KR-1S.co.uk Forum

Hi,

Started the bike today and it is becoming more noticeable a knocking noise from what seems like lhs cylinder area. When it was warming up it seemed the knocking side was warmer to the touch than the rhs. It has trans oil and 2 stroke. Bike has 14,600 miles and I have no idea of rebuild history (probably only thing i havent done to it) Any idea what the knocking would be ? its like the sound of hitting an old fashioned typewriter key only speeded up about 10 times Thanks for any help.

Here is a video which might give a better idea of what i mean..

http://s130.photobucket.com/albums/p257 ... F_0019.flv

My first guess is crank, but you''ll need to strip it to check. Got to be a rotating part of some kind.

It seems to not be as bad when say you ride it for 25mins and then stop and idle.. seems to be worse when started from cold. Did 35 miles today and it goes great. Think maybe now weather is getting crap I might take engine out and send it to Stan Stephens for a make over.

Knocking when cold does seem to say bearings to me?

I gotta agree with the-elf on this one, it does sound like crank/big end bearing to me.
Whatever it is, I would not recommend riding it till it's been pulled down and fixed, as you'll only do more damage if it is.

Good luck, Scott.

PS. your not the only one chaseing a mystery noise atm. I have a horrible metalic grinding noise in my Tandem Twin along with oil that looks like metalic paint. Ripping the engine apart today to find the problem, and will hopefully be able to use bits from a spare parts engine to sort it out [-o<

hi mate,

sounds like big end get it sorted
my cr250 was knocking for weeks, kept riding it thought it was piston slap so i was due to change soon. had one last go engine stopped. Yes did need new piston kit aswell as a full crank rebuild and relined total bill £450 Happy Daze
get it looked at cr has 1 cylinder you have 2 double trouble....

Listen to you vid and it sounds big end or main bearing to me. Don't run it, strip and check it ASAP.

just stripped my trainee's bike(aprilia rs125)and the mains were so shot the magneto had worn through the pickup till it konked out....twit...and ive got to teach him how to work on 10 grand+ bikes.......

we all start somewhere....

but he just got lucky..if a rod goes its gonna cost ya loads if you dont nip it in the bud...small pieces of metal scraping up and down the bore is not nice.....

hes lucky its an rs cos all the bearings,gaskets,seals and piston are easy to get and cost 100 quid(labor will be lots of tea)...work out the price for a kr1s......

mines making a similar noise aswell,plus it seems to stall when last bit a choke is taken off and even has a thumpy noise before it cuts out,and when its tickin over and you rev it its struggling then whack straight round to 5 thou,does it sound like it needs some work or am i just paranoid? apart from that its greeaat! get it to someone who knows,get the work done and then thrash the thing for all its worth,thats my plan anyway just want an expert apinion first dunt i elf,red d 777 anyone who knows really me old muckers?

I was up near Barnsley today so I could have dropped by and had a listen. If it sounds simular to the vid, then I guess you're heading for a rebuild. Do it now before you do too much damage.

Do a top end rebuild at the same time. If your unsure how to do strip and rebuild it, then just ask, It's not a hard job to do. BDK are good value for rebuilding a crank with all new bearings and seals. Trouble arises if its been running with a knacked bearing and wears the crank. If that happens you'll need to source another knacked crank for the spare parts as they are NLA.

garye345 wrote: mines making a similar noise aswell,plus it seems to stall when last bit a choke is taken off and even has a thumpy noise before it cuts out,and when its tickin over and you rev it its struggling then whack straight round to 5 thou,does it sound like it needs some work or am i just paranoid? apart from that its greeaat! get it to someone who knows,get the work done and then thrash the thing for all its worth,thats my plan anyway just want an expert apinion first dunt i elf,red d 777 anyone who knows really me old muckers?

sounds like over fueling to me check your float hights but when in doubt.....crank re-build is around 250 quid,but a pair of base gaskets(i bought two from foul ups...sorry fowlers of bristol last month)and a litre of coolant is around 25 quid....not much for peace of mind...