KnallertForum.dk

Hope you guys can read English better that I read Danish (not at all)
Spec: 47.6 bore 39.7 Stroke.

I know i have seen that one before.. are you on fs1e.co.uk ?
btw nice engine

Yeah thats me I'm an attention whore, here,s the clip of it running before I got the cooling system on.

Sounds great.

How did you mount the cylinder to the crankcase ?

I originally had the cases modified to accept a Yamaha YG1 cylinder which worked ok but was having heat problems.The stud spacing for a YG1 is 50mm same as most of the modern mopeds so this cylinder fitted fine as it's for a modern horizontal Minarelli engine I think it's going to be good for 80mph or more when dialed in right.

ok, thanks

I think it's basically the same as the one i am (or rather was) building, it required a lot of welding on the cases to make the transfers big enough to fit a modern minarelli cylinder. Also mine has a rotary valve in the "wrong side" (ignition side) much the same as in the old Kreidlers.
It has been sitting on the shelf in the workshop for some time now, but maybe someday i will have the time to finish it.

Yes, you're right about a lot of welding,had to have a gasket surface welded and machined onto the righthand case to have something for cylinder to seal on.I'll find out some pics when I get a chance.

Did a bit of road testing on Friday after retarding the timing off and got a video clip for you. Noticed power has dropped off quite a bit so will be advancing it a bit now.

Had the bike on the dyno a few weeks ago, here's the results not quite what I'd hoped for but not bad for a 70cc motor,I've copied this from the UK FS1E site, posted by 50ccTuning the man with the dyno


Heres the dyno graphs for flika,s 70cc lc special the mk2 motor has broke the 18bhp barrier and with the right pipe combo would have broke into 20bhp
we are busy plotting the mk3 motor which is the ultimate fs1 crankcased motor
blue is first test where i explored its 15000rpm overrev potential hitting 70mph in 4th (5speed)
red is after setting up without overreving it i shut off early
this graph is horsepower versus speed as the rev counter didnt pick up a clean reading on the day