KR-1S.co.uk Forum

Took the old girl for its first proper blast today...

Firstly i scooted around at low rpms to let her warm up and once up to temp opened the throttle fully, at first she wouldn't pull and instead bogged down and sounded like crap (almost knocking and rattling).. after and few attempts she seemed to clear up and pulled to the red in every gear without issue.. however it didnt seem to have the sudden burst at the top end i remember it having.

Anyway during the ride i ended up in traffic, once out the traffic i attempted to open her up only to find her bog down again, whilst not as bad as the first time she cleared up and went ok.

After being left to cool for 4 or 5 hours i took her out for another blast .. same problem .. bogs down badly then clears up.

SO any ideas ? .. im thinking maybe an exhaust decoke maybe needed ? reeds ?

To rule out a few things i have :-

Cleaned and gapped plugs.. however ill admit they arnt new.
Cleaned carbs and jets and set float heights
Balanced throttle slides
Set the air screws to 1.25 turns out
Checked kips adjustment , however the links are very sloppy on the left hand cylinder

Many thanks for any help in advance.

what miles are on the pistons/rings. could be a bit tired? maybe needs ex decoke. does it rev on still, just not pulling as strongly as a fresh motor? they all bog/develop a flat spot after very steady riding when giving it the berries for the fiorst time once the road clears. once its cleared its throat it should pull through the range flat spot free.

sounds ok to me..mine has done exactly the same for 12 years.....always cough's splutter then WHOOSH...let it sit for an hour and it needs a clear out again...but as for no rush of power worth setting the valves properly....and deffo go for a new set of plugs for the sake of a tenner br9es for kr1 and br10's(br10eix) for a kr1s....

well i think my problems been solved .... i think that i didnt get the carb sync perfect the first time round however instead of removing the airbox i just pulled the filter and mesh and used a mirror and torch and got them balanced spot on, this improved matters but still not perfect so i pulled the slides and dropped the needles so the clip is now on the second groove from the top and gapped the plugs to 0.7, result ? pulls all the way to the red with no holding back after slow running and much crisper to boot and almost eliminated the nasty KR1 7K flatspot

Thanks for the help all