RS34 jetting

[Guest]

I just picked up a set of used RS34's off of a GS1000 on ebay, and I'm trying to figure out what main jets I should be using.

I have an '83 GS1100 with a stock motor other than a V&H 4-1. Currently have the baffle in but I may consider removing it down the road.
Thank you in advance!

EDIT: I'm at sea level

[trippivot]

around 120 / 122.5 or may need to go up to 127.5. no baffle? maybe as large as 135 -- it is hard to just throw a number out with out knowing the elevation as well as the engine mods.


The RS34-D21-K - came new with 115 mains and 17.5 pilot but they were jetted for GS750/KZ750/GSXR600

the pilot 17.5 should be fine - around here the needle works best at 1 below middle groove. - but that too could be different where you are.

[DFWSpeedster]

Also, as far as air filters go, are the K&N filters REALLY worth it for how much they are?

[DFWSpeedster]

I'm at sea level, I guess I'll just have to play with it. Luckily jets are cheap.

[JJ]

Also, as far as air filters go, are the K&N filters REALLY worth it for how much they are?

You can get APE pods for about half the price as the K&N's. I haven't tried them myself, but other members say they are as good as K&N. I use the K&N stock replacement filter in the stock airbox, and it's worth every penny to me.

[OldVet66]

You don't want to remove the baffle. Mine came loose dropped out lost forever. It was obnoxiously loud. Drove it home parked it and waited for a new baffle to arrive. As for the jet sizes you could look up a Dynojet stage-3 kit and use a conversion chart to get the Mikuni jet, equivalent sizes, they provide in the kit.

[DFWSpeedster]

Just checked Dynojet and for the stage 3 with baffle in they recommend DJ138. The conversion tells me those are 130 Mikuni equivalent. Does that sound right?

[OldVet66]

I would rely on the Dynojet recommendations. I am running VM carburetors with the DJ 142/Mikuni 133.1 jets. I am not familiar with your carburetors so I would just be guessing. I do know the main jet needles provided with my kit provides for smoother transition than a stock needle could. That information from the kit gets you in the ballpark.

[trippivot]

K&N are worth the money - I have a set that are almost old enough to drink alcohol. keep cleaning them --

plenty of other brands - foam are cheapest and easy to clean/oil.

Now you own a set of mikuni mechanical radial flat slide carburetors - forget dyno-jet - they specialize in CV carburetors. jet numbers are all wrong too.


Mikuni tuning manual is a PDF online - RS series use the HS40 link.. you have what I believe to be the the best - most tunable carburetors under the sun- and every part ( should you need one) is available thru sudco or mikuni or K&L - there is an information overload at the other side of the links.

http://www.mikunipower.com/RS01.htm

http://www.mikunipower.com/Manuals01.htm

[DFWSpeedster]

Awesome. Thank you for those! The RS36 chart for the GS1100 recommends 130 mains, so I think I'll go with those.

As for the idle mixture, only 1/4 to 1/2 of a turn? Someone else said 2-3 turns out

These carbs were always out of my price range, but after batting the float height with the 34mm carbs off of an 1100 katana I finally gave up and found these for roughly $400, and they look almost brand new!

[Joe H]

The idle mixture screws work completely differently than those on CV carbs, I don't think 2 or 3 turns would be correct for RS's.
They are easier to tune than CV's each circuit works a bit more independent and over laps as you move from idle to redline.
Also put marks on your throttle grip at least at 1/4, 1/2, 3/4 so you know which circuit you are working with while you tune.

[DFWSpeedster]

Hm, now I'm confused. This was taken from the tuning guide:

TUNING THE IDLE CIRCUIT (PILOT SYSTEM)The first step in tuning any carburetor is to getthe idle circuit correctly adjusted. And, the first step inthis procedure is to adjust the pilot screw position for bestidle. Mikuni sets the pilot screw at three turns open duringassembly. This is the position we have found to be rightmost of the time. If the screw position has been altered,gently bottom it and re-open to three turns out.

[Joe H]

If thats what it says thats what it says!
You will know right away, it shouldn't make too much difference to get it running, then tune the screws for highest idle.
I always thought 3 turns on RS series carb meant go down a size on the pilot jet. But follow the directions.

[DFWSpeedster]

We'll know hopefully in a few days after I put everything back together, just trying to do everything I can without them on the bike. We'll see! Thanks for the throttle grip marking idea!

[Joe H]

Keep in mind ( Im sure you know) that CV carbs are RPM dependent and the RS's you have are Throttle position dependent…. Don't use CV tuning tips for RS carbs.
Other here have to know a lot more than me about timing RS's