KR-1S.co.uk Forum

how are the engines coming along? really interested in how the other barrels can improve performance

very interesting. When will you get this in and on the dyno?

Finally collected two finished engines of Graham File . Both engines fully rebuilt with tz250 cylinders . One engine is on standard stroke and the other is on 54.5mm stroke . Has taken a while to get to this point but is largely down to me changing my mind on what cylinders to fit and how . Both engines are fitted with 58mm yz125 pistons . Graham has done a brilliant job on both from what I can see so far , just need to get them fitted and on the dyno !!

curious as to what horsepower they will make.

how did he stroke the crank ?

Im hoping to get the 54.5mm stroke engine on the dyno in early new year and the other engine probably a bit later . I sent my crank and crank cases to a company called Crankworks in the USA who did all the work to stroke the crank to 54.5mm . You will find them on Google . I will post some pictures of the work Graham File has done soon .

awesome sums that up Brings a tear to my eye such beauty, glad I only have done a pretty standard restore, bloody AWSOME WORK CAN'T WAIT TO HEAR IT ON YOU TUBE

Fantastic project, is the plate between the barrels and the crankcases a removable adaption plate?
Did you consider any other top ends? KDX200 etc?

Keep the photos coming

The plate is just a spacer plate and slides on the original stud positions , it should also help stabalise the crank cases under load . I will post some more pics of the engine build . I was going to use TZR250 3MA cylinders on one engine and yz125 cylinders on the other and even got the cylinders welded and machined so they would drop on the kr1s cases but then came up with the idea of using the tz250 cylinders and spacer plate . If anyone fancies trying these cylinders please call me on 07770 552666 .

Awesome stuff!

I see they are early 5ke cylinders! They run a 54x 54.5 bore and stroke as standard don't they? So is one engine running 50.6 mm stroke with 5ke barrels or are you running 4dp cylinders on the shorter stroke engine? Just curious that's all.

Dan

Hi yes im using tz250 5ke cylinders on the long stroke engine and 1994 tz250 4dp cylinders on the standard stroke so well spotted . Some pictures of the engine build to follow .

Do you have any calculated bhp figures, or expectations?