KR-1S.co.uk Forum

well she lives, but alas some funny noises from the clutch/ rear damper area, almost like a knocking rattling was gonna rip it apart again but just had a thought i have not balanced the carbs yet. had similar noises from multi cylinder 4 strokes when the carbs are out, it only makes the noise at low rpm under 1500 rpm or on a sort off idle once you rev it or hold at 2000rpm + the noise goes, any ideas?

My thought too Doug. There's a lot of cogs whirring about in there with potential lash in each meshing, so if one pot is trying to pull the other one along it could account for it. Surprising how much difference this makes on a 4-pot diesel as you say. Worth a bit of fettling before you pull it apart anyway.

Of course, you might have just missed some crucial part out...

StrokerBoy wrote:My thought too Doug. There's a lot of cogs whirring about in there with potential lash in each meshing, so if one pot is trying to pull the other one along it could account for it. Surprising how much difference this makes on a 4-pot diesel as you say. Worth a bit of fettling before you pull it apart anyway.

Of course, you might have just missed some crucial part out...

well nothing left out, but found rear rotary disc has had a partial pick up and buggered the disc and cover, also front crank mains have developed play not sure if its the bearing or casing.... hey ho out it comes full strip again. needless to say a bit pi***d off,,, all stripped ready to pull out now i can sleep tonight

dougindoors wrote:

StrokerBoy wrote:My thought too Doug. There's a lot of cogs whirring about in there with potential lash in each meshing, so if one pot is trying to pull the other one along it could account for it. Surprising how much difference this makes on a 4-pot diesel as you say. Worth a bit of fettling before you pull it apart anyway.

Of course, you might have just missed some crucial part out...

well nothing left out, but found rear rotary disc has had a partial pick up and buggered the disc and cover, also front crank mains have developed play not sure if its the bearing or casing.... hey ho out it comes full strip again. needless to say a bit pi***d off,,, all stripped ready to pull out now i can sleep tonight

or do i pull the plug break her and cut my losses

dejavu

Don't know the part numbers for the KR250 but I'm sure it's very similar to the AR125 engine and the Disk Valve in your picture looks exactly the same.

AR disk valve part numbers:
12001-1063 for 22 bhp engine
12001-1064 for 12 bhp engine

May give you another source of replacement disk valves if they are the same?

If this is of interest then
Post a clearer pic with some sizes and I will measure one of my AR disks

well so far as the rh sde is stripped, front crank bearings have play allowing oil past seals, ( missed that dont know how) i should have just replaced all the bearing last time as for the rear rotary valve it has picked up on the outer edge and warped slightly cutting into the outer disc cover. off to my local precision engineering company to machine the cover flat and mill the recesses back in. Gonna try the AR125 disc trick as noted on Tim's site, ordered 2 12001-1063 discs., just hope it works, [-o< this time all the bearings will be changed, lesson learnt "dont cut corners on a KR it ends up messy" and its nothing to do with the 16" front wheel. lol

dougindoors wrote:well so far as the rh sde is stripped, front crank bearings have play allowing oil past seals, ( missed that dont know how) i should have just replaced all the bearing last time as for the rear rotary valve it has picked up on the outer edge and warped slightly cutting into the outer disc cover. off to my local precision engineering company to machine the cover flat and mill the recesses back in. Gonna try the AR125 disc trick as noted on Tim's site, ordered 2 12001-1063 discs., just hope it works, [-o< this time all the bearings will be changed, lesson learnt "dont cut corners on a KR it ends up messy" and its nothing to do with the 16" front wheel. lol

well the AR125 discs do fit if you turn them through 180 degrees but you do loose some spline contact due to the boss offset, if you try to fit the correct way round, it puts the disc timing out due to the splines not being quite in the right place. 2 stroke institute what do you think??? how far can you advance or retard the disc timing?

Glad the AR125 disks work ok
If the engine is in a normal state of tune I would have expected inlet to open 120 degrees BTDC and to close at 55 degrees ATDC. If your moving the disk on the spline then I would have thought it would be ok to close the inlet at up to 80 degrees ATDC.

As for the centre damper, I would have to have a go with one of my
Old disk valves to see if the damper ring can be removed and reversed to help sort out the offset etc. Also the 82-84 disks dont have the rubber damper.

Your thoughts TSI?

by 180 degrees i meant turn them over the only prob then is the offset rubber boss sticks out to far and fouls the crank dampers. i will get a protractor over the weekend and measure the difference in the opening and closing time of the ar disc mounted the correct way against the kr one and let you know what it is hopefully it will be within tolarance fingers crossed [-o<

for those lucky enough not to have seen this

also ready for paint thats gonna have to wait a while

That's a proper interesting engine design !
Hope the build goes ok

Top-shaggy wrote:Glad the AR125 disks work ok
If the engine is in a normal state of tune I would have expected inlet to open 120 degrees BTDC and to close at 55 degrees ATDC. If your moving the disk on the spline then I would have thought it would be ok to close the inlet at up to 80 degrees ATDC.

Your thoughts TSI?

Yep that's where the party is starting. Just wish KHI continued with this engine, even KR-1 cylinders on this bottom end would make a awesome bike.

just a few pics to show that the kr was not your normal mass produced bike, the welding and castings on the frame were a bit of a work of art, the welder must have got a full bowl of rice that day, unlike the stuff that comes out of china

progress, well not a lot, since last post 2 weeks holiday, a few bikes in and out. purchased 2 rotary disc's and covers, oil pump and got the cranks and gearbox mounted in the LH crankcase. now just building the enthuisiasm (think thats how its spelt) to warm the other half on the oven to put it together. hope the wifes not reading this!!!

Doug just been reading your earlier post re low rpm rattle.When I rebuilt my 1st kr motor it had the same rattle & symptoms. After several attempts I traced it to the damper where it sat on the crankshaft spline. I tried some loctite spline repair which quietened it down but not for very long. In the end I rebuilt the cranks using the splines & modified dampers from the later engine . The rattle did not affect performance but was just annoying.
I have 4 kr engines (3 in pieces) & I notice that the earlier cranks seem to wear more in that area. A mechanic I know who worked on a lot of KRs reckoned the crank problems (brgs etc) were due to the dampers not being kept in spec with the manual.
The KR is a great bike & mine has been ridden from Sydney to Brisbane & Sydney to Melbourne & back (over the Snowy mountains) to VJMC rallies without missing a beat.
My next project when I get time is to assemble an engine with some KMX pistons I have modified.