2006 Gsxr 1000 Fouling #3 Plug On Dyno Run

[dawnrazor]

So my bike has been running rough as guts for the last few months, pretty much since the start of winter. I've had it in and out of the shop trying to find why it's been cutting out and backfiring. General consensus was that it's running rich, get a power commander on there and that'll sort everything out. For the record it has 24K on the clock, a yoshi pipe and DNA filter

So last Friday I had new plugs fitted and on Monday morning I dropped it into the Dyno guy to fit the PCV and get it mapped. He did several runs, and as you know a dyno run is a redline experience right, nothing namby pamby going on there. Comes back to the bike after 3 full runs and #3 cylinder has dropped out and the plug is fouled. It's not oil fouling, it's fuel fouling.

Can anyone give me any idea of what might be going on here. The garage are at a loss to explain it.

The only ideas I've had are to swap leads to see if the problem moves with the leads or swap injectors to see if the same thing happens, but that doesn't really fix the problem does it.

I've spent a fortune on the bike in the last few weeks because of this, now I'm in the for another surprise when I collect the bike from the dyno and the bike still isn't right. All along my fear has been that there is an underlying issue that hasn't been fixed and what do you know.

[ronenige]

Possibly tight valves on no3 , I know it's being wise after the event bet even dynojet say not to fit a pc or kit to a bike unless it's running fine , we have had a similar issue on a certain paramedic's bike ( flymo )at a similar mileage and it was down to a slight bit of wear in the throttle spindles giving a slight kick to the throttle position sensor , the fix is to space the tps out a couple of mm , the extra kick gives a double squirt to the cylinder in question , it would take a good bloke to find if it was this as the best way is to use a 'scope and compare inputs to injectors on a good and the faulty cylinder , it might be worth just trying the tps thing as it costs nowt

hth