ask the yamaha engineers 2004 models

RX Clutching
Yamapower
Hi, Thanks for the open forum.
I am considering sno-checking a 04 Warrior and am concerned about the stock clutching being as soft as the 03''s RX1 was. I really prefer not to purchase a $250 clutch kit to make it run with the 800''s.
My question being...is the ''04 clutch (Warrior) more agressive?
Thanks again.
Yamaha_Rep
Yamapower:
Our engineers developed the '03 RX-1 clutching to work well under the following conditions: Properly broken-in stock engine, production track, on hard-packed snow. Our performance data shows the quickest acceleration when the shift RPM is slightly below 10,000, and then revs to 10,200 at maximum top speed. When compared to a stock SRX 700 (3-3 2-stroke) under controlled conditions, the RX-1 was consistently faster. Now, if you started your tuning procedure by modifying the RX-1 with a new track, 144 studs and started tuning before the engine was completely broken-in, your results may be different. Not to say that you can't tune the RX-1 for increased performance - some people can - but we have to base the production calibration on what we produced, not on how it may be modified.
Now, in answer to your question - The RX Warrior has larger diameter clutch rollers, a stiffer driven clutch spring and a lower chaincase ratio to allow the engine RPM to rise quicker to work better with the longer Rip Saw track. Increased traction requires a different clutch calibration for greater acceleration.
Hope that helps, Thanks, Yamaha_Representative

RX1 vs. Warrior
SFC
I'm torn between the RX1e/r and the Warrior. I'm a midwestener(flatlander), I ride 30% trail, 70% lakes with alot of friends with XCs, ZRs, REVs.
Which RX is going to serve me best, and give me the performance to be out front? Help ...
Yamaha_Rep
SFC:
If you spend your time on the lakes running against your buddies for max top speed, I would go with the RX-1 - The RX-1 is slightly faster at top speed on radar. If you run the lakes to play in the bays in the fresh powder, I would go with the RX Warrior. For me, both sleds have plenty of top speed, so I would go with the RX Warrior for the increased traction (i.e.: acceleration) and increased versatility if the trails get rough or if there is a foot of fresh powder.
Thanks, Yamaha_Representative

Where do you see the Warrior
Mighty RX-1
What I mean is, where do you see it fitting in best, trails, lakes, hill climbing? I would think it might be a little bit too much track for us midwesterners that have hard packed trail conditions. My 121 can be hard to steer sometimes coming into a corner that''s all iced up when my mega bites do indeed bite.
Yamaha_Rep
Mighty RX-1:
The RX Warrior has greater traction (due to the longer track) than the 2004 RX-1. The benefit of this additional traction is greater acceleration under a wider range of snow conditions and the longer track 'bridges the bumps' for greater ride comfort. From my experience, the RX Warrior has the versatility to provide optimum handling and surprising comfort over a broad range of trail conditions, especially if you run without studs. Plus if (when) we get a fresh dump of 1 foot powder, the RX Warrior has increased floatation. The primary trade-off is a reduction in how 'nimble' the sled is. So, unless I rode mainly on very tight trails, or wanted the absolute maximum in top speed, I personally would choose the RX Warrior.
Thanks, Yamaha_Representative

2004 Mountain Sled Improvements
tmk50
I''m glad to see that you made an effort to shed a few pounds on the mountain sled and address our (customer''s) complaints about the handwarmer memory. I have a few more questions about the 2004''s.
Will the 2004 Mountain RX1 be fitted from the factory with different float bowls on the carbs to address the ''cutting out'' problem that we have been seeing on steep slopes?
Why doesn''t the RX1 come with a valve to control the flow of coolant to the carbs like your other sleds? I''ve had some problems on warm days at high altitudes with the carbs being too warm when I try to re-start my RX. I think a shut-off valve would help.
Are you changing the swaybar/links on the Mtn RX1, or are the changes only on the Warrior and the shorttrack?
Did you change the suspension spring rates on the mountain RX1?
Yamaha_Rep
tmk50:
In answer to your 'float bowl' question:
Yes, the 2004 RX-1 Mountain will be getting new float bowls that have a separate 'fuel room' inside the float bowl to hold the fuel around the main jet while climbing at a severe angle. Go to the Tech Notes archives to see a photo of the new float bowls, or copy and paste this link:
http://www.amsnow.com/article.asp?id=4899
These bowls will also be made available to 2003 RX-1 Mountain customers if you have experienced that phenomenon. See your dealer for details.
In answer to your 'coolant valve' question:
The reason for the coolant flow to the carburetors is to control carb bore icing. In fact, we have two systems - an electronic heater that automatically shuts off based on temperature and the system you asked about that routes coolant around specific areas of the carburetors. At this time, our testing has not found any 'start-up' advantage to shutting off the coolant flow, but we may study this area in greater detail in the future.
In answer to your 'swaybar/links & suspension' questions:
Yes, we will be changing both the front suspension spring rates and installing the longer swaybar link on the RX-1 Mountain for improved deep snow agility and function. The swaybar diameter remains at 10mm.
Thanks for your questions, Yamaha_Representative

smaller 4 strokes?
redF5sp
Will Yamaha have anything to offer in smaller displacement fourstrokes in the near future.
Yamaha_Rep
redF5sp:
Yamaha has many advanced R&D projects to study possible future directions in chassis, components and engines but, as with any of our competitors, we can not comment on future products until they are ready to be released to the public.
Thanks, Yamaha_Representative