KR-1S.co.uk Forum

Yes good that you have found what the problem is Stew.
I've got 4 kr engines & yes they do develop play in the bearing area. Its not the bearings themselves but the housings that are a problem. There seems to be some sort of insert in the crankcase cases that houses the bearings that wear oversize so the outer race becomes a loose fit. Also I have seen the inserts themselves develop play. Once you get play the seals are effectively loose on the crankshaft & the oil gets sucked in.
A mechanic I know who used to work on a lot of these krs back in they 80's reckons most of the faults in this area can be attributed to incorrectly set up crank dampers. Seems to make sense that dampers with excess movement in them due to incorrect spring tension setting would cause all sorts of problems. Also the crank bearings are lubed by the autolube not the gearbox oil.
The crankshaft seals on the right hand side of the engine are easy to change & can be done with engine in situ. Left hand seal crankcases have to be split.
The engine on my KR was blown when I acquired it 10 years ago. I used the later cranks with the dampers secured by a nut, new pistons & rings & some very low ks cylinders I got from a wrecker. I spent some time setting up the crank dampers
Bike has now done 10,000ks & hasn't missed a beat -starts within 3 kicks even though sits around for months & always starts 1st kick when hot
Has done return trips from Sydney to Mount Tambourine Qld & back as well as to Healesville Vic & back (VJMC Rallies).
Although bike is in original unrestored condition I was given the annual overall Kawasaki trophy as the judge, a Kawasaki specialist couldnt believe he had seen a KR250 actually running & ridden to a rally!
Let us know when you try a replacement CDI

Good second hand CDI found, received in the mail today, fitted, tested and motor now starts very easy and is running SWEEEEET. Well except for all that excessive smoke from the rear cylinder/ top exhaust pipe. Dam it. Now looks like the next step is engine out, strip down and replace the crankshaft seals.

nigb wrote:Yes good that you have found what the problem is Stew.
I've got 4 kr engines & yes they do develop play in the bearing area. Its not the bearings themselves but the housings that are a problem. There seems to be some sort of insert in the crankcase cases that houses the bearings that wear oversize so the outer race becomes a loose fit. Also I have seen the inserts themselves develop play. Once you get play the seals are effectively loose on the crankshaft & the oil gets sucked in.
A mechanic I know who used to work on a lot of these krs back in they 80's reckons most of the faults in this area can be attributed to incorrectly set up crank dampers. Seems to make sense that dampers with excess movement in them due to incorrect spring tension setting would cause all sorts of problems. Also the crank bearings are lubed by the autolube not the gearbox oil.
The crankshaft seals on the right hand side of the engine are easy to change & can be done with engine in situ. Left hand seal crankcases have to be split.
The engine on my KR was blown when I acquired it 10 years ago. I used the later cranks with the dampers secured by a nut, new pistons & rings & some very low ks cylinders I got from a wrecker. I spent some time setting up the crank dampers
Bike has now done 10,000ks & hasn't missed a beat -starts within 3 kicks even though sits around for months & always starts 1st kick when hot
Has done return trips from Sydney to Mount Tambourine Qld & back as well as to Healesville Vic & back (VJMC Rallies).
Although bike is in original unrestored condition I was given the annual overall Kawasaki trophy as the judge, a Kawasaki specialist couldnt believe he had seen a KR250 actually running & ridden to a rally!
Let us know when you try a replacement CDI

Ok, just to clarify is the RHS the side with the kick starter that the crank seals can be changed with the engine in the bike? I will give that a go first if Yes and check for crank play and then determine if I have to go any further. just trying to avoid a full strip down if possible.
Thanks Stew.

Yes that is correct Stewart. Also you can check crank play on that side of engine whilst it is stripped down that far. Take note of rotary valve/crank damper timing section in manual before you take it apart. Not at home until Sunday night but if you want to wait I will measure seal dimensions for you. Also check damper spring setting too whilst you have it apart. I use a large nut & bolt with washers to compress damper & remove circlip safely. Good to hear cdi replacement worked.

One other thing my kr smokes like crazy when I start it. Just running engine in driveway doesn't seem to clear it very quickly.. However if I ride it 2-3 ks down the road smoke clears to nothing.I think when bike sits for a while oil from the auto lube drips into the intake then burns when started as it is not mixed with fuel.

Hi nigb, thanks for the information. I spent today working on some of my bikes and the afternoon on the KR. Removed top pipe and cleaned all the oil out and put it back together to see if that would help, was a long shot and no it didn't help.

Took your advice nigb and removed clutch cover and clutch. Removed carburettors etc... bolts from RH cover and tried to remove it couldn't get the dam thing of. WHY? any ideas please. Is it extremely hard to remove the cover due to the bearings of something like that?

Help and advice needed please.

Cheers Stew

Both cranks are supported on the rh side by bearings on the A 1 models not sure if the A2 these tend to stick in the cover you are trying to remove, I had to run a tap down a couple of the cover bolt holes and use larger bolts to push the cover off

Thanks for the info. Will try that.

There are a couple of dowels locating the cover too which adds to the problem. I'm not sure but I think moving the clutch actuating arm pushed the cover off.

Oops sorry Stew misread your post when I saw right hand cover I thought you meant clutch cover.
Yes the right hand case can be hard to get off. Dougs idea a good one although I have never tried it. I Will have a look at my dismantled engines tonight & see if I can remember how I got mine apart

Hi all, no chance of getting out to the bike today. Combination of work and bad weather prevented me form trying to get the RH case of the clutch side of the engine.
Will try to get some time this week and will post up the outcome.

Thanks nigb, I will be waiting on any further advice from you or anyone else.

Cheers to all giving advice, much appreciated.
Stew

Stew I cant remember how I got cases off. Looking at one of the cases tonight I notice one dowel pin is slightly down to left of oil filler plug & the other slightly down to right of oil level sight glass. If I was applying pressure I would do it at these points. You might even be able to start moving it using a bit of leverage through filler plug hole with something soft like plastic or wood that wont damage anything.

There are quite a few pictures of case removal on this web site. Might be useful?

http://motor.geocities.jp/tetsuma3ya/

Thanks guys for all the tips, tricks and advice.

Tried getting the side cover of today:

First attempt was unsuccessful by refitting the clutch and cover and pulling the lever and hoping the side cover would come of.

Second attempt also unsuccessful tapped out TWO holes in cover to fit larger bolts in cover and to use them to push against the casing. No way will it move.

Third attempt, Tapped TWO more holes (Total of four now) Got extra bolts original thread size cut screw driver slot in them and cut the heads of the bolt and then screwed them into the casing to stop the larger bolts damaging the crank case, fitted them and screwed in larger bolts and tightened and tightened them way to tight for my liking. STILL NO MOVEMENT well just a tiny bit. Used a pin punch on the outer bearing housings to get them to move in the side cover. After bashing the you know what out of the bearings, I made some progress. Repeatedly tightening the large four bolts and belted bearings, HORRAY the cover was OFFFFFFFFFFFF WOW after three and a half hours of thinking you have got to be joking this just ant working. "I WIN" =D> =D>

That was most of my day today. Slow and painful but a success in the end. I hope this bike is worth all the blood , sweat and tears in the end.

Now that I have the Cover of the bike I will need some gaskets. I am In Australia, anything local? where is the best place to get 1985 KR 250 A2 engine gaskets? I need the gasket for the RH side cover that fits to the engine case gasket, clutch cover gasket, the two rubber seals for the rotary disc housings to cover.

Think that's it. Any advice would be appreciated.

Thanks Stew