No Power

[Bertie_Mollie]

Hi All,

I rode the new project bike today for the first time. I knew it had a running problem but this is the first time I have tried it.

Bike seems to run normally low down but has no power from about 5500 up. It will rev more and doesn't hit a brick wall it just doesn't get much higher than about 7500 under load. The powervalves open OK when you rev the bike stationary and there is no misfiring when riding.

Before I tried it I fitted another coil and some new plugs with no improvement.

It does also smoke a lot but maybe this will clear OK when the running problem is sorted.

A reciept did come with the bike for a recent new stator but that doesn't necessarilly rule that out.

Any Ideas?

Cheers

[Garry]

you've probably checked - but are the powervalves connected correctly?

[Charles]

Hi Andrew,

The powervalves open OK when you rev the bike stationary

But are they fitted the right way? Are the linkages fitted correctly?

Any Ideas?

Have you inspected/cleaned the carbs?

cheers,
Charles

[Cliff]

As Garry says. Maybe valves.
Are the valves back to front, fitted 180 degree's reverse?

[Cliff]

Beat me to it Charles .

[Bertie_Mollie]

Just been down the shed for a look with a torch. Doesn't look like there is an obvious problem (except the timing could do with a tweak) but it isn't easy to see the flats. The linkage looks as if it is fitted correctly and opening and closing. Will need to get the tank off to get a better look and make sure the valves are the right way around i.e. flats in the right places .

[Bertie_Mollie]

Oh, and carbs not cleaned yet .

[Bertie_Mollie]

Linkages and powervalve timing look OK. Should be spot on with a bit of cable adjustment.

The carbs although very clean only have 120 mains fitted so will order up some 135's. Pilots are #40 which is OK.

Which is the "main air jet"? I can't see it referenced in the exploded view of in the fuel system section. Might as well check it whilst the bike is in bits.

Cheers

[Bertie_Mollie]

Just tried 135 mains, set the float heights and needle position but it didn't fix the problem.

Gonna try another CDI but I got a feeling Elf could have been right about the stator breaking down.

[the-elf]

I would try the stator and if thats not it then the pick up coil next to the flywheel.

[Bertie_Mollie]

I would try the stator and if thats not it then the pick up coil next to the flywheel.

Had a spare pick up coil so tried that first. No improvement .

I'll have to try get hold of a stator and try that.

[Bertie_Mollie]

OK, tried a few things since the last post with no success including stator, carb swap.

But in messing last night I decided to remove the air filter. In doing this I left the airbox lid off. When I tried it now it pulls cleaner and will rev. I wouldn't say it felt right but it was a BIG improvement.

I put the airbox lid back on (bit noisy otherwise) without the airfilter element and it was pretty much back to how it was. Seems like it wants more air or too much fuel?

I have 135 mains fitted at the moment but it did have 120's in when I got it.

Should I try the 120's again with the lid on? Although it does seem a bit small. Maybe I fixed the problem and created a new one with the bigger jets?

Unfortunately I don't know any history about this engine apart from was told it had new pistons.

Any thoughts where to go from here?

Sounds like this should probably now be in the engine section .

[Charles]

Should I try the 120's again with the lid on? Although it does seem a bit small.

I would, just for comparison.

cheers,
Charles

[the-elf]

Something deffinatly isn't right. 120 is very lean for a KR. Are the carbs standard? and what condition are the reeds in?

[Bertie_Mollie]

Carbs look standard to me. This is the second set I have tried. I haven't checked the reed condition yet. How would the reeds be the problem?