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not firing on one cyl

Posted: Fri May 13, 2011 5:45 pm
by callyboy
Watcha, quick question before i get me spanners out tomoz. Started the Impulse up today and it felt really lumpy. sussed out it wasnt running on number one cylinder. Apart from checking the coil connections and plug/ht leads is it likely to be anything else ?

Cheers (sits back and waits for the abuse)

Pete

Re: not firing on one cyl

Posted: Fri May 13, 2011 6:06 pm
by Pop-Kat
plug ?, float height ?, crap in the needle valve ?, blocked pilot jet ?..
Start with swapping a plug as thats easiest.

Re: not firing on one cyl

Posted: Fri May 13, 2011 6:23 pm
by Katgeezer
Yup,plug swap to start with then go from there.
If problem persists on same cylinder then suspect carb,if it moves with the plug then obviously it's the plug. (I know which one I'd prefer it to be given the problems these carbs give)

Re: not firing on one cyl

Posted: Fri May 13, 2011 7:36 pm
by callyboy
Cheers guys.

Because these things bug the hell out of me i couldnt resist a quick fiddle - oo errr !

Took the plug out and cranked it over to see what the spark was like. It was pretty weak and seemed to be sparking more on the side than from the electrode. Swapped the plug with one of the old ones and she fired up fine :)

Now, all the plugs were new. Why would this one crap out so soon ? will have a look at it tomoz when its a bit lighter. Maybe it got some carbon on it or something.

Cheers

Pete

Re: not firing on one cyl

Posted: Fri May 13, 2011 8:28 pm
by fossie
if the spark seems to be reversed check the LT wires are the correct way round, if it's no 1 xarb , was it on side stand?

Re: not firing on one cyl

Posted: Fri May 13, 2011 8:32 pm
by callyboy
Watcha Fossie, yeah, was on side stand (dont have a centre stand fitted).

Not sure what you mean about the spark being reversed though :(

Pete

Re: not firing on one cyl

Posted: Sat May 14, 2011 11:14 am
by fossie
if you have the orange /white wire and the yellow black on the opposite terminals the voltage goes round the coil the wrong way sending spark from out side in !
Discuss!

Re: not firing on one cyl

Posted: Sat May 14, 2011 1:10 pm
by callyboy
Well it seems ok on the diff plug, so i rekon i have the leads the right way round :)

Still not sure what you getting at with the side stand thing though. :? :?

Pete

Re: not firing on one cyl

Posted: Sat May 14, 2011 6:43 pm
by Katgeezer
There's usually a side-stand switch Pete and on the kat400's they can play up and cut the ignition.

Re: not firing on one cyl

Posted: Sat May 14, 2011 7:17 pm
by callyboy
Watcha Chris,

yeah. i have taken my switch off(coz i can) still have a light on for it though. will take the bulb out i think.

Wouldnt effect just one cylinder though. would it ?

I thought maybe fossie was thinking more about dirty fuel ending up on that side if it was on a side stand. I dunno though :(



Cheers


Pete