area and .006" on the unworn crank spline area ( not considering the pinion female spline might have wear also), that leaves a .004" wear total. That seems a pretty small number, however I have no reference to what is acceptable. Without a microscope I see no wear patterns on the crank splines. :|

Does anybody have fresh parts to check?

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Sun Apr 02, 2017 11:30 am
by dougindoors
You will who if they are worn as the engine will sound like a bag of nails on idle or below 1500rpm, as you increase the revs the noise will go. So if it doesn't rattle on idle don't worry t doesn't affect the running just dammed annoying. I tried loctite 660 without success, it's the spines that wear not the dampers, I had a quote to redo the splines on the crank, ouch! So I bought a pair of A2 cranks from Aus. Just got to fit them now.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Sun Apr 02, 2017 3:43 pm
by pepsi
dougindoors wrote: Sun Apr 02, 2017 11:30 am You will who if they are worn as the engine will sound like a bag of nails on idle or below 1500rpm, as you increase the revs the noise will go. So if it doesn't rattle on idle don't worry t doesn't affect the running just dammed annoying. I tried loctite 660 without success, it's the spines that wear not the dampers, I had a quote to redo the splines on the crank, ouch! So I bought a pair of A2 cranks from Aus. Just got to fit them now.
Hi, It does not sound bad at idle , so it will go back together as is and hope.Right now I'm waiting for a gasket set from Japan . I would be interested if you could throw an indicator on yours to see what the clearances are.

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Mon Apr 03, 2017 6:59 pm
by pepsi
you can plainly see the wear on the splines on this crankshaft.

http://page13.auctions.yahoo.co.jp/jp/a ... r175425284

Re: KR250 growly symptoms, maybe the clutch ?

Posted: Tue Apr 04, 2017 4:05 am
by pepsi
took some photos, use the manual to understand the arrows.

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