MJN......Yoshimura reinvents the carburettor!

[Agemax]

very interesting reading.....

http://www.bikebros.co.jp/vb/sports/sfeat/yoshimura-carburetor-en/

[GS1150Pilot]

Super interesting! So one could convert existing carbs to MJN style. This is very cool!

[salty_monk]

Interesting concept, you can see the atomisation is better..

[sharpy]

Old tech in a newer VERY expensive carb. but still trick

[GS1150Pilot]

I just priced a set of TMR carbs for the 900f. The 900f carbs were always one of its weak points. For about $2K I could have perfect carburetion on it, and I think perfection is what I am aiming for over giant power. I want to keep the stock exhaust on the Honda (it is truly beautiful), but I will probably overbore it to 985 and then start working to make it run amazing between idle and midrange. Top end power will be a secondary concern.

[mmattockx]

very interesting reading.....

http://www.bikebros.co.jp/vb/sports/...carburetor-en/

That article is from early 2015 in case nobody noticed. What I gather is that this is only available for flat slide carbs and not the OEM CV type. While it's nice that they have this cool technology it is going to get extremely limited use if one has to spend thousands on fancy carbs to access it.


Mark

[Agemax]

That article is from early 2015 in case nobody noticed. What I gather is that this is only available for flat slide carbs and not the OEM CV type. While it's nice that they have this cool technology it is going to get extremely limited use if one has to spend thousands on fancy carbs to access it.


Mark

It seems to be a performance mod so why would anyone go to the trouble of fitting them to CV carbs?
Cant see really why it cant be retro fitted to any carbs, not just super expensive carbs?

[Chuck78]

My buddy had briefly described this to me quite a while ago, and it sounded pretty cutting edge. I did not realize that it was available as a retrofit custom setup for any carb rack! This is pretty groundbreaking still. Definitely on my radar, although I'm sure it is at least double the cost of a Dynojet kit!

[Greg B]

There was a company back in the late 80s, early 90s that was trying to market a similar type hollow needle.
I can't remember who it was, and I've gotten rid of all my old motorcycle magazines.
But I distinctly remember seeing advertisements for 'em.

[mmattockx]

It seems to be a performance mod so why would anyone go to the trouble of fitting them to CV carbs?

Better fuel metering is desirable for all carbs. Who doesn't want more power, better mileage, better driveability and throttle response? These might make it dead easy to convert to pod filters instead of the stock airbox, without the difficulty of jetting and getting everything working properly for those that aren't interested in doing that work.

Cant see really why it cant be retro fitted to any carbs, not just super expensive carbs?

Well, in the article Yosh only lists conversion services for Mikuni flat slide and Keihin CR carbs, nothing else. I agree that it should be possible in theory to retrofit it onto most carb types/styles/brands. They just don't seem to be bothering to work those details out.


EDIT - I went looking on Yosh's US site and they list these carbs for a few bikes. Most are small singles and the Ninja 250. The page for the Ninja carbs is here: http://www.yoshimura-rd.com/product/...-226-7000.asp?

Price for a two carb set is $1400USD, so a set for an inline 4 could easily be $2800USD. The Yosh Japan site does list a set of these in 41mm size for the 91-92 GSXR1100, so they should work on a 16 valve GS and would make monster power on a built 1100+cc motor I imagine.

Again, it's nice technology and I would love to see it available for classic bikes using OEM carbs instead of having to buy a set of carbs that cost more than the rest of the bike. It is too bad that it is priced such that very few riders will ever get a chance to enjoy the improvement in carburation it offers.


Mark

[bobtail84]

That is definitely some thing I would be interested in if there were a kit that would fit 33mm smooth bores. I have fitted MegaSquirt to several car engines and was toying with fitting MS to my 8 valve 1085 as it's quite do-able but if the MJN could be fitted it would keep the look and give better fueling... Hmmm where's my piggy bank.

[Chuck78]

In addition to the TMR carburetors that Mikuni offers which are amazing but cost a fortune, this multiple jet nozzle conversion kit is offered for Keihin 29mm smoothbore CR Special + 33mm smoothbore Keihin CR Special carburetors. Too bad I have two sets of CR 31 Specials!
Well, needless to say, I am now looking to trade up for CR 29 specials for the gs750 and CR 33 specials for the Rickman GS1000-1135cc, just so I can get this MJN conversion kit for them!

Yoshimura R&D USA left me a voicemail returning my email, I told me to call them about carb Parts, I emailed to find out if either kit for the 29 or 33 CR smoothboars would fit the CR 31 carbs. Have to return their call Monday.

920cc 10.5:1 pistons, mildly ported head, and Yoshimura Stage 2 cams... the GS750 will have quite a nice rebirth this next season! I'm looking to swap some RaceTech re-worked 89 GSXR1100K 43mm cartridge forks onto it at the same time, & 98-99 CBR900RR 310mm rotors and a new version of my Tokiko twinpot brakes to adapt to the early GSXR fork mounts! Should be a total blaster to ride in its newest (4th generation rebirth) incarnation!