Hi Guys, Could do with your advise on setting the idle please. My bike is used for racing only and I’ve removed most of the switch gear including the choke / fast idle and associated cable. The tick over sits at about 1000 + / - 50 rpm and often stalls. If I keep a tiny bit of throttle on he’s fine. How do I increase the idle speed, I understand it should be about 1200 rpm which would work nicely. Thanks in advance.
There an air bypass screw on each throttle body. Should be adjusted equally. I’ve set mine to idle at about 1400 rpm. A bit higher would be better for my liking on track. But makes dropping in to 1st when setting off rather nasty. Also I run a bespoke Ecu. So to improve throttle pick up out of slow corners. I have closed the bypass screws and cracked open the throttle butterfly’s. I’m not saying this what you should do. But it helped mine out of hairpins.
Not knowing where your bike is at The throttle bodies need to be balanced the idle speed set and the use of the air bleed to Balance it out at idle along with a tps reset .. any one of which could be the problem depending on what’s occurred with your bikes history.., you could also use a pair of vacuum gauges to confirm idle balance
TPS reset in the first instance, imho. Costs 20 quid or so for the lead and gizmo to do it. The software is free, so do it at least once a year for no further outlay. People often say how much better their bike feels after a service. It's the TPS reset doing that. It couldn't be simpler to do, the software and gizmo do it for you.
Trouble is if the tb's have been altered and wrong, just resetting the tps in the first instance will not cure the problem! you need to confirm the tb's are balanced and the idle speed correct and then reset the tps, as you are resetting it to the throttle which is in the correct position. TPS is just matching the right amount of fuel as per the fuel map relative to the revs and throttle opening for the front cylinder, ( and both if they are balanced correctly) If the front is open 10 degrees and the rear 5 degrees and you reset the tps you are giving it 10 degrees of air and idle speed fuel....
Indeed but unless you have reason to suspect the throttle bodies have been messed with, there's a fair bit of potential for making things worse. Resetting the TPS should be done regularly anyway, so is well worth a try to see if it cures the problem as it is so simple to do. Imho.
You cam alter the throttle stop position screw on the tb. Its covered in yellow tamper proof paint. But have all the checks done above.
Well that’s sorted then. Thanks guys. The main difference was after adjusting the air bleed screws on the throttle bodies and equally. Access is very good, I thought I would have to dismantle the air box but having the removable rubber lugs on the left hand side was a god send. Turning out the bleeds screws made the difference, just half a turn (anti clockwise) equally on each but, I could hear the difference when I did the rear / vertical TB. Idle speed hasn’t gone up much if at all but its much more stable and the bike burbles along nicely on its own without stalling. Thanks again guys.
