Fast idle question

[Osprey]

The fast idle lever on my 2002 1150gs seems a little hit and miss. Generally, (and i think i understand this correctly) when starting from cold, I should hold the lever fully up and the once fired up, should release it to it's centre position which should stay in place until a couple of bars appear on the temp gauge. Only on a couple of occasions has the cold position caused the engine to actually idle at around 2 thousand rpm, all other times the engine speed is the same as when the centre position is selected. Does this warrant investigation or is it just another quirk?

 

[davegs]

Fast idle

All it does is speed up the engine it isent a chokeas such, just give it a bit of
throttle and it will always start waste of time messing about with the lever I never use it even in very cold starts.

 

[Johnwhit]

i start with it on it settles at about 2000 ish rpm while I put my gloves on and drive off and put it back to low about 12/ mile down the road. I find it useful if not used on cold mornings it stalls when getting to the first T-junction.
John

 

[Deleted account 250319001]

I always set the fast idle in the centre position where it sits. Start the bike, runs at around 1800rpm, gloves and helmet on and ride off. Then when on two bars i knock it off.
Thats what the Manuel says and that's what I do. Simple
BMW wouldn't add this to machine if it didn't require it
If your idle is not doing this, then take a look.

 

[Fanum]

All the fast idle lever does is move the cam in the cable splitter box in front of the air box a little, so the idle revs increase as both throttles are held open a little.

There is a little tiny ball bearing in a channel in the switch gear on the left handlebar, and a return spring in the bowden box (the little box that splits the throttle cable into two cables under the battery box area)

The little ball bearing fails quite easily and it's a bit of a pig to replace, and quite expensive (especially if you follow what the computer says you have to do and replace the whole kit with OEM parts)

It's also unnecessary.....just start bike and hold it on throttle at about 2 k revs for 30 secs and it should have warmed up enough to tick over at idle after that.

I ran for a few years with one of my daughter's hair bungy things wrapped around the fast idle lever to give it the required friction against the return spring, but once you have the bike tuned properly, you don't really need it in the UK at least.

The other option is to adjust the idle speed on both throttle bodies so it's at 1200rpm or so, maybe up to 1500rpm......it won't hurt anything but over a long period, if you sit at lights or something a lot, it will obviously use more fuel, and in the summer, you want the idle lower so it gets a chance to cool a bit more.

 

[Deleted account 250319001]

All the fast idle lever does is move the cam in the cable splitter box in front of the air box a little, so the idle revs increase as both throttles are held open a little.

There is a little tiny ball bearing in a channel in the switch gear on the left handlebar, and a return spring in the bowden box (the little box that splits the throttle cable into two cables under the battery box area)

The little ball bearing fails quite easily and it's a bit of a pig to replace, and quite expensive (especially if you follow what the computer says you have to do and replace the whole kit with OEM parts)

It's also unnecessary.....just start bike and hold it on throttle at about 2 k revs for 30 secs and it should have warmed up enough to tick over at idle after that.

I ran for a few years with one of my daughter's hair bungy things wrapped around the fast idle lever to give it the required friction against the return spring, but once you have the bike tuned properly, you don't really need it in the UK at least.

The other option is to adjust the idle speed on both throttle bodies so it's at 1200rpm or so, maybe up to 1500rpm......it won't hurt anything but over a long period, if you sit at lights or something a lot, it will obviously use more fuel, and in the summer, you want the idle lower so it gets a chance to cool a bit more.

Why bother doing all that when BMW have put a nice little lever to do it all for you
Instead of holding the throttle open, you can be putting on ya gloves, stubbing ya fag out, putting ya helmet on, giving the tosser sign to a tosser riding past etc

My Austin Champ had one too. Just pull it out and start the engine. Although this was also used to run up the engine when Transmitting.
Not a choke. A hand throttle/fast idle.

 

[Fanum]

Why bother doing all that when BMW have put a nice little lever to do it all for you

Because if you ride all year round, the little lever fails quite quickly (a couple-5 years, not weeks I mean)

Replacing it is a PITA and expensive.

That's why

I've got the Bowden box out of a GS at the moment, and we're looking at a way of making a much easier and cheaper fix.........replacing the left hand side switch gear is not an easy option

 

[Deleted account 250319001]

Because if you ride all year round, the little lever fails quite quickly (a couple-5 years, not weeks I mean)

Fair enough point. I only use mine for trips.

 

[ahutcheon]

Replacing it is a PITA.

Ain't that the truth. Wouldn't be too bad if you don't have heated grips, but who does that describe that rides year round and wears out the lever detent. Why oh why does the heated grip wiring have to run through the unbroken clamping ring by which the fast idle assembly slides over the handlebar. Cue tank removal, disconnection of wiring under the tank, pulling wiring out of (now loosened to get at the hole) bars... Reassembly is the reverse of removal. You did remember to leave something threaded through the bars to pull the wiring back with, I hope?

Next time mine starts to get a bit stiff (yes, I know), I plan to dismantle the lever assembly (merely a minor nightmare of assorted tiny hidden screws) and re-grease the bearing/spring/track in the hope of delaying total failure due to rusting.

Unless Fanum can sell me a better answer by then...

 

[giustra199]

I always set the fast idle in the centre position where it sits.

 

[MikeP]

Generally, (and i think i understand this correctly) when starting from cold, I should hold the lever fully up and the once fired up, should release it to it's centre position which should stay in place until a couple of bars appear on the temp gauge.

The rider's handbook says that the fully-yanked-back position is for very cold conditions and once the engine is running the lever should be released back to the first detent (that's why it isn't designed to remain in the fully-yanked-back position on its own). Normally, only the first position is required (where the lever will stay on its own - as long as the thing isn't fecked).

Mine stopped holding on the first detent many years ago and despite new cables and cleaning the accumulated crap out of the splitter-box recently, it still doesn't. I have one of those throttle-lock things on the bike, so all I do is open the the throttle a little before pressing the starter. As mentioned, this does exactly what the fast-idle lever does.