KR-1S.co.uk Forum

Hello all. Today I aquired a 1984 KR250A tandem + an incomplete spares bike. The "good" bike will start but will only run for a few seconds before it dies. Appears to be fuel related as it will continue to run if ether is sprayed down the filter intake boots. However... fuel does appear to be reaching the float bowls so am somewhat mystified. At this point am wondering if it could be due to bad/old fuel or perhaps blocked jets but I'm sure you lot know a lot more about these bikes especially as this is the first 2 stroke I have owned in many years.

Alwyas a good idea to drain the old fuel, clean and check the settings on the carbs, then add some nice fresh 95 or 98 octane to the tank.

PS. Welcome to the forum mate.

Hello Scotta KR, will try a bit of fresh juice in the next day or two and hopefully the beasty will be more inclined to play the game. Thanks for your response. Incidentally what plugs would you reccomend for one of these?

Try here http://www.kr250.org/KR_home.htm for service info. May help get it up and running.

As ScottaKr says, nice fresh fuel can't be beat. Also try running it with the fuel cap open as a blocked breather on the cap itself can cause this problem.

And welcome to the forum fella.

Thanks again for the further tips. Will try them all. Also, when I go to the manual at the top of the page this appears to be for the parallel twin, but are the carbs the same? Or is there something for the tandems here that I'm missing? Have a couple of jobs I have to do on the CX500 that is my current transport today and also a federal election to vote in here in Oz today. Will it be the scarecrow with the big nose or the tinman with the big ears? Have a good day {night?} and I'll get back later. Cheers.

Yeah, the manual at the top is for the KR1, and the carbs are very different.
If you ask Tim (A.K.A. StrokerBoy) he may be able to help you out with a PDF copy of the correct manual.
If there's any specific details you need in the meantime, just ask and I'll reference my manual for you.

Hi again. Little progress made today. About the only thing I've learned for sure is that the problem isn't the fuel tank breather. Have removed and partially dismantled the front carb,-no obvious problems though a few drops of water appeared on the bench top. Float not jammed or anything stupid like that. Screw that holds the float needle seat in place is rusty suggesting a damp environment over a period of time though don't know how significant this is likely to be. Main jet is clear, slide not jammed. Reassembled, refitted with remote fuel supply and ran with no rear plug fitted,- spark tester fitted to lead. Still the same result but is definitely not a spark problem, this thing has one of the healthiest sparks I have ever seen/heard. Time to ponder some more I guess but like many of these things it will probably turn out to be something stupid! [-o< A carbon clogged exhaust couldn't shut a motor down this quickly could it?

Have tried threatening this mongrel of a thing with being parted out and still it refuses to play the game.

when I got mine after cleaning the carbs up etc it would do the same and I found the pilot jet in one carb kept clogging up almost straight away. So after a few rip and strips now its sweet. Must have been some residue in the fuel line.

CXPHREAK wrote:this thing has one of the healthiest sparks I have ever seen/heard.

you know the smaller and the "blue-er" the spark is, the better ? and a spark that makes a big clear light is ready for the dustbin ?

just to make sure

O.K., thanks for those 2 answers. First off I still tend to think my problem is fuel so will try a more thorough clean out. Secondly, I do not fully understand Janbros post about the spark. The spark at the plugs looks pretty normal but with my spark tester you are looking for a minimum of 5 mm and 10mm is supposed to be very good. also the spark is blue and crisp. Thank you. =D>

Make sure you remove the smaller jet behind the main jet. Clear it out with a small wire from a wire brush, then carb cleaner... A needle is too big to go through it. I just had this problem and missed the smaller jet. The bike runs perfect now! Thanks to all the guys on this forum who gave me support for my ride!

CXPHREAK wrote: Secondly, I do not fully understand Janbros post about the spark. The spark at the plugs looks pretty normal but with my spark tester you are looking for a minimum of 5 mm and 10mm is supposed to be very good. also the spark is blue and crisp.

so your spark is good.

I've often found out that people thinck that the more light a sperk gives, the better it is, but it's just the other way round , that's all I was traing to say

O.K., thanks for the clarification Janbros. If all goes to plan today I should actually get to have abetter look at the animal. Have a good one.