slight misfire just off idle

[toucan]

i got my bike back from the shop after they fixed it after i crashed it. they also done the 50k km service.
it was idling low, about 900rpm and seemed to misfire when i opened the throttle slightly. i checked the tps it was .59V and have adjusted it to .56V.
nothing changed.
i then started fiddling with the air screws, they were at 1.75 turns out. i went in 0.5 turns and out 0.5 turns. nothing changed.
now i have screwed them out 3 turns (seems a lot to me) and its idling at 1000rpm (maybe a touch more). its still missing just off idle.
i still have not tried to synch the throttle bodies. i have a decent vacuum guage and know how to use it. but i have tried to get the butterflies to close by ear. they both seem to click shut at the same time. they were slightly off. the misfire is still there.
my question: could it be plugs? they weren't changed at the service.
could it be plug caps/coils? i would have thought they would be missing at all revs and throttle openings.
could it be the hall sensors? again i would assume the problem would be more pronounced at high revs.
could it be timing? i haven't checked that yet.
the bike is a twinspark 1150 adventure.

 

[John Armstrong]

Plug caps seem to be a favorite at the moment as they're more than just a wire covered in rubber. Other people have had them failing.

Were the plugs changed as part of the 50k service?

 

[toucan]

the plugs weren't changed.
i was also thinking about the plug caps. they have the coil in the plug and if my get off cracked it then it could be "leaking". but wouldn't that happen at all revs?

 

[cookie]

IIRC TPS voltage should be .340 to .390 too lazy to look it up

over .4 & it doesn't set properly

 

[allan]

I have the same problem, the bike is idling at about 800rpm and there is a slight cough from the engine if I open the throttle too quick.

I recently did a service where I change all filters oils and plugs as will as setting the tappets but none on the above solved the problem so I am still looking for an answer.

allan

 

[littleredrooster]

560mv is waaayyy too high for the TPS. It needs to be 375 - 390 for best performance. Reset it and then pull fuse 5 to reset the Motronic. Turn ignition on, open throttle fully 2 or 3 times before starting to calibrate the TPS.

 

[allan]

ok have to ask because Im not much of a machanic. what is TPS ?

 

[Mouse]

Throttle position sensor - it's a potentiometer on the side of one of the throttle bodies (the black box) that tells the engine management system how far open the throttle is.

 

[allan]

thanks, sorry for my ignorance.

as I said earlyer Im having the same problem so will check this tonight.

allan

 

[pomm001]

I would do a search on twin sparks , there seems to have been plenty of threads with misfires due to the coils packing up, quite expensive i believe.
You have no option now but to have the throttle bodies checked and sync'd after playing with the by pass screws, i suggest you do this before making any further adjustments, its very tempting, but dont play with too many things at the same time it will get you in big trouble real quick, that inclides the TPS settings
I wonder how I know that !

 

[toucan]

er, my mistake. i meant .36V not .56V