Appologies to those who have already seen this on the Yahoo BEC list but.....

...I finally plucked up the courage to fill the Kwak with oil and try and
start it on Sunday and hey presto - it started up almost straight away.
However it didn't sound too healthy (especially at idle) and I soon
noticed that cylinder number 2 exhaust header was not getting any
where near as hot as the other 3. It is getting fairly hot but if I
spit on the other 3 the spit bounces off it as it boils on impact
where as number 2 is more like a pathetic sizzle. I pulled the plug
out and it IS sparking. I also tried swapping plugs, coils etc but it
is always number 2 that seems to be struggling.

It is also getting
fuel as when I took the plug out to test the spark I forgot to cover
the hole and got sprayed with fuel.

I therefore think it is running on 'three and a bit' cylinders but having said that if I unplug the lead to number 2 coil then the engine sounds no different suggesting number 2 cylinder is doing bugger all!!!

I am trying to source a small
enough fitting to do a compression test (10mm) but in the meantime I wondered
if you guys could offer any suggestions? - Carb problem?

Thanks

Marc

Definitely something wrong if it's getting that much fuel.

I made an adaptor for the compression tester using an old plug - smack the ceramic off (hold plug in vice, cover plug with a cloth to avoid shards in the eye) witha hammer and then chisel the remainder out, then braze/weld a suitable adaptor or tube in. Easy.

I had a similar problem last year, but only after it had been going on full throtle. It was a carb problem, which was not solved by just replacing the float valve. I ended up sending the carbs to TTS for dynajetting and got them to sort them out, so I dont know what the true cause of the problem was, but replacing the float valve must be one of your firt jobs, and ensure that everthing is spotless.

Ive got a spare float valve if you want to try it, as I found they are not the cheapest thing you will buy.

HTH Gordon

cant you swap an carb from an good cyl to number 2?

if it then gets hot and the problem is the other you know wy..


Tks

quote:

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Originally posted by Kissy
I made an adaptor for the compression tester using an old plug - smack the ceramic off (hold plug in vice, cover plug with a cloth to avoid shards in the eye) witha hammer and then chisel the remainder out, then braze/weld a suitable adaptor or tube in. Easy.

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I am with MKNinja on this one, sounds like a faulty/dirty float valve

Thanks for the advice guys,

I have sourced a 10mm compression tester fitting and just carried out the test.
All 4 cylinders showed similar levels (about 155-165 PSI) which is within the tollerance stated in the Kwak Haynes Manual.

As far as I can see, a cylinder that has compression, a spark and fuel but not getting hot must be getting too much fuel and hence I think you's must be right about it being a carb problem but it's nice to rule out low compression first.
I'll start to investigate the carbs and keep you posted on my progress.

A difficult question to answer I realise but just how rough does a bike engne run before it has been jetted for a kit car set-up that has a different exhasut and no airbox?

Thanks

Marc

Not trying to teach you to suck eggs, but if you remove the carbs, take all 4 off as a bank (dont take the bank apart) and remove the bowls that way... Sure you know this, but others may not...

Also check the diaphragms (sp) in the carb first, as if it has a tear or is not seating properly it may not be opening the throttle on that cylinder and hence not fueling it properly...

Even though you are getting a spark on number 2, it might be quite weak or the plug could be breaking down internally. Easiest check is to swap the plug onto another cylinder and see if the problem moves to that cylinder. If not, then it sounds like a fueling problem.

I had a similar problem with my R1, it kept blowing 1 plug. This was over the winter as i was just starting the car, running it for a few minutes, a bit of revving and then turning it off before it got too hot.

I dont do that anymore, if i start it i always go for a quick blast up and down the road and it hasn't blown a plug since.