Frostbite
TY 4 Stroke God
No, sorry it's not about Yamaha fitting all of our mountain sleds with a rear heat exchanger but this is a very significant issue.
Anyone who rode their RX-1 in areas with changes in elevation probably noticed something. As your sled gained altitiude it lost RPM on top. Right? If it turned 10,200 at a lower elevation you were lucky in some cases to get 9,500 RPM. We had all led to believe the four strokes were supposed to be LESS suseptable to elevation changes than our two stroke brothers.
Guess what? They are less suseptable! I called Barry Holtzman today to inquire about an ATACC system for my RX-1 Mountain. We had a nice conversation and he said it is ALMOST dialed in for the RX-1. There is an issue with the stock pilot jet size being too lean currently. A fix is on the way in either a shielded needle jet or fatter pilots.
Here's the reason for the making the post. This completley blew me away. It seems Yamaha completely overlooked something! The carbs on our sleds a vacuum activated. Right? Stick with me now. As you gain elevation there is less pressure and consequentially less vacuum available. It seems Yamaha never took this into consideration. What we currently have are carbs with slide springs that are too heavy for the lower level of vacuum to overcome at altitude.
Holtzman engineering has designed and is marketing (I just ordered mine) redesigned carb slide springs based on the altitude your typically ride. I think Yamaha should fix this under warranty but that may never happen.
Here's the deal. They have springs for 0-4,000 feet, 4-8,000 feet and 8-12,000 feet. The springs retail for $39 a set ($44 with shipping). He guaranteed I'd gain a 1,000 RPM by this very simple spring change. All I can say is WOW! Now I can throw more weight at my primary clutch and not have to clutch for the lowest common denominator. Hey, for 39 bones and 30 minutes it sounds like a hell of a deal. Powder Blue
Anyone who rode their RX-1 in areas with changes in elevation probably noticed something. As your sled gained altitiude it lost RPM on top. Right? If it turned 10,200 at a lower elevation you were lucky in some cases to get 9,500 RPM. We had all led to believe the four strokes were supposed to be LESS suseptable to elevation changes than our two stroke brothers.
Guess what? They are less suseptable! I called Barry Holtzman today to inquire about an ATACC system for my RX-1 Mountain. We had a nice conversation and he said it is ALMOST dialed in for the RX-1. There is an issue with the stock pilot jet size being too lean currently. A fix is on the way in either a shielded needle jet or fatter pilots.
Here's the reason for the making the post. This completley blew me away. It seems Yamaha completely overlooked something! The carbs on our sleds a vacuum activated. Right? Stick with me now. As you gain elevation there is less pressure and consequentially less vacuum available. It seems Yamaha never took this into consideration. What we currently have are carbs with slide springs that are too heavy for the lower level of vacuum to overcome at altitude.
Holtzman engineering has designed and is marketing (I just ordered mine) redesigned carb slide springs based on the altitude your typically ride. I think Yamaha should fix this under warranty but that may never happen.
Here's the deal. They have springs for 0-4,000 feet, 4-8,000 feet and 8-12,000 feet. The springs retail for $39 a set ($44 with shipping). He guaranteed I'd gain a 1,000 RPM by this very simple spring change. All I can say is WOW! Now I can throw more weight at my primary clutch and not have to clutch for the lowest common denominator. Hey, for 39 bones and 30 minutes it sounds like a hell of a deal. Powder Blue
fstblkwarrior
Extreme
That sounds cool. Do you think an ATACC would make a helpful difference for us flatlanders that occasionally go to different states to ride?
Frostbite
TY 4 Stroke God
I don't know that I'd spend $200 on an ATACC if I made one or two trips to the mountains each year. It's up to you I guess. For me where I ride from 2,000 feet to 8,000 feet continually changing elevation it makes more sense and perhaps makes the expense worthwhile.
The differences in the spring rates on the carb slide springs is what changes in the slide springs they sell. I wonder how they ever figured out that the springs were the problem? He just couldn't believe Yamaha missed that one in their testing. One thing Barry said was in testing the ATACC he was riding a RX-1 Mountain. He said his honest opinion was he'd never ridden a sled that pulled SO HARD in his Life! He was very impressed.
Now I have the new carb float bowls and the slide springs to change. He said the needle jet is uncovered on this sled and it was on some Skidoo models a few years back. Skidoo has added the shield back to their carbs. I wonder if Yamaha might want to consider doing that too? That could be another carb modification for us. Powder Blue
The differences in the spring rates on the carb slide springs is what changes in the slide springs they sell. I wonder how they ever figured out that the springs were the problem? He just couldn't believe Yamaha missed that one in their testing. One thing Barry said was in testing the ATACC he was riding a RX-1 Mountain. He said his honest opinion was he'd never ridden a sled that pulled SO HARD in his Life! He was very impressed.
Now I have the new carb float bowls and the slide springs to change. He said the needle jet is uncovered on this sled and it was on some Skidoo models a few years back. Skidoo has added the shield back to their carbs. I wonder if Yamaha might want to consider doing that too? That could be another carb modification for us. Powder Blue
PB with no J,
Do you have a website for the springs?
Do you have a website for the springs?
Buckeye
Lifetime Member
- Joined
- Apr 13, 2003
- Messages
- 1,430
- Location
- Lakes Region, NH
- Country
- USA
- Snowmobile
- 2018 Sidewinder LE XTX 137" 50th Aniversary
Springs
So is there any difference or advantage for us flatlanders in getting the 0 to 4000 spring???? :?: :?:
So is there any difference or advantage for us flatlanders in getting the 0 to 4000 spring???? :?: :?:
Nothing will help the silver ones, Uncle Buck.
- Joined
- Apr 17, 2003
- Messages
- 5,346
- Location
- Menno, SD
- Website
- www.ulmerracing.com
- Country
- USA
- Snowmobile
- 2014 Yamaha SR Viper LTX, 2014 Yamaha SR Viper RTX SE, 2015 Yamaha SR Viper MTX SE 162 (turbo), 2015 Yamaha SR Viper MTX SE 153
- LOCATION
- Menno, SD
- WEBSITE
- www.ulmerracing.com
Some people were cutting 5 rings off of the spring and then putting them back in and this picked up the throttle response quit a bit, not saying it's a sure thing, but that's also something to think about.
Buckeye
Lifetime Member
- Joined
- Apr 13, 2003
- Messages
- 1,430
- Location
- Lakes Region, NH
- Country
- USA
- Snowmobile
- 2018 Sidewinder LE XTX 137" 50th Aniversary
Springs
Uncle Ray(Formerly a Master),
Silver ones don't need any help to be better than the BLAH Blue ones. Are you all done riding for this winter? Hey did you notice I got my Pro status back. :lol: :lol: :lol:
Uncle Ray(Formerly a Master),
Silver ones don't need any help to be better than the BLAH Blue ones. Are you all done riding for this winter? Hey did you notice I got my Pro status back. :lol: :lol: :lol:
therxwon
Newbie
I know someone that tried the springs @ 6000ft and gained 700rpm.
Frostbite
TY 4 Stroke God
It sure seems like a simple fix doesn't it? It's too bad Yamaha didn't figure this out. I think it may have helped with the RX-1's reputation in the mountains. After climbing with this sled and constantly fighting the track ratcheting. When the power was going to the track these sleds rock. It's too bad it ends up being our job to make that and the RPM fix happen. Maybe it's not too late for Yamaha to put different springs in the 04's and ship us 03 guys a retrofit kit? Powder Blue
link
Newbie
- Joined
- Apr 17, 2003
- Messages
- 24
I'm going to test this theory next week and I'll let you know how it works.
Kind of funny. I gained rpm and throttle response from stiffer springs.
Frostbite
TY 4 Stroke God
Mr. Yamaha if you're running at a low elevation you probably could have gained with stiffer springs. I'm sure the springs that are in there are the ones used in the R-1 motorcycle and are a compromise of some sort for all altitiudes encountered by the bike. If you are at a lower elevation than their target elevation (2,500 feet for instance) you could need stiffer springs. Maybe Holtzman's springs for low elevation are stiffer? I was just interested in higher elevation springs wwhen I spoke to him so the topic never came up. My new springs are here. I just need to install them and my new float bowls. Powder Blue
Similar threads
