bike gaining revs

hello all

just started up my 03 r1 after being parked up for 3 months, all was fine when parked up but now it seems i have a problem, started up first time but usually when started from cold she ticks over at about 1250 rpm and then autochoke slowly drops down to about 900rpm, now it seems to be gaining revs as it warms, after about 5 mins running she slowly picked up to about 3000rpm!

any ideas as to why this may be happening, i did put a large dose of fuel stabilizer in her just before storing, about double the dose, could this be the cause?

thanks in advance

had same prob with my 04 R1, if you remove the tank & look under the air box on the back of the throttle bodies there is a small cylinder with two pipes going to it. this is the problem you need to take it off from throttle bodies i think its two phillips screws,then work the plunger in & out then spray with wd40, clean off & grease the plunger, be carefull if tou have to remove pipes as they have coolant running through them. you can do it with pipes still connected. also ther is a spring from the plunger to the throttle bodies take care may go ping f**k it. forgot to mention you have to remove air box to. if you are not shaw on doing job call yamaha dealer should only cost about 1 to 1.5 hours labour.

problem seems to have solved itself with a good blast down the m1, think putting the whole bottle of stabilizer in was the problem, bike was just demanding more petrol and getting way to much additive, LESSON LEARNED, LESS IS MORE!

Just had similar symptoms with fishfaces zzr250, are you talkin abiut the cylindrical gismo with the diaphragm inside ?. I seem to have cured the problem but am not quite sure what this component is…i assume it is a vac operated valve for the carb heaters / yes/no ?..if so, why would it cause the revs to rise on an otherwise correctly functioning engine on a warm day ?

If it was plumbed into the inlet on the engine side of the butterflies and it was leaking or sticking it could be letting more air in which would make it rev up a bit.

its a hot wax plunger basicly when its cold its all the way out & pushes on the throttle linkage so revs are higher for cold starting, then once the coolant warms up wich runs through it, it melts wax & plunger is able to retract leting the engine idle as normal all yamaha,s use this system not shaw about any other manufactures but i imagine they would use similar system.

Thanks for that fast eddy,tis a different gismo to the one on the zzr but that is still very interesting…in these days of pt100’s,thermocouples,thermostatic switches etc…yamaha are using hot wax, i love it.

well siting here bored shitless no work to do I’ve just remembered the name off that gizmo now i am awake… :hehe: its a air cut off valve for the carbs.any who back 2 wot i was doing:D