Carb options '88 R100GS

[Shep]

The worst bit on the bike now is the carbs

Runs OK once moving but its still fekking about starting from cold and a hesitation on the initial throttle openings.

I'm not looking forward to any more serious downtime in running the bike, so I'm looking at options.

One option would be to get another set of carbs from somewhere then send the originals to Steve Scrimingeor for an overhaul

Another would be to get a set of slide carbs from somewhere perhaps as a kit to fit the R100 so I don't need to fek about too much with cables and jetting etc I'm not sure if any are available?

What else is an option? Buy a bigger ultrasonic cleaner and do it myself, after all it's not rocket science, big ultrasonic cleaners are quite expensive though

Shep

 

[Rob Farmer]

Do it yourself.

Carbcleaner, WD40 with the smart tube and a propane gas filler to blow everything out afterwards.

Checkout the cork gasket to see if it's gone oval. If you get an airleak round the gasket the fuel isn't drawn up into the choke system, if this happens putting the choke on will make it harder to start than not using the choke at all -

 

[brassmonkey001]

Did you not overhaul them while the bike was in bits?
It's easy enough to do yourself.

 

[Shep]

Did you not overhaul them while the bike was in bits?
It's easy enough to do yourself.

MMMmmmm I had left it to somebody else, but when they started to play up I stripped them and it was obvious fek all had been done beyond changing a set of diaphrams. Lots of shite around the mainjets and tatty o'rings. so i did what I could without parts.

I've ordered a couple of kits and I'll have a proper go later in the week.

It runs sweet, once on the move, it's just when the airflow drops off things start to go awry.

shep

 

[Rob Farmer]

Thats the trouble with other folk doing things on your bike. They do silly things like screwdriver the paint on your freshly painted frame

 

[Shep]

Thats the trouble with other folk doing things on your bike. They do silly things like screwdriver the paint on your freshly painted frame

I've highlighted that area and called it your signature

The bike's worth loads more now it has your autograph

 

[fayeslane]

Has anyone tried a set of Mikunis or Keihin flat side carbs on their airhead? Interested to know what difference they make - good or bad.

 

[Kenny]

Flat sides are better for power....

CV carbs better for torque

 

[Roger Chatterton]

Got Mikunis on my 100GS PD, and they seem great, but not been able to do direct comparison with Bings, as bike was bought with them already fitted ( conversion done by Andrew Sexton). Twin plugged, Seibenrock pistons and barrels, Mikunis, Y piece, and silly recycling thingies removed from the airbox etc.

So, to me, it all runs a treat -smooth, no flat spots, pretty nippy, starts well, and maybe just a tad more thirsty than the Bings.
Oh, and carbs adjusted by Rob Farmer at the Gents Wee Kend helped enormously - now ticks over much better -thanks Rob !!

 

[stuart jenkins]

Hi Roger,
"and silly recycling thingies removed from the airbox etc."
Do you mean the crankcase breather that splits and then vents into the airbox-to-carb tubes?
is it blanked off before the breather gets to the airbox? or has he extended the pipe to that little outlet at the back/bottom of the airbox? when i removed mine i found oil seemed to be getting sucked into the airbox and oiling up the spark plugs more so put it back in. Has anyone else removed them with success?
I seem to be using the word 'airbox' alot, and aslo back/bottom so will sign off.
Cheers
Stuart

 

[Roger Chatterton]

Hi Roger,
"and silly recycling thingies removed from the airbox etc."
Do you mean the crankcase breather that splits and then vents into the airbox-to-carb tubes?
is it blanked off before the breather gets to the airbox? or has he extended the pipe to that little outlet at the back/bottom of the airbox?
Cheers
Stuart

Hi Stuart,
no, it's the pipes that lead off to the airbox, and they recycle some of the expelled mixture .... see pic below....an early attempt to clean up the emmissions or something. Anyhow -gone from my bike, and can't say I miss 'em at all.

 

[England-Kev]

I have a spare set here you can use while you rebuild yours

 

[Shep]

I have a spare set here you can use while you rebuild yours

Cheesr Kev

I've just this minute finished cleaning them and fitting new kits i'm going for a ride now if i have problems again i'll be in touch, cheers

Shep

 

[Redboots]

Do you mean the crankcase breather that splits and then vents into the airbox-to-carb tubes?

I did mine a while ago and vented it to atmosphere. You can take a look when you get here

John

 

[England-Kev]

Cheesr Kev

I've just this minute finished cleaning them and fitting new kits i'm going for a ride now if i have problems again i'll be in touch, cheers

Shep

So how is it now?

 

[Shep]

So how is it now?

MMMMmmmmmmm, it HAS improved, the 'choke' was totally crammed with shite blocking the tiny hole in the plate with the four indents so the cold starting has improved, there is still a slight hesitation at low revs on initial opening of the throttle, the air mixture screws appear quite worn at the tips so i may try and get some replacements. Along with needles and needle jets they must be a little worn at 65,000mls+

Other than that I may try a new set of plugs, i've noticed in the past that when old unleaded fuel is used it sometimes knacks the plugs giving similar symptoms so I may swap the plugs out and give it another go, it is a cheap option that might work.

The bike runs quite strong though and is faultless once moving, the extra power from the refreshed engine is causing a few interesting handling traits the worst of which is it shaking it's head when accellerating at speed on rough roads (80+) I think it's a steering head thing, maybe a little tight on the bearings perhaps, or could be even the fork oil's knacked as I didn't change that over the winter.

It's certainly keeping things interesting though

Shep