1990 KR1S Overhaul - what to do?

[Ryza]

Hey everyone!

I was wondering if someone would be willing to share their knowledge with me, i've just recently purchased a 1990 KR1S not running with a bung cdi, to fix this, replaced it with a KR1 unit and now its running, after fixing a few exhaust leaks its alot smoother but (in controlled conditions...... ) i can only achieve a top speed of 160 - 170 and its running out of puff, was told this should be around 200 as they are rumoured to produce close to 60hp, this bike has had a recent rebuild so the bores and pistons are mint az

does anyone have a list of what things i should look at first

so far it has fresh gearbox/engine oil, gas, battery

its not the cdi is it? i was told originally that the only difference between a KR1 and KR1S was the carbs and exhaust, any info much appreciated

i've got alot of time to fiddle with this bike as i've aquired a broken collar bone from, lets say, friction co-efficient testing with mother earth, stupid dirt bikes, should have kept to the road :angry:

thanks alot

[Mr. Peanut]

Check that the powervalves are operating. Sounds like they might not be opening.

[CM2005]

fark, lucky guy!! got any spares!? ther differences, are KR1 has ridged frame beams, 3spoke wheels, and the rear shock isnt adjustable.. Yay Kwakka 2 Strokes!

[Dafe]

Thought Crasherfromwayback would have posted by now. He must be getting pissed.

The KR1's are reknowned for a few problems which thankfully are easily fixed...
Just give it to me.

[FROSTY]

Definitely try the power valves.

[Ryza]

power valves are a-o-k btw, tho rev counter doesn't work, maybe not keeping in power range?

[dickytoo]

Thought Crasherfromwayback would have posted by now. He must be getting pissed.

The KR1's are reknowned for a few problems which thankfully are easily fixed...
Just give it to me.


I have it on good authority that crasher caused most of the known problems on KR1s - they were all perfectly ok until he got his hands on them:D:clap::rofl:

[CM2005]

power valves are a-o-k btw, tho rev counter doesn't work, maybe not keeping in power range?

try KR1S.co.uk (http://www.kr-1s.co.uk/)... they're really helpful.

[CM2005]

from what i've read, they'll pull from about 6'500, to 11'000... u should be able to keep it in there.. has it still got original airbox? has the gearing been changed? has the porting been altered?

[Ryza]

from what i've read, they'll pull from about 6'500, to 11'000... u should be able to keep it in there.. has it still got original airbox? has the gearing been changed? has the porting been altered?


original bike as far as i know, i've just remembered that the last owner might have fiddled with the carbs, in this case i should get the carbs balanced again right? anyone suggest a place to go in the waikato?