KR-1S.co.uk Forum

i was browsing yahoo japan and came across a brochure for a kr250s.
whats the difference between this and a normal kr250 ?

The 'S' has a powervalve set up in the barrels/head. It's called KVSS (not KIPS) - Kawasaki exhaust Valve Synchronisation System. Doesn't add anything to top-end power, just fills in the midrange.

That's the main difference, other than the paintjob and fairing-mounted mirrors it's the same as the ordinary one. Rare though - I still don't have one (yet).

Found this nice original KR250S for sale, fair price too. Trouble is, it's in California. Anyone wanna lend me a van with, erm, wings...


More pics/details available HERE.

I've managed to get hold of a pair of 'S' barrels complete with powervalves, servo and linkages.

They're a bit dirty but should clean up OK. Everything moves as it should. Can't see any damage.

Sadly I don't have the head or the control box so I can't just do a quick transplant. If anyone can help you know where I am.

I'm ssooooooooo jealous!

This is the first time I've ever seen 'S barrels
Is there any difference in the port layout?

StrokerBoy wrote:I've managed to get hold of a pair of 'S' barrels complete with powervalves, servo and linkages. Sadly I don't have the head or the control box so I can't just do a quick transplant.

Not much chance of finding just a 'S' head for sale is there ?

Wrong ! Spotted one on Yahoo Japan and won it for 900 Yen (less than £5) !

It came with the balance pipe too, though I still don't have a control unit to operate the servo, and I've just realised that the 'S' exhausts might be different too 'cos the barrels are a different shape. All jolly interesting though innit ?

My guess is they're the same pipes, I've the the same numbers stamped on all of mine K102/103. You should be able to tell if you offer up the different barrels to each other on a table and use some sort of measuring block. Are the part numbers the same? And also thats a sneaky way of getting a 250S.

They dont look as if they have been worked very hard. Clean & fit.!......... Whats the best way to access yahoo auctions Japan. When I try the first page is English/Japanese soon as I try to move anywhere on the site I get Japanese only ? Alan.

There are some tools that let you translate foreign-language web pages (eg. BabelFish) but I must admit I just read them in the native Japanese, as much as I can anyway. You'll need to use some kind of middleman/agent (eg. ok!shon) to do your bidding for you too.

You can read Japanese I'm surprised the Japanese can read it

corvine wrote:My guess is they're the same pipes, I've the the same numbers stamped on all of mine K102/103. You should be able to tell if you offer up the different barrels to each other on a table and use some sort of measuring block. Are the part numbers the same? And also thats a sneaky way of getting a 250S.

Good thinking Mick - it never occurred to me to check the partnumbers...

I have now though. They're the same. So not only are the mountings identical but so are the internals.

StrokerBoy wrote:The 'S' has a powervalve set up in the barrels/head. It's called KVSS (not KIPS) - Kawasaki exhaust Valve Synchronisation System. Doesn't add anything to top-end power, just fills in the midrange.

That's the main difference, other than the paintjob and fairing-mounted mirrors it's the same as the ordinary one. Rare though - I still don't have one (yet).

was it only s models that have fairing mounted mirrors? Found one i think..[/img]

scott.n wrote: was it only s models that have fairing mounted mirrors? Found one i think..[/img]

No, the later KR250 also got the fairing mounted mirrors, so you can't tell just by that.

scott.n wrote:was it only s models that have fairing mounted mirrors? Found one i think..

No. After 1985 ordinary non-S models had fairing-mounted mirrors, possibly depending on which market they were sold in. Only looking at the LHS top-end of the motor will confirm an 'S'.

I'm not updating this thread for any special reason. It's just that I took a couple of pics of my KVSS top-end at the weekend and thought it might help illustrate the differences from the normal model, for all those of you who think you've spotted an S for sale. [-o<

Pics are taken from the LHS, and clearly show the fat metal pipe that connects the extra chambers together in the heads. Below that, the round thing bolted to the front cylinder is the servo motor that has a linkage to each of the butterfly valves in the exhaust ports. That wire leads to the servo control box, which is the only part of the jigsaw (apart from a head gasket) I don't have yet.