No Dynojet carb kit coming for the RX-1 at this time.

[Frostbite]

Those of you who ride motorcycles have probably heard of "Dynojet Kits" for motorcycle carbs. They have built carb kits that enhanced the performance of motorcycles and other motorsports vehicles for years. I installed one of their kits on my V-65 sabre years ago and couldn't believe the difference. The bike ran smoother, pulled harder and got better economy. I E mailed Dynojet today and here's their reply. I may have messed up though. I failed to tell him that this is a four stroke snowmobile with Yamaha's R-1 motor in it. I'll answer him and provide some more specifics. Perhaps he'll change his tune? Powder Blue

Unfortunately, we don't plan on making any jet kits for snowmobiles as of right now. I apologize for the inconvenience.
Regards,

Ross Hunsaker
Technical Support
ross@dynojet.com 1-800-992-4993
www.dynojet.com
DYNOJET RESEARCH, INC.

To: yamahatech@dynojet.com
Subject: Yamaha RX-1 snowmobile jet kits?

Do you plan on making a jetting kit available for the new Yamaha RX-1 snowmobile? I have an RX-1 Mountain and I'm looking for few more H.P. at a reasonable price. Thanks.

 

[Silver Streak]

I talked to a tech at Dyno jet a while back and he told me the same thing. No snowmobile stuff. I used to race FZR1000's and the stage III jet kit was the first thing to go in.The power increase was great. While I was talking to the tech I asked if I could use an R1 kit and he said if the carbs are the same, he didn't see why not. I just haven't dug deep enough to tell if the R1 carbs are the same before they went to the fuel injection. I do know when I put the kits in, the springs were weaker for better throttle response. PB said that is what Holzeman is doing for the RX1 carbs. Sounds like they are working for the same goal.
SS

 

[Frostbite]

I spoke to a supposed "Tech" at Dynojet. He seemed rather intimidated to working in a non scripted area. Yes, they have an R-1 kit. It's $122.22 and consists of quite a few carb parts.
Yes, the 00 and 01 R-1 motorcycles used vacuum operated carbs but they are mounted differently and also use a different type of fuel pump to the best of my knowledge. To say the carb kit would work would be a stretch.
Does anyone know what carbs the R-1s used before going to fuel injection? The RX-1 carbs are Mikuni BSR37. Are the R-1 the same? If so we may have found a very inexpensive horse power increase.
Powder Blue

 

[rxrider]

Powder Blue - A Dynojet kit for the Yamaha FZ1000 may work on the RX-1 as they both have a rack of Mikuni BSR37 carbs.

Engine Technical High lights for FZ1000:
YZF-R1 based powerplant tuned for more low to mid-range power
Maximum power 143.1 HP @ 10,000 rpm
Maximum torque 10.8 kg-m @ 7,500 rpm
4 x BSR37 carburetors

I've found that Dynojet makes a kit for this streetbike that may as well work on the RX-1.

Check out http://dynamic.dynojet.com/cfml/Jetkits/yamahajets.cfm

 

[Frostbite]

So, am I going to have play Guinee Pig again? I probably will but, it sure would be nice if someone who asphalt or grass drags would try it first. It's cool to know the carbs are the same. Powder Blue

 

[Vmax4]

Dynojet

Hey, you got me interested, but I too am not interested in being the first. I put one of these kits on my Harley. It was a piece of cake, and supposively added a bit of a boost, BUT I contributed that to the fact my harley had a metal slide, and part of what sold me on it was that the plastic slide would lift faster and make it more responsive to opening the throttle, more air, more go. What do you guys think? Other than that all the kit was, a spring, few jets, yadda yadda yadda...........

Thanks, Steve Burdick

 

[Silver Streak]

I looked at the dyno jet site a while back and I still can't see a kit that will work. The older FZR's have a totally different carb than ours. I don't know about the newer R1's but they only offer a stage I kit for these. That won't get rid of the huge air box. That is what I'm after. Did I miss something on the dyno site?
SS

 

[Frostbite]

Man, the parts list on this kit is sure pretty big. You get
(4 each)-130,132,134,136,138 main jets. (total of 20 jets)
4 needles
4 E clips
4 adjusting washers
4 needle springs
4 pilot jets
1 drill bit for removing carb plugs
1 screw to screw into the plug once you've drilled it to use as a handle to remove the plug.

I guess I'm used to Yamaha pricing. This sounds like a good deal just for the parts alone let alone the R&D work that went into developing this kit. Think what it owuld cost if Bender was selling it Powder Blue

 

[Birdman]

You might want to check into a FZ-1 . I think that bike has about the same carbs as a RX-1

 

[Vmax4]

Powder Blue, consider this.......... The air screws are already left unplugged on the RX1 so you don't need the drill and screw. I have messed with jetting a little on my sled and found it runs best on the 135's, so you might not need any of the main jets. The only thing you will use is the 4 needles. Doesn't sound like a great deal to me. I am not sure this is the way to go. Just my first thoughts.

 

[Buckeye]

Needles

I would want to look at the profile of the needles. They are meant for the bike which is operated at temps in the 80's. I think they may be profiled for leaner running and could be a too lean for running at zero degree temps. As far as the main jets, I think you can never have too many to tune with. I know the dynojet kit worked well on my Harley, but the addition of the Yost power tube made it even better. I wonder if we could get Yost to make needle jets for the RX-1. Although I think they only do Harleys. :roll:

 

[jtssrx]

Jet size Be careful

I was talking with Larry at North county Yamaha about this kit. He uses there kits in his street bikes. When you use the jets fromdynojet you must use a jet that is three to five sizes bigger then a yamaha jet due to the way they are made.

 

[grapeape]

I will check yomorrow to see if the Rx needles cross match any of Yamahas other vehicles, as the needle taper is very important...

 

[Frostbite]

I haven't had a chance to check in for while. It's nice to see you guys are on the same track as to what I was thinking. It's the needles where the changes are the most dramatic. Now I have the new carb slide/vacuum springs. My jetting is just fine. I really had planned to ask Barry Holtzman about the needle design on the RX-1; if it could be bettered? I haven't had the chance to yet.
I tried to convince Dynojet to let a few of us "Prototype" jet kits for them. They have absolutely no interest in snowmobiles at this point. I explained to them that the RX-1 was the #1 selling snowmobile last year and the very first PERFORMANCE fourstroke. That this was perhaps the wave of the future and there was some serious money to be made here since these sleds were the top of the line model and owner typically spend thousands on accessories. I got this ho-hum attitude back from this guy until I said; guess what else? It's rumored Arctic Cat may use the Hyabusa motor in their sled next season. At this point the guy said " holy F#*%! That would be insane! Let me speak to my supervisor and I'll get back to you. I'm still waiting. Powder Blue

 

[Silver Streak]

PB;
Where did you hear about the rumer of the Hyabusa? That would be some serious power. I'll ask a friend of mine I used to race with that works at the local suzuki shop.
SS