Any info on what carbs will fit an 81 850g?

[devilman]

Like the title states, looking to see what carbs will fit an 81 850g with little to no modification. I took mine off to clean them and whoever was in there last screwed some stuff up and I cant even be bothered with them. Just trying to figure out what might fit so I can grab another set. thanks in advance

[duaneage]

I believe they are 34 mm Mikumi CV carbs. A set from a 1000 would work as long as you re jetted them. A set of rebuild kits come with the jets needed and you would be well advised to rebuild them before use anyway so if you got carbs from a larger bike that were the same size they could be retrofitted,

Namco has the jets and needles included in their kits, along with new parts most kits don't have.

[Steve]

Actually, the 850 uses BS32 Mikunis.

All the '80-and-newer GS bikes from 550 through 850 used the 32s, but with different jets.

The 1000s used the 34s, 1150s used 36s.

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[duaneage]

well that widens the scope a bit, and if he gets carbs from another size engine he can set them up with the proper rebuild kits.

[67fire]

The 34CV's are a perfect match. And a great up-grade to the factory 32CV's. I had them on my '81 850 as well.
A little fine tuning and you will be set!

Eric

[duaneage]

Yeah, there is always that. I found a set of 34s on a 82 GS850G I parted out. With proper intake boots it's a step up in airflow and fuel delivery. The 650 was the ideal sized engine for those carbs, at 673cc they seem perfectly matched to the application.

I have a 400 Yamaha with 34 mm Mikuni CV carbs. It's funny to see the bigger carbs on a smaller bike but each jug is 194cc so it's matched pretty well.

[devilman]

I appreciate all the info I have recieved thus far, never expected to check back this soon and see this much. I am going to start checking ebay. I would like a bit more out of the bike, would stepping it up to the 34 be the best bet for it? thanks again and I look forward to any more suggestions you guys may have

[rustybronco]

I think you will be tied to using carbs from the years of 80-81, because of the choke inkage.

[Steve]

... I would like a bit more out of the bike, ...

Yeah, there is a good-sized bunch of us that would like more, but look at the facts: the 850 has probably the worst power-to-weight ratio AND it's the heaviest GS, except for the fully-dressed GK. On the other hand, it's also one of the smoothest and most reliable. Yeah, more power would be nice, but how much is it going to detract from an otherwise nice bike. It's going to be difficult to make it a tire-shredding wheelie machine, and has quite a bit of performance in stock trim.

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[devilman]

I don't want my intentions to be confused. I am not looking for a "tire shredding wheelie machine" by any stretch. if thats what I wanted I would have never sold my roadwarrior 1700. I would just like a bit more out of the 850 and if bumping up to the 34's, when i need to do a lot of work to my current carbs any way, can do that then great. I

[flyingace]

You weren't too specific on what's wrong with the current carbs. But unless they are completely beyond repair (as in cracked or bent), I would just repair them. You can get some additional performance by raising the needle a notch or two which improves the mid-range. The stock setup is a little lean there. Search other threads on shimming the needles on the stock carbs.

And to editorialize a little, bigger carbs aren't necessarily the answer. Bigger carbs require more air velocity, in other words higher RPM. I've never found the 850 to be lacking in power above 5K. You may find you actually lose mid-range punch for some extra power at the highest RPMs. This may translate to more HP, but not more useable HP.