[Niko.R]

I have been excited about what I've been reading about Mikuni RS carbs and their effects on the bike's performance. I've seen some videos online of people getting lucky and plugging these into old bikes, and they seem to get lucky and run great. I have an '82 Suzuki GS550. I'm thinking of replacing my cv carbs for the Mikuni RS34s. I have done a ton of searching online and could not find much information at all on matching Mikuni RS carbs to a specific bike and how to tune them after installation or if it will require tuning after installation. Do any of you have any experience/resources swapping these out on old bikes?

 

[TrialsRider]

You could be the first

 

[TrialsRider]

... I have done a ton of searching online and could not find much information at all on matching Mikuni RS carbs to a specific bike and how to tune them after installation ...

Sudco Mikuni has a comprehensive tuning guide on the net somewhere. I think it's a pdf

Your bike doesn't have weird 2 barrel carbs like some did, I doubt you'll see a lot of difference just by going to flatsides but they sure will look pretty.

 

[dirkchecken]

to big. a 34mm flatslide does not equal a 34mm cv type. just throw a bucket of gas in the intakes. i have a set of those on a kaw 810 with 10:25 cr and higher lift gpz cams. and they are a lttle big, the price was right thou(300). i did have a set of keihin 29 crs on it before that ran better, those i sold for a lot of crust. keihin crs can be bought in size 26mm, but are 1k plus. maybe a set of round slides off a gs750 . if the spacing lines up.

 

[dirkchecken]

oh. being that the only performance parts that can be found are a pipe ( andnot a good one) and maybe a dynojet kit. people just put on a gs650 top end, carry on

 

[crazypj]

The GSX 550 (4 valve motor, 16" front wheel) had the dual slide carbs, same as Kawasaki inline 6 Z1300.
Earlier GS550 motors used to have a lot of parts available in Britain but no idea of US market (people just got a 750 or 1000)
I built GS550 for a friend out to 720cc, bored slide carbs, MUCH faster than the 'brand new' Honda VF750 that came out a few months earlier.
He sold it to get an RG500 and went racing.

 

[Niko.R]

Sorry about your experience with the Mikuni RS34s on your bike. According to this Australian company, they can be tuned to fit a GS550:

Mikuni RS 34mm Carb Kit Suzuki GSX650E and GS550E | Mikunioz

I'm going to call up them and see if the jetting they're using is what comes stock when you by the RS34 from Mikuni. Because if all I have to do is adjust the on-center spacing, then I'm not going to pay these Aussies an extra 300 bucks plus shipping for that adjustment.

 

[TrialsRider]

pretty sure dirk is speaking from track racing experience
... almost any carbs could be tuned to work on almost any engine, it's a matter of what power you want and where in the power band.

 

[dirkchecken]

Sorry about your experience with the Mikuni RS34s on your bike.

no need, i didnt say they where bad, just didnt work as good as the keihins. you should buy them and i hope you get them to work. got to be better then the old cv stock carbs. post a update.

 

[Niko.R]

Oh gotcha! Ya, I see now. Ya you nailed... I'm hoping for better than stock. I'm not racing this bike, but I love some twisties and so any modest improvements will be appreciated. I was watching some youtubes to learn about differences between round slide and flat slide carbs. The stuff is fascinating. Racing flat slide carbs will be def upgrade from stock if they're actually tuned like they say they are because I'm hoping not have to fiddle with them after they're installed.

Turns out the Aussie's kit is legit. I called Sudco this morning. He explained the bits and pieces that are custom on it to fit the GS550. It makes me feel better about saving up for the extra cost.

I just got a new job and have to save some $cratch for the Mikuni RS34 kit. I rebuilt the engine and got new cams that are in spec. Then I painted the engine. Still need to get the bits for the front end swap with a gxsr and figure out what I want to do for the rear suspension. The pandemic brought this project to a standstill for a long time. I'm excited to make some progress again. I'll def post an update. I might see if there are some project threads and start one for this bike.

 

[brad black]

34 sounds nuts big for a 150cc cylinder that doesn't make a lot of power. be interesting to see how it works.