Triumphrat

Nickwiz

Ok quick question. Before I go ranting at the dealer.

Took my 955i in for valve clearances the other week. It was running fine when it went in. The dealer told me every valve had closed up! and needed re shimming. As the bikes only done 14000 miles this was a suprise! But I stumped the readies up and let them do it anyhow as i had no choice realy.

So I get the bike back and its now got a flat spot a mile wide between 4000 and 5000rpm. So I take it back to the dealer and they re load the tune. Not sure why they had to mess with it to check valve clearances anyhow? Pick it up and it feels better.

So today I run it up the motorway to Stafford for the classic bike show and at about 4000rpm if you crack the throttle open aggressively it just over fuels and the engine won't accelerate. Puffs of black smoke and popping out the exhaust with a feeling like you've hit a rev limiter until you back off then accelerate slitly more gently/smoothly and she seems fine.

When I got it back the dealer said that it would feel different until the ECU had set itself or something like that. Now I freely admit I'm a luddite I don't understand all this Efi electrickery. So is this normal? Am I just being too heavy with the throttle? or is there something wrong with it that I do need to go back and rant about! There's no engine warning lights and nothing else seems amiss. I don't recall it being this bad before but I'm now thinking maybe its my riding technique. Too aggressive with the throttle? It only happens when I crack the throttle open to accelerate hard.

Ok over to you guys? Realy this luddite could do with a hand here.

Nickwiz

bump

Po-Lock-N-Load

If its got an O2 sensor and runs in closed loop, that could be an issue with it taking time to "relearn" the fine tune. Though WOT on most EFI systems is purely open loop off the fuel map itself.

I could see a surging/flat spot under part throttle due to the computer learning, but not WOT.

I'd say either the tune is off, the TPS is misadjusted, or the fuel pressure is way too high.

do you have an aftermarket can?

Nickwiz

Yes i have a carbon can company silencer. It is baffled though not open. What is WOT? I'm a luddite remember.

flyinloww

(W)ide (O)pen (T)hrottle

Nickwiz

ok thanks.

So what do you reckon then? Baffled race can could that be it? The dealer has loaded the standard map?

Oh I'm begining to love the simplicity of my 1200s carbs!

Po-Lock-N-Load

If you have an aftermarket can, and had a custom map loaded, then the dealer eprogrammed it, they most likely loaded a stock map, and then reloaded a different stock map the second time.

That would be my first place to look, then I'd look at the throttlebody sync, then sensors (TPS, crank trigger, airbox pressure, etc.) then coils, fuel pressure, etc.

electricblue92

Check spark plug wires; be sure everything is tight. I had that kind of problem before at WOT.

Nickwiz

Thanks for the advice guys.

Thing is the 955i has now left the building. (a garage somewhere in Birmingham!)

I realised I loved my 1200 more and kept that. But I needed some simplicity in life. Something I can understand so I bought a nice blue Thruxton bonnie.

I'll still be here tho. As I've a fair bit of knowledge on the old 1200s I'm happy to share.