[Derhi04]

I have recently serviced my L1 and changed the spark plugs NGK CR9EIA-9 and the engine was running fine prior to change but now it has a flat spot and on idle the needle is jumping any ideas?:shifty

At low revs its like bogging down and then picks up as soon as the revs go up, I have got a power commander fitted

 

[BillV]

Make sure the coils are properly seated on the plugs. Off hand, it sounds like you didn't get all the hoses back where they belong.

 

[nightrain]

If everything else checks out, change all the plugs again! Unless you are able to locate a bad one by trial and error. Those Iridiums are sensitive little Fockers! If one was dropped, forget it. I've had trouble with 'em on 2 bikes already...

 

[kwaka10r]

Following on from nightrain I came across an interesting post a couple of days ago where it appears a couple of other forum members experienced problems with Iridium spark plugs.

Read post #22 which also contains a quote to an earlier post where someone experienced the same issue.

http://www.gixxer.com/forums/showthread.php?t=272785&page=2

I had a very similar issue a few days ago after really giving my 750 some juice for a few minutes. Started experiencing hesitation, poor throttle response and power. Limped the bike back home. Took it for a ride the next day and everything seemed to be fine again.

However, no one reported a jumping tacho needle so maybe it's not the same issue. Just worth noting in case someone ends up chasing their tail and doesn't consider the spark plugs.

 

[v6stanger]

Had similar issue. Chased around everything only to find the plugs that had low mileage and looked brand new were bad. Had surging idle, poor response etc.