St1300 idle tick over problem

[easy rider]

Is it stalling at idle only, fine when opening up the throttle?

Once its got going its fine no issues when running its just that initial start up but then after a run you can come back and go back to it after its been left for a while then it plays up again. you can here it in the tick over it sounds off and this morning it started to shake and the idle was really rough its not happy.

This weekend going to get the vac hoses checked and 5 way T might even replace map sensor and coolant sensor as i have spares on hand. So disappointed with it i bought it to replace my old 136 k miles ST1300 and this was fine at first then suddenly this started happening.
It does seem to be now the temperature has got warmer outside, I do know if there is anything in the vac hoses that when the bike heats up and cools it can effect how that melts and sits in the lines which can mean different running situations. It can't be serious as it would not run fine when warmed up and full running. Below the air box is the only place we have not checked on this bike so will see what we find.

Things to check -

Vac hoses & 5 way T
throttle body sync
check wires on throttle body
Check linkage is ok
Map & coolant sensor ( I have them so can't hurt )
Check the 4 round throttle body rubber boot seals for cracks or signs of drying out as although low milage it is still 13 years old and has been sitting around a lot over the years.
These were built to ride and some people just get them for summer only so only small milage while I ride all year so it will get run regular when it runs.

Take it from there i guess

Best wishes

Martin

 

[easy rider]

On way home now would not hold idle when stopping at traffic lights had to hold throttle open then after a short run settled and holding idle. No I am home it will probably be the same after sitting for an hour or so.

 

[MidLife]

Once its got going its fine no issues when running its just that initial start up but then after a run you can come back and go back to it after its been left for a while then it plays up again. you can here it in the tick over it sounds off and this morning it started to shake and the idle was really rough its not happy.

This weekend going to get the vac hoses checked and 5 way T might even replace map sensor and coolant sensor as i have spares on hand. So disappointed with it i bought it to replace my old 136 k miles ST1300 and this was fine at first then suddenly this started happening.
It does seem to be now the temperature has got warmer outside, I do know if there is anything in the vac hoses that when the bike heats up and cools it can effect how that melts and sits in the lines which can mean different running situations. It can't be serious as it would not run fine when warmed up and full running. Below the air box is the only place we have not checked on this bike so will see what we find.

Things to check -

Vac hoses & 5 way T
throttle body sync
check wires on throttle body
Check linkage is ok
Map & coolant sensor ( I have them so can't hurt )
Check the 4 round throttle body rubber boot seals for cracks or signs of drying out as although low milage it is still 13 years old and has been sitting around a lot over the years.
These were built to ride and some people just get them for summer only so only small milage while I ride all year so it will get run regular when it runs.

Take it from there i guess

Best wishes

Martin

Rough idle can also come from the mixture being too rich at idle, which could possibly come from a pressure regulator not sensing vacuum and not opening up to bypass more fuel while idling.....like what a clogged vac hose or T might cause.....

 

[easy rider]

Rough idle can also come from the mixture being too rich at idle, which could possibly come from a pressure regulator not sensing vacuum and not opening up to bypass more fuel while idling.....like what a clogged vac hose or T might cause.....

I hope its something simple like a clogged T or vac hoses, idle is very jumpy and stutters when you go back to it after its been run then left to sit, I managed to lift the tank tonight and removed the fuel tank breather hose and blew air through it to check its clear. So the weekend will be the point we know as going under the air box is the only place we have not been since i bought the bike. I have a new pressure regulator on my old St1300 as well as new idle air control valve , coolant and map sensor are also available as i over hauled my old ST1300. So will work my way through all that after checking vac hoses & T plus a throttle body sync. Will keep you all updated. Started up my old St1300 tonight and she runs perfectly bit smokey at first and i had a panic as it had FI light for IAT sensor 9 flashes which was because i forgot to plug it back in after swapping it from my new ST1300 so its all good.
Must try and get that u joint replaced on it as even with 136k on the clock she still sounds great, shame about my new ST1300 hopefully get some answers this weekend fingers crossed.

 

[easy rider]

Work has begun the bike seems to be missing at low revs rough idle in warmer weather and when bike is warm after riding left to sit starts with rough idle and stall starts missing at low revs. Doing vac lines 5 way T checking throttle body boots plus stater valve sync. Inspect area under throttle body.
Take it from there and report back to you all
Fingers crossed

 

[easy rider]

No blockage in 5 way T replaced hoses with new plus replaced the T carried out throttle body sync swapped out Map sensor.
See what happens I guess. We did notice one of the valves was more dirty with carbon the other three were clean so possibly a faulty injector. So swapped injector over to see if the issue moves to the other valve when it’s next in. Keep you updated everyone

 

[MidLife]

No blockage in 5 way T replaced hoses with new plus replaced the T carried out throttle body sync swapped out Map sensor.
See what happens I guess. We did notice one of the valves was more dirty with carbon the other three were clean so possibly a faulty injector. So swapped injector over to see if the issue moves to the other valve when it’s next in. Keep you updated everyone

Did you try to idle with the vacuum line to the regulator disconnected (and plugged)?

That should lean out your idle mixture and maybe help diagnosing a mixture/injector issue.

 

[easy rider]

Did you try to idle with the vacuum line to the regulator disconnected (and plugged)?

That should lean out your idle mixture and maybe help diagnosing a mixture/injector issue.

Will pull injector off my old ST1300 if needed
Along with the pressure regulator.
It was not me doing it so I doubt they checked that. The weather is colder today so good chance it’s starting fine because of that,
Not getting too excited just yet, we have the parts just a case of swapping out as we work through each issue I guess.