And i think we have a culprit. after changing over my airbox to an early version Evo unit, i had okay running if somewhat woolly & down on power for a while with a rene #2 chip & Rene pipes.
The Rene airbox was out of comission for a while as the previous owner neglected to mention that the filter should have had a wire mesh on the inside to stop the top of the filter being sucked down into the velocity stacks causing a large hole & burnt filter goo everywhere -I have this posted somewhere with amusing photos.
Got the time to switch back to my stock bodywork(silver), soldered some led signals which had been broken in a prang back together & attempted to replace a clutch slave seal, but failed in this, no biggie I'm sure someone has been through this before!
Back to the airbox change & general rece of the intake area, I hadn't changed anything after fitting the evo unit & the rene airbox had produced clean, smooth results previously.
There was some slight fraying around the hose going into the evo pressure reg, but I cut the affected piece off & taped around the hose at the end to stop wear from the baseplate wearing against the top. I will make another mod of the plate to accomodate this properly when I next pull it apart. all the other airbox hoses were routed correctly & looked fine.
There is no obvious physical cause as many others have experienced, like missing lambda sendor plugs or leaking pipework around clamps & such, so I can only guess that the tech who recently serviced the valve train messed around with one of the following or it just needs to be reset after the switch back:-
- Evo fuel pressure - 43 PSI (using guage & engine off - 1st fuel prime ~3seconds), maybe 1 or 2 PSI+ as this bike has an open system which should probably be a little more fuelhappy for optimum
- TPS = 0 when diag wires connected - adjust if needed
- Throttle synch/bleed screw setting - start 2 turns out for both, bring in rear to ~1 1/4 turns out (or centre line on guage), match front off this to centre line, should be another 1/4-1/2 turn out again as normal.
- Wires under pressure reg are not grounding
i guess every filter will have it's own exact characteristic, i did'nt think the outcome would be so dramatic that I would get the dreaded ka-boom around 4, 500 rpm on the throttle, that's right on, not off, you can almost feel the fuel build-up, when it hits 6000+ it tears right off though!!!!
i want to get this right before doing anything like putting a powercommander on it, best results are gotten from a good baseline i would have thought?
Here's some pics of my cack-handedness(had too redrain the slave cyclinder after forgetting to put back on the half-moon shaped spacer under it $%^&£"), a man too mean to buy 2 new copper o-rings & possibly the dirtiest rag ever posted.
Two questions I ask thee: -
Anything i might have missed for sorting the backfire?
How do you break apart the slave to replace the seal, I even put it in a bench vice & gave it a few digs with a plastic mallet, not a budge!