Yamaha RXS100 recommended carbs

[JoeZN6]

Hello all,

 

I've just purchased an RSX100 but I'm struggling immensely with power. I'm getting 30mph at best and I can only fault the carb at this point.

 

The previous owner has installed an aftermarket carb of unknown specs and I can only assume this carb is not up for the job and I need to replace it.

 

My question is what is the OEM carb supplied with the bike? And do you know where I can purchase one from in the UK?

 

Alternatively, is there any aftermarket carbs that are highly rated for this bike rather than OEM?

 

Kind regards!

[Tinkicker]

Very likely the Mikuni VM26 with autolube port.  Cheap Chinese clones have flooded the market and are very hit and miss.  Some get lucky, most do not.

 

If you have a VM26 chinese clone, you will need to find the OEM pilot jet size, the main jet size, the slide cutaway, the needle jet number, the needle number and the float height that your bike came with new.

Change all these and your bike MAY perform as it should.  

 

However, there is no guarantee that even if you buy the correct parts that they will fit your carb.  It is highly unlikely that everything will just screw in.  Threads will be diffferent ect.

 

 I will start you off with 2 things you can immediately check in your carb.

 

Main jet #120 

Pilot jet. #17.5

 

 

 

Edited September 6, 2023 by Tinkicker

[JoeZN6]

Hmm it's a tricky one, I'll have to keep scanning the web to see if someone is selling one that came off the same bike as it should be good to go with a clean up and service. They're getting pretty rare now and like you said, you have to wade through the countless knock offs... Thanks.

[Tinkicker]

 

Took a bit of detective work but the Mikuni VM22 was fitted to the RXS100.  The confusion was caused by the fact that two versions were fitted, one is spigot mounted and one is mounted by a two bolt flange.  I assumed that the VM22 was flange only and the reason why I went for the VM26.  However it turns out that the 22 is available in either guise.  

 

Sorting carbs on older bikes is an absolute minefield.

 

Here is a used VM22 spigot mounted on ebay.  Looks like someone is desperate for it though.

 

https://www.ebay.co.uk/itm/Yamaha-Rxs100-Carburettor-Mikuni/204450816828?_trkparms=amclksrc=ITM&aid=777008&algo=PERSONAL.TOPIC&ao=1&asc=20221115143056&meid=8ccd707c39184d5382b34f53340ec41d&pid=101612&rk=1&rkt=1&itm=204450816828&pmt=0&noa=1&pg=4375194&algv=RecentlyViewedItemsV2&brand=Yamaha,parentrq:6eac66bb18a0a5487335bc77ffffc652|pageci:4204e583-4d55-11ee-99c5-f62fcc33df51|iid:1|vlpname:vlp_homepage&_trksid=p4375194.c101612.m4236&pageci=79efb318-cdf3-4ded-8704-f4ef3544e740&redirect=mobile

Edited September 7, 2023 by Tinkicker