Carb OEM specs as per factory manuals

[Robyle3]

LOTS of pages here so I don’t know if it’s been posted before (did a few searches so I’m fairly confident it hasn’t lol).

GS 550 L
1983
Mikuni BSW30SS Model

Carb (2 separate carbs, twin bore)
bore size 30mm (1.2in)
id no 43510
idle r/min 1100 +/- 100r/min
fuel level 6.5mm +/- 0.5 (0.26 +/- 0.02)
float height 20.5mm +/- 1.0 (0.81 +/- 0.04)
Main jet: cyl 1 and 4 #95 cyl 2 and 3 #105
Main Air jet 1.0mm (0.04in)
jet needle SC64-1
Needle Jet P-3
Throttle valve # 120
Pilot Jet #35
By-pass 0.8/0.7/0.8/0.8mm (0.03/0.02/0.03/0.03in)
Pilot Outlet 0.7mm(0.02in)
Valve seat 2.5mm(0.10in)
Starter jet #55
Pilot Screw............. pre-set
pilot air jet # 150
throttle cable play 0.5-1.0mm(0.02-0.04in)
choke cable play 0.5-1.0mm(0.02-0.04in)

Hello mate. I got hold of a '79 850 and did the same. Did you work out the turns to get the mix initially right? And the needles? If you had any success and can remember the settings, it would be really cool if you can divulge. I'm over in the UK in Cornwall so it's probably night time over your side. Hope to get a response from you soon. All the best.

[DR3]

Lets see if this works. I've been following your search for answers on this and found specs in the GS 700 manual linked to on Cliff's site.

[ATTACH=CONFIG]61084[/ATTACH]

Rats, it's too small to blow up. Check here though.http://zeus.mtsac.edu/~cliff/storage...ice_manual.pdf

Cool, thanks Roger! I also found this:

http://gsarchive.bwringer.com/bikecl...at_height.html

Not sure why my jets are different than the specs. Could it be because the previous owner had a K&N filter in the air box? I got K&N pods and a Dynojet kit which calls for the Main Jet to be 130. Would I need to change other jets for this reason and if so what do I put if the Main Jets are 130? This is what came on the bike when I bought it:

"(in parenthesis)" = Chart/Manual specs

Main Jet: #120 (#122.5)
Main Air Jet: ? (1.7 mm)
Jet Needle: 5D10, but with the kit its a DNT604 (5C-28)
Needle Jet: Y-7 (Y-5)
Pilot Jet: #40 (#37.5)
Throttle Valve: 135 (manual says 135, but not chart... weird)
Pilot Outlet: ? (0.7 mm)
Valve Seat: ? (2.0 mm)
Starter Jet: ? (#45)
Pilot Screw: 2.5-3 turns (pre-set)
Pilot Air Jet: 155 (chart not specified, manual says pre-set, part #09493-3200 says 160)

I would like to know the ones I have "?" marked. How can I find these? Starter jet, is that the one that's built in, for the choke?

[Burque73]

Hi!

Does anyone have carburetor specs for a 1985 GS700ESF?

Thanks in advanced,
Andre

Lets see if this works. I've been following your search for answers on this and found specs in the GS 700 manual linked to on Cliff's site.

GS 700 carb specs.jpg

Rats, it's too small to blow up. Check here though.http://zeus.mtsac.edu/~cliff/storage...ice_manual.pdf

[DR3]

Hi!

Does anyone have carburetor specs for a 1985 GS700ESF?

Thanks in advanced,
Andre

[Gorminrider]

jamuso, not to be too snippy about it but why not use the "Search This Thread" box? Putting '"GS750" into it gets me all kinds of 750 stuff.

also for a shop manual that has the info and much else goto BikeCliff's Website

I have a 1977 gs750 that was my dads, I have recently did a tear down of the carbs and a did a complete rebuild, I would like to know if anyone has the factory settings for the needle valve, fuel/air, and how I need to sync the carbs. the bike has the stock airbox and exhaust.

Thanks for the link.

Light snow today....warmed up a bit from the weekend. Think -25ish vs -32.....not bad lol

[tom203]

Looking for the carb specs on a 81 gs1100 16 valve motorThanks.

Here you go.... How's the weather?http://members.dslextreme.com/users/...eight.html#A01

Looking for the carb specs on a 81 gs1100 16 valve motor
Thanks.

Air screw should about 2 full turns out.
Use the highest idle method - adjust the idle to about 1,250 rpm and adjust each air screw in half a turn then back it out as you listen to the engine for highest idle.
Then adjust the idle to 1,250 rpm and move to the next carb, repeat.

BTW, have you adjusted your valve shims lately? If the valve shims are not within spec you'll always have trouble adjusting the carbs.....
Then of course you will need to balance the carbs with a vacuum sync...
It's a continuing battle with these old machines.....

Hi, bike is running nearly fine. 105# main, 15# pilot jet, needle midt pos. ( was on 4 th. ?), Mix screw down 2 turn out, air screw up 2 turn out, float 24 mm, new O-rings, Engine Valves shims correct.
I need new needles ( worn ) 5DL36

Thanks for help and answers
greetings
Bernd

[allojohn]

Thanks for the answer.

Pilot jet is 15" original
Main now 80" original Mikuni
I newer buy aftermarked jets again ! They dont work at all.
Will go for 95" Main Mikuni.

Should the Air Screw on Top be fully closed ?

Air screw should about 2 full turns out.
Use the highest idle method - adjust the idle to about 1,250 rpm and adjust each air screw in half a turn then back it out as you listen to the engine for highest idle.
Then adjust the idle to 1,250 rpm and move to the next carb, repeat.

BTW, have you adjusted your valve shims lately? If the valve shims are not within spec you'll always have trouble adjusting the carbs.....
Then of course you will need to balance the carbs with a vacuum sync...
It's a continuing battle with these old machines.....

OK, I'll give this one crack.
What pilot jet do have in there?
I believe stock main jet is 80, so 95 with stacks sounds about right.
The fuel screw under the carb should be closer to 1 full turn out.
Air screw is close.

You might get a better response if you start a new thread.....

Thanks for the answer.

Pilot jet is 15" original
Main now 80" original Mikuni
I newer buy aftermarked jets again ! They dont work at all.
Will go for 95" Main Mikuni.

Should the Air Screw on Top be fully closed ?

[allojohn]

OK, I'll give this one crack.
What pilot jet do have in there?
I believe stock main jet is 80, so 95 with stacks sounds about right.
The fuel screw under the carb should be closer to 1 full turn out.
Air screw is close.

You might get a better response if you start a new thread.....

Hi, I have a GS 550 from 1978 with VM22SS Carbs.
4 in 1 Exhaust and open Velocity Stacks.
The bikes is very rich with 95" Main Jets. Struggling and misfire to rev higher. Black Sparks
Should i go for 80" ?
Float level 24 mm
Air Screw on top of carbs: 2` back
Mixture Screw under the carb: 2`back
Anyone an ide how to set the carbs up ?
Thanks.
GreetingsIMG_20180318_201812.jpg