Hi again! I recently installed a MBRP Race can on my viper and its apparent that the mid-range sounds a little flat (I thought that when I had the stock can on it). The sled has about 8K miles on it, but it was very well maintained and ridden on Canadian trails most of its life. I've thoroughly cleaned the carbs and the exhaust valves. I'm thinking that the clutch might need a rebuild, or maybe I'm just psychotic about how my equipment runs. Attached is a video of some field riding in hopes that it can shed some light on the performance or the lack there of (sorry for the crappy video, I was holding my phone. lol). I appreciate any feedback. Thanks!
Please note** I'm basing my inquiry from videos of other vipers with the same stock setup and a MBRP Race Can. They sound way more snotty than mine.
Please note** I'm basing my inquiry from videos of other vipers with the same stock setup and a MBRP Race Can. They sound way more snotty than mine.
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2003VIPERER
New member
couldnt get the video to load. are you basing this on sound? could be alot of factors that play a part in this.
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Have you personally checked the power valves and their travel?
Mac
Member
My guess nothing wrong nothing changed. Because it sounds different your thinking you should have different results. If you are not testing with timers there will be no way to measure change.
mod-it
Member
Agreed. A can is only going to change tone and offers no performance upgrade.
A flat feeling mid-range to me is clutching.
A flat feeling mid-range to me is clutching.
A couple of bucks
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I just re-read the OP. A few times to be completely honest..... and I'd have to agree w/ the above. Now that I actually chewed on what you typed.
Thanks for the responses. I’m sorry about the video not loading. I’m still thinking I’m missing something. I cleaned and set the exhaust valves to Yamaha specs (using a 3.5mm wrench), cleaned the carbs and reset the fuel screws, all three plugs are burning clean and equal. I just seem to be missing midrange power. I raced my buddies bone stock ‘06 Ski Doo MXZ 600 SDI and he smoked me off the line (he has a 1.5 ripsaw) and kept pulling away until about 400 or more feet then I seemed to gain a little before we let off. I don’t have much experience with Yamaha 700 triples, so I don’t know what I should expect. I just thought I should beat his 600. Maybe I’m wrong.
Vincent
New member
You shouldn't have gotten smoked like that.
I own a less powerful 700 red triple with 18 500 kms and recently got to drag race a 2014 ski doo 600 Eteck Renegade. Surprisingly we were basically even start to finish.
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time to pull and clean the clutches. has it been clutched to your knolwege? stock clutching from that era can leave a lot of performance on the table.
I'm not sure about the clutches. I really don't know what to look for in regards to normal wear. He did mention to me that he replaced the spring early on because of issues with them breaking. Thanks
Exactly! I thought he should have been eating my rooster tail!
mod-it
Member
Above you said the power valves were set to 3.5mm spec...that's a typo right? You meant to say 2.5mm?
You shouldn't get smoked by a 600. What peak rpm are you pulling right now? Is it maintaining 8400-8500 rpm all the way through? In the right snow conditions the 600 with ripsaw may jump out on you off the line, but you should be reeling him back in at a fairly steady pace.
I think you have some clutching issues. At 8k miles some things are certainly getting wore out. Also clutching could've been changed by previous owner. Perhaps they haven't been cleaned in a long time...you wouldn't believe how much that makes a difference just in itself. I may be barking up the wrong tree and you have a lot of clutching experience, but above I see more talk about carbs than anything, so forgive me if you have a lot of knowledge and I'm out in right field. I think the most help could be offered by some of the clutching gurus here, such as MrViper. They are going to need some info:
1. Do you just want the stock components to work like they should? This will involve pulling the primary and secondary and inspecting for wear. At 8K miles it will be recommended to replace both springs, check roller wear in primary, check buttons in secondary, what wrap is secondary at, what does belt deflection look like?, and a good thorough cleaning. And we'll hope that gearing hasn't been changed.
2. Do you want a specific setup for your type of riding? Drag racing, corner to corner trail, etc. This will involve some different springs and different helix, possibly different arms for the primary and adjusting rivets. You're probably already going to be buying springs, for another $100-$150 you can pick up a helix and some primary arms (probably from this site's parts thread) and have something that will pull a lot nicer than the stock configuration.
Just clean clutches can make a world of difference. Years ago I bought a used 93 Exciter ll sx. I mistakenly assumed the dealer place that had taken it in trade would have gone through it and cleaned clutches, etc., so I just took it right out as is that weekend to ride. My riding buddy had a Phazer at the time, it was originally a 121 that he had put a 129 on and geared it down to pull the extra track. No other mods. My Exciter was very rich feeling in the mid range and even fouled a plug once. When we lined up to drag race and compare, he smoked me pretty hard off the line and then maintained 2 lengths on me through 500'. We both knew that shouldn't happen. That week I went through the Exciter, cleaned carbs and lowered needles a notch. Then went through the clutches which were very filthy...we're talking belt strands filthy. Cleaned it all up, no adjustments made. The next weekend when we lined up, it wasn't even close. That Exciter just flat walked away.
Mod-it, Yes, thank you, I meant 2.5mm. I think your right about the clutches and your not out of line at all, my understanding of clutches is very basic. I would love some suggestions for the correct weight and spring combination. In regards to my performance preference, low to midrange acceleration for the trails would be great. I don’t care too much about top speed, I just like to get there quick.
I bought the sled from a friend of mine that puts on between 3k-4K miles a year on sleds riding in Canada. He rode it for a couple years and kept it for a back up. It was sitting for quite a while, so the clutches most likely to be dirty. The sled is bone stock except the M-10 suspension that was put in when he bought it.
Thank you for your response. Any information would be appreciated. Thanks!
I bought the sled from a friend of mine that puts on between 3k-4K miles a year on sleds riding in Canada. He rode it for a couple years and kept it for a back up. It was sitting for quite a while, so the clutches most likely to be dirty. The sled is bone stock except the M-10 suspension that was put in when he bought it.
Thank you for your response. Any information would be appreciated. Thanks!
mod-it
Member
I had a SRX in my head, a stock Viper will be a closer race but you should still do better than you are. Do a search for a corner to corner trail set up, I think that'll be the setup you'll like. For starters I would just open up both clutches to look for wear and clean thoroughly. Knowing if you're sled is hitting and maintaining peak rpm (8400) is important.
You'll want to get a primary puller tool. You'll want to check for wear on the rollers, arms move freely, etc. You can also check if you have stock components or not. Primary your stock arms/weights are 8ek, 14.5mm rollers, Y-W-Y spring; secondary is red spring at 70 degrees, 47 degree helix.
In the secondary check that the wear buttons are in good shape. Note what wrap the secondary is set at. Also on the back of the secondary there are three bolts that the tips are designed to wear. They may or may not have washers on them, they come with them but can be removed to adjust belt deflection. The further in the screws go the farther apart the sheaves are held open and thus lower the belt in the secondary...so add washers to raise the belt height and remove to lower. Belt deflection is where the belt sits in the secondary, you want it about an 1/8" above the top of the sheaves. A search for this procedure can be found quickly using search function. If you can't get it set right, buy new bolts, the ends do reach a point that they have worn too much to get it set right. It is also surprising how much a worn belt will effect acceleration.
When cleaning clutches I like to run a green scotchbrite pad around in a circular motion on the sheave faces. As long as it doesn't weird your wife out, a dishwasher works good to run clutches through, otherwise just hot soapy water, the scotchbrite, and a toothbrush for the nooks and crannies. I put a very, very light coat of grease (just a bit on tip of my finger) on the bushing of the secondary that slides over the shaft, and leave everything else dry.
You'll want to get a primary puller tool. You'll want to check for wear on the rollers, arms move freely, etc. You can also check if you have stock components or not. Primary your stock arms/weights are 8ek, 14.5mm rollers, Y-W-Y spring; secondary is red spring at 70 degrees, 47 degree helix.
In the secondary check that the wear buttons are in good shape. Note what wrap the secondary is set at. Also on the back of the secondary there are three bolts that the tips are designed to wear. They may or may not have washers on them, they come with them but can be removed to adjust belt deflection. The further in the screws go the farther apart the sheaves are held open and thus lower the belt in the secondary...so add washers to raise the belt height and remove to lower. Belt deflection is where the belt sits in the secondary, you want it about an 1/8" above the top of the sheaves. A search for this procedure can be found quickly using search function. If you can't get it set right, buy new bolts, the ends do reach a point that they have worn too much to get it set right. It is also surprising how much a worn belt will effect acceleration.
When cleaning clutches I like to run a green scotchbrite pad around in a circular motion on the sheave faces. As long as it doesn't weird your wife out, a dishwasher works good to run clutches through, otherwise just hot soapy water, the scotchbrite, and a toothbrush for the nooks and crannies. I put a very, very light coat of grease (just a bit on tip of my finger) on the bushing of the secondary that slides over the shaft, and leave everything else dry.
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Thanks for the information and the proper spring, weights and roller setup. I plan on ripping this sled apart and doing some upgrades this summer. I had a riot with it over the winter and would love to realize its full potential. With that said, do you have a better configuration for the clutches that will help me gain some performance? Or do you think that the stock configuration is best? Also, do you see any value in buying a comet clutch and using their adjustable weights and such? I think I can get the whole clutch and setup for around $500.
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I just went and looked at the 8EKs. The finishing force on that profile is not good.
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mod-it
Member
Since I have a Mnt. Viper and mostly ride powder either boondocking or playing on hills, I haven't ever looked for or played around with a clutch setup for trail riding. But I know I have seen several different ones over the years posted here, from stock component changes that offer a nice improvement to Heavy Hitters or Heel Clickers.
Realize that a trail setup and a drag racing setup are different setups, you mentioned trail so that's what I'd search. Trail will accelerate hard but lack on the top end, maybe even lose some top end. Drag or lake will be setup for fastest top speed and getting to full shift out as quickly as possible. One stock parts setup I've seen several times is simply putting in a 51-43 Helix with everything else stock and setting it at 80 degrees. Another simple one was a 53-43 Helix with a green secondary spring. Both of these were recommended as a better accelerating option over stock. MrViper has a lot of Heel Clicker experience and highly recommends them, and has done a lot of clutching work overall. I'd bet my sled that his clutching recommendations will offer a solid improvement over stock.
The main thing is to really pay attention to what type of setup it is and make sure it is a trail setup. If I were trying to setup a corner to corner short track sled and was fully committed to that, then I'd also be looking for a bit lower gearing recommendation to go with a clutch setup as well. A corner to corner sled doesn't need a 100mph top end, so I'd be looking for gearing closer to an 80-85 mph top end. Then I'd search this site to find a highly recommended corner to corner clutch setup, most likely with either Yamaha clutch components or Heel Clickers since so many have experience with them here.
You did mention drag racing a buddy, so you may want something in between a trail and drag setup. A corner to corner setup will have you pulling your buddy out of the hole and through midrange, but then him reeling you in on the top end if there's enough room.
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A couple of bucks
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What is your % on & off trail. Stock track? Longest stretch where you ride? It sounds as if you are a corner to corner guy. Jack rabbit riding.
With your buddy having a 1.5" track and you still(probably) having a stock Yokohama .875, you will get smoked off the line.
A clean clutch & a good track go a looooooong ways.
With your buddy having a 1.5" track and you still(probably) having a stock Yokohama .875, you will get smoked off the line.
A clean clutch & a good track go a looooooong ways.
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journeyman
Active member
I tried a handful of aftermarket mufflers including the MBRP and an SLP on my Viper using my dad's Viper to test against. Seems every can for these the sled falls flat on it's face and feels really flat. Put the stock muffler back on an viola, I have power again. Needless to say they did not stay on mine. It was significantly slower with a can on. Not sure if the photos are on here anymore but I took some of a stock can cut open too. There are three separate hollow chambers inside as the exhaust twists around to each chamber before it's released. Between each chamber there was a perforated metal baffle. I was hoping to do some kind of mod to it but after looking it over there wasn't much I could do.