1989 GS100 PD vacuum screw

Captain Black

Well-known member
UKGSer Subscriber
Joined
Jun 24, 2008
Messages
40,259
Reaction score
4,637
Location
manchester
So the bike runs sweet but the idle is a little low at 900 RPM when warm, I wanted to adjust the idle via the air/ mixture screw but thought I'd stick the carbtune pro on first to see how balanced it was actually running.

Turns out the right vacuum closure screw is a little delicate and my fear is the head will bugger up if I use a screw driver so I though mole grips might be a better option to remove it.

My head says get a couple of spare screws before attempting removal just incase, but I can't seem to find any online.

Anyone know who stocks them for the 40 mm Bing ? It's the carb with the vac screw underneath next to the air/ mixture screw.


Edit ; maybe I could use the rubber caps like on the GS 1150 if still available. ?
 
It is only a blanking plug as you know....just simply loosen with a pair of pliers ( the screw head is wider than the carb body it is screwed into ) and cut saw a flat blade screwdriver mount into the screw head. Jobs a good 'un :thumb2
 
Motorworks, Moto- Bin,s boxxerparts and Chris Shaw stainless sell them (all in stainless).

If they are a little chewed then defo swap them. FWIW I would try a screwdriver first, whatever other non destructive method you can think of next (might help to remove the carb or spin it over at least), then moles dead last - moles first will almost certainly trash them and remove all possibility of removing them normally.
 
It is only a blanking plug as you know....just simply loosen with a pair of pliers ( the screw head is wider than the carb body it is screwed into ) and cut saw a flat blade screwdriver mount into the screw head. Jobs a good 'un :thumb2

They don't even look like a carb screw do they ...I'll have a go with pliers and try and save the head as you suggest . Got a feeling this minor rising of the idle will turn into an epic ! :blast
 
Motorworks, Moto- Bin,s boxxerparts and Chris Shaw stainless sell them (all in stainless).

If they are a little chewed then defo swap them. FWIW I would try a screwdriver first, whatever other non destructive method you can think of next (might help to remove the carb or spin it over at least), then moles dead last - moles first will almost certainly trash them and remove all possibility of removing them normally.


Ok understood , couldn't see them on motor works / motobins , I'll ring them next week. I think rather than ripping the head with the screw driver ( one is mashed pretty bad ) Maybe grips and stick a new one in . :D

Ta for the tips
 
The rubber seal off a brake bleed nipple will do at a pinch, or a bit of vent hose with a short bolt in the open end.
 
I bought them from BMW about three weeks ago (the blanking screws that is).
 
Don't like these shitty little screws do I've found a bit of clear pipe rammed a nice stainless bolt up two pieces and stuck them on.

They look quite nice under the carbs. :D
 
Save you lying on your back on a cold slab trying to get the little buggers in with the screwdriver wobbling in your arthritic hands too.
 
Years ago we used to link the vacuum take off points on Laverdas to help primary carb balancing. It was also the thing to do on 1100 GS for a while to help with surging on the earlier (big valve) 1100. There's no reason why you couldn't do it with airheads.
 
Tried it as an experiment once , thought it made the bike run a little better but it seemed to affect starting more - one cylinder cylinder will always fire first, and then the second seemed reluctant to fire for a second or two.

Other problem was the Nazi party, or BMW owners club as they titled themselves, would pull them off and tie them in knots if they came on the bike unattended.
Wasn't all bad, at least it stopped them pulling the leads of the lower plugs and stuffing them up and over the exhaust pipes or unscrewing the dip stick, or ----------------.
Only thing I ever did to upset them was to blast past them around 60 km faster any time I came across one of their runs, they seemed to think that 80 km/hr was as fast as an airhead would go.
And I think my bike sounded better than theirs too!
 
Tried it as an experiment once , thought it made the bike run a little better but it seemed to affect starting more - one cylinder cylinder will always fire first, and then the second seemed reluctant to fire for a second or two.

Other problem was the Nazi party, or BMW owners club as they titled themselves, would pull them off and tie them in knots if they came on the bike unattended.
Wasn't all bad, at least it stopped them pulling the leads of the lower plugs and stuffing them up and over the exhaust pipes or unscrewing the dip stick, or ----------------.
Only thing I ever did to upset them was to blast past them around 60 km faster any time I came across one of their runs, they seemed to think that 80 km/hr was as fast as an airhead would go.
And I think my bike sounded better than theirs too!

Was the owners club really that bad ! :eek :eek

My PD is lovely at 6K RPM in top... Does em good I reckon. :cool:
 
You just dont mess with the BMW OC.

They will bore you to death, fact.

Can't say I've had any dealings , I much prefer the dickheads on here, I feel at home in this place. :D

I was once stalked at a car show by a chap from the Porsche owners club. He insisted with an old aircooled car I owe it to the car to join ... Eah ???:rolleyes:

Loonies ...:D
 
Can't say I've had any dealings , I much prefer the dickheads on here, I feel at home in this place. :D

I was once stalked at a car show by a chap from the Porsche owners club. He insisted with an old aircooled car I owe it to the car to join ... Eah ???:rolleyes:

Loonies ...:D
Bloke I used to ride with was an ex Goldwing rider. Told me that someone from the owners club once asked him why he didn't join. Because it's full of people like you, he replied.

Sent from my Nexus 10 using Tapatalk
 
I dont think the BMW owners are anything different to most clubs.
You are either a club person or you are not , I simply have little in common with the guys who only ride in club runs.
Just too many ego's, control freaks, big mouths, back stabbers, etc, etc - some of us get as much of them as we need at work without a second dose at the weekend!
 


Back
Top Bottom