GS 850 Carb Question

[Kiwi Canuck]

I'm helping one of my friends to rebuild a set of carbs for his 1981 GS850, and a set for one of his other "spare bikes"
He purchased a few bikes and a bunch of carbs a while back so he would have enough spares.

I have gone through all the carbs he has to identify the best ones to rebuild so he ends up with two complete rebuilt racks.

One set is numbered 45120 was already stripped down and is in very poor condition (broken float posts) so probably not the best set to rebuild, and was probably the original set off his bike and two sets are 45170's and both in OK condition but one is very gummed up with shellac.

I need some help identifying what year 2 of the sets come from.
I found the following, but could not find info on the 45120 or 45170's
1980 45110
1981 45110
1982 45160
1983 45160

I got this info from Alpha Sports site.
Any ideas?

BTW the 45170's have 115 main jets and 200 for the pilot air jets.

Thanks

[Steve]

I don't know what year the 45170s came from, but 115 mains were stock for all the 850s with BS-series carbs.

The only year that had 200 pilot air jets was '80, it also had smaller pilot fuel jets, 42.5. Suzuki quickly found that that combination was too lean, they installed #45 pilot fuel jets and 180 pilot air jets.

The only other thing to watch for when mixing years of carbs like that is the "choke" activation mechanism. Starting with the '82 models, the linkage on the carb rack was different and the upper end was a lever under the left handgrip, not a knob in the center of the steering stem. There were no changes to the carbs themselves, only to the linkage that bolted on to them.

.

[Kiwi Canuck]

I don't know what year the 45170s came from, but 115 mains were stock for all the 850s with BS-series carbs.

The only year that had 200 pilot air jets was '80, it also had smaller pilot fuel jets, 42.5. Suzuki quickly found that that combination was too lean, they installed #45 pilot fuel jets and 180 pilot air jets.

The only other thing to watch for when mixing years of carbs like that is the "choke" activation mechanism. Starting with the '82 models, the linkage on the carb rack was different and the upper end was a lever under the left handgrip, not a knob in the center of the steering stem. There were no changes to the carbs themselves, only to the linkage that bolted on to them.

.

Thanks Steve,

The 45120's had the choke linkage off carb # 2 (older style) and the 45170's have the linkage on carb #4 with the curved tube to guide the cable, so clearly a later model carb, so I will swap the linkage over to one of the 45170's that I rebuild.

All 3 sets were fitted with 200 pilot air jets and they don't look molested which is strange as the manual shows 190's for 1981 and 180's for 1983.

The pilot jet is a 42.5 on the 45170's but could not remove any from the 45120's as they are all damaged and appear seized.

Some one has 180 air jets for the GS850 on the forum, should I get those?

Edit just see you PMed him

[Steve]

Some one has 180 air jets for the GS850 on the forum, should I get those?

Edit just see you PMed him

You want them? I'll pass them on to you for the same price I paid for them.

.

[Kiwi Canuck]

You want them? I'll pass them on to you for the same price I paid for them.

.

Thanks, that would be very nice of you.

Cheers,

David

[simonw]

Thanks Steve,

The 45120's had the choke linkage off carb # 2 (older style) and the 45170's have the linkage on carb #4 with the curved tube to guide the cable, so clearly a later model carb, so I will swap the linkage over to one of the 45170's that I rebuild.

All 3 sets were fitted with 200 pilot air jets and they don't look molested which is strange as the manual shows 190's for 1981 and 180's for 1983.

The pilot jet is a 42.5 on the 45170's but could not remove any from the 45120's as they are all damaged and appear seized.

Some one has 180 air jets for the GS850 on the forum, should I get those?

Edit just see you PMed him

Out of interest how did you go with those changes ? I have the 200 - 42.5 setup and am wondering whether its worth swapping out? (the bike isnt runnng yet so I have no baseline)

[520eek]

I just started cleaning carbs today and noticed the air jet on #2 carb is different than the rest .....it's a 150 ! The other carbs have a 190! WTF? This should not be like this correct?

[mcycle-nut]

I know this an old thread, but I was just looking up some info for my wife's '82 GS850's carbs. They are 45170 C1Z1, with 117.5 mains, 200 air jets, 42.5 pilots, 130 butterfly valves, and the choke is handlebar mounted. I just thought I would add this for interest to others as I see there was some question of what 45170s were off of. Originally I got a set of 82 "850" carbs to try, but the old paint pen scrawl from the salvage shop said "550", not 850, as I found out after some head scratching. No biggee, my good buddy owns the shop, so we'll figure something out.