KR-1S.co.uk Forum

Hi Martin I can’t believe I’ve come this far with my rebuild just to flip up AGAIN but this time with theoriginal pistons and rings I’ve decided to used during the running in period and save the Mitaka pistons for another day.

I was trial fitting one piston with rings fitted in the bore in the kitchen (nice and warm ) when I lost my balance stuck my arm out to save my face and in doing so pushed and twisted the piston into the barrel where it stopped halfway up the bore.Now I cannot remove it as a ring or rings have hit a port edge and ridden over the pins.I can rotate the piston about 25 degrees and down the bore about 30 but after 4 hours of trying I can see no way to get the piston out of the cylinder without damaging the piston and probably the bore.

Any one done this themselves or am I the only idiot on here?

Need all the help I can get with this problem fella.
Regards
Col

Would of been happy to of rebuilt your engine for you.

To save problems.

I only say this as you have posted quite a lot.

Am also happy to give you my number and talk you through engine problems

If the piston ring has snagged in the exhaust port (the most likely scenario given its width) it should be possible to carefully push it back into its groove while pushing the piston down (or up). You will probably require an extra pair of hands for this, however. The boost transfer portis too narrow to cause the problem. Do you know whic port has trapped the ring?

Hi Gerrit thanks very much for your info on my problem.That other pair of hands doesn’t exist unfortunately so with your words in mind I spent another two hours trying to stop the barrel rolling around on the kitchen worktop and with one set of fingers down the bore and locking the end of the top ring managed to twist the piston a little and gently pushing down The piston released down the bore and out !! Thank you God of Strokers.
Regards
Col

ME !
i've owned my Kr-1 b2 from new (August 1989) and after 16000 miles the original pistons and rings are still going strong, found out on here though that the later b2 motors had upgraded rings like the Kr-1s that don't self destruct so i'm guessing that my bike had these fitted at the factory.

Hi Pookie thanks for the reply and I believe now that after buying a new set of “hens teeth” std size kr1 rings to fit on my old pistons that my pistons although marked B are Kr1s pistons because the ring end ground profiles are not the same as my originals and the pistons won’t go in the bore fitted with these rings.I’ve had the bike 25 years and not had it on the road as it was bought damaged and only had 9000 miles on it one girl owner who lost her lower leg in the accident poor thing So I guess it went back under warranty to replace the pistons with the fully shrouded ring type and somewhere along the line it gained an s clutch casing 6 bolt hole clutch cover which has caused me some texting embarrassment also.
I will run in the rebuilt crank with the original pistons fitted then maybe fit the new Mitaka’s I bought when the crank was being rebuilt.Hate to see them sitting in the boxes on my kitchen table .yes ypu guessed it I live alone so I can bung the carbs in the dishwasher without some Doris giving me grief over it .

Be very careful with aluminium parts in the dishwasher, very often they tend to react with the caustic salt and go black.

Also, Martin has very kindly offered to pass his number onto you, there’s no doubt Martin is a very accomplished engine builder and his advice would prove most valuable!

Hi Paul I replied to your post yesterday and the postie rang the bell so I clicked save as a DRAUGHT came back to add abit more text but for the life of me I can’t find how to find the DRAFT message and to send it.any info on this please?
Col

Hi Col it’s as easy as clicking the relevant box at the bottom of the reply window (next to where you clicked save draft) then selecting the draft required from saved drafts

Mitaka ones are the old k design not the latest enclosed ring k design
No idea about wiesco as I still run latest k pistons as you can still get new rings

Hi fella thanks for the reply and the info.Had another look just now at the Mitaka pistons I bought this year and it looks like the rings do enclose the ring pin and the ring set has DT 125 stamped on the box and are Riken so looks like I’m safe if I fit these after a little running in on the rebuilt crank with the old original S pistons.
Col