Topic: New Mikuni ?? for cb750??? gives Kehien CR compition?

[NitroHunter]

But Frank think of all the fun you're missing by using those Webbers!   

[MRieck]

Flatslides typically are poor for street use. There are some issues at anything below WOT.
At WOT, however, they are superior... which is why they are used most commonly on racebikes.
If I were building a cb750 racebike, I might look into these, because at the end of the day, a difference in a few hundred dollars for components is minimal, in terms of racing.

  Mark I've had good results with both Mikuni RS's and FCR's on the street. Great idle and excellent power. One of the things I learned is the accelerator pump needs to be adjusted to work at a specific throttle postion with a specific duration....it is key. The RS carbs have a better system to adjust both timing and duration compared to the FCR's. the FCR's offer much more adjustability plus the floating slide. The pull on the FCR's is really nice and they "whistle" as you open the throttle. Nice.
 Both of these carb systems require a good background in carb tuning knowledge. They can both work very well but you need to know what you are doing.

[mlinder]

Flatslides typically are poor for street use. There are some issues at anything below WOT.
At WOT, however, they are superior... which is why they are used most commonly on racebikes.
If I were building a cb750 racebike, I might look into these, because at the end of the day, a difference in a few hundred dollars for components is minimal, in terms of racing.

  Mark I've had good results with both Mikuni RS's and FCR's on the street. Great idle and excellent power. One of the things I learned is the accelerator pump needs to be adjusted to work at a specific throttle postion with a specific duration....it is key. The RS carbs have a better system to adjust both timing and duration compared to the FCR's. the FCR's offer much more adjustability plus the floating slide. The pull on the FCR's is really nice and they "whistle" as you open the throttle. Nice.
 Both of these carb systems require a good background in carb tuning knowledge. They can both work very well but you need to know what you are doing.

I had em on my race r75/5 back in the late 90's. Well, some mikuni flatslides, can't remember the model. Tried em on my street r75/5. Just couldn't get the midrange dialed in well no matter what I did. Went back to the bing CV after a bit. Maybe it was the carbs, maybe it was just me, I dunno.

[nippon]

I have bolt on some of these carbs to a customer bike two weeks ago and i'm totally impressed about these carbs according to outstanding quality, easy to setup, perfect fit and perfect working choke system. Real "drop-in" carbs with stock insulators. Especially the bottom torque of the engine is outstanding and customer can't stop to smile anymore during his rides. I have opened up the bottom air filter housing around the filter heavily and the bike has 132.5 main jets.
Perfect from low to high rpms. If you can afford them, the decision is clear.
The bike has 836ccm, Webcam 41A and some moderate headwork. With stock carbs 68.5 hp at the rear wheel. So we are looking forward to make the next dyno run with these carbs.
Results will be posted.

nippon

[754]

I am just not warming up to the angle of the float bowl joint..

[MRieck]

I am just not warming up to the angle of the float bowl joint..

It works out fine....that angle allows the bodies to be used for downdraft heads with different bowls. FCR's are like that too.

[754]

I know it probably works..  Just  could look a lot better.. They do have bowl drains? If not changing jets would be messier..

[MRieck]

There is that 17mm nut on the bowl that gets you right to the main. Works out well unless you have no clearance underneath the carb.

[brandEn]

I'm confused are these carbs different than the Mikuni's Cycle X offers?

[Leino]

I'm confused are these carbs different than the Mikuni's Cycle X offers?

These are TMR, Cycle X sells RS's.

[nippon]

I changed all four main jets from 135 to 132.5 within 5 minutes. Just open the 17mm nut and you have plenty of room
to screw out the main jets. Throttle response is awesome with the Mikunis. Starting is great, too,... a small finger tip and all four cylinders fired up super fast. I'm really impressed. I guess, they add min. 7-8 hp. So. I'm looking forward to the dyno run.
The only problem is right now, that i need them for my K1 and Seeley, too.

nippon

[Stev-o]

A 7hp increase would be very impressive. 
I love the Mikunis on my Z1.

[Tews19]

I think the angle of the bowls are great. Something different that one doesnt get to see everyday

[bollingball]

I changed all four main jets from 135 to 132.5 within 5 minutes. Just open the 17mm nut and you have plenty of room
to screw out the main jets. Throttle response is awesome with the Mikunis. Starting is great, too,... a small finger tip and all four cylinders fired up super fast. I'm really impressed. I guess, they add min. 7-8 hp. So. I'm looking forward to the dyno run.
The only problem is right now, that i need them for my K1 and Seeley, too.

nippon

Maybe they are cheaper by the dozen

[lucky]

If you get a VMax make sure to get the older one that has a steel tubular frame,
like a Ducati, NOT the new piece of crap with the silly headlight and aluminum junk frame.

IF you get a VFR get the VF1000R with gear driven cams and make sure it has the line bored cams too. Late 85 or 86. It was only made for two years.
121 HP!

CLICK on the photo for a larger version.

[crazypj]

Flatslides typically are poor for street use. There are some issues at anything below WOT.
At WOT, however, they are superior... which is why they are used most commonly on racebikes.
If I were building a cb750 racebike, I might look into these, because at the end of the day, a difference in a few hundred dollars for components is minimal, in terms of racing.

  Mark I've had good results with both Mikuni RS's and FCR's on the street. Great idle and excellent power. One of the things I learned is the accelerator pump needs to be adjusted to work at a specific throttle postion with a specific duration....it is key. The RS carbs have a better system to adjust both timing and duration compared to the FCR's. the FCR's offer much more adjustability plus the floating slide. The pull on the FCR's is really nice and they "whistle" as you open the throttle. Nice.
 Both of these carb systems require a good background in carb tuning knowledge. They can both work very well but you need to know what you are doing.

 Flat slides are great when matched and set up properly, problem is, when not set up 100% for motor they are almost as difficult as 3 jet Kei-Hin to get right

[MRieck]

Flatslides typically are poor for street use. There are some issues at anything below WOT.
At WOT, however, they are superior... which is why they are used most commonly on racebikes.
If I were building a cb750 racebike, I might look into these, because at the end of the day, a difference in a few hundred dollars for components is minimal, in terms of racing.

  Mark I've had good results with both Mikuni RS's and FCR's on the street. Great idle and excellent power. One of the things I learned is the accelerator pump needs to be adjusted to work at a specific throttle postion with a specific duration....it is key. The RS carbs have a better system to adjust both timing and duration compared to the FCR's. the FCR's offer much more adjustability plus the floating slide. The pull on the FCR's is really nice and they "whistle" as you open the throttle. Nice.
 Both of these carb systems require a good background in carb tuning knowledge. They can both work very well but you need to know what you are doing.

 Flat slides are great when matched and set up properly, problem is, when not set up 100% for motor they are almost as difficult as 3 jet Kei-Hin to get right

A good A/F system (WEGO etc) works well for set up

[brandEn]

Are these things really $2000?

[crazypj]

If you get a VMax make sure to get the older one that has a steel tubular frame,
like a Ducati, NOT the new piece of crap with the silly headlight and aluminum junk frame.

IF you get a VFR get the VF1000R with gear driven cams and make sure it has the line bored cams too. Late 85 or 86. It was only made for two years.
121 HP!

CLICK on the photo for a larger version.

 I've had to switch out gear drive, it's just as much junk as the chain
As for angled float bowls, yeah, real good idea to have semi downdraft carbs mounted wrong
 Butt dyno is just a guess, I've seen way to many bikes the 'feel fast' but are actually slower than stock

[PeWe]

Like these... 
http://shop.yoshimura-jp.com/en/product/syousai.php?id=13653

I really wanted them until I saw the price tag...   did my old VM29 project with OEM inlet rubbers instead of fulfill the wonderful dream