Numerous MCX-Nytro questions.

[Tuesday]

Nothing to serious but I have a few questions about dialing in the mcx-stage 1 kit.

Running stage 1-240 MCX dealer installed, headshim kit. Typically ride golden/revy 4000-8000ft, deep fluffy snow, warmer temps (-5 to -12c). Ez-ryde skid 162, fox floats, all new bearings, new chain, new bushings. Approaching 3300km.

Clutching-Shockwave with purple, 74g daltons with blue-white-blue.

Here are a few questions.

1. Lets start with clutching.

I have spent little time trying to dial it in because it runs so smooth but I have begun the task of trying to get it running perfect.

IRC shockwave was approx 2.5 turns out and at lower elevation it would spike to 8600, fall to 8100 then slowly climb to about 8450 on a long pull across a field. I did not have much time before this last trip so I turned it in 1/2 turn. I noticed at altitude approx 6.5k ft alt it would hit 8700 ish then hold around 8300. I cranked the shockwave all the way in and highest I saw was 8800 spike and occasionally it would hold 8400 at the most. During all the this testing was pulling 14-15 lbs boost.

I plan to buy one of the mcx display boxes so I can log all the data because at full boost and rpm you are going so fast its hard to get a good read.

Last year I never spent much time check rpms, it was 8kish and pulling hard so I dont have much of a baseline.

Wonder if I need new springs and maybe less weight in the primary? Or better yet crank up the boost hehe.

2. Water in oil

3 days of riding and I notice that my fresh engine oil has a slight water tinge to it. How does it get exposed to water?

3. Belt height in secondary

How high does the belt typically ride in the secondary. ie what are you aiming at keeping it at?

4. Breather tube off mcx oil reservoir

How much oil typically should come out of this with normal riding and no roll overs. I seem to get a bit out of this hose every time I ride.

5.Ez-ryde skid.

220lbs- 09 skid with shorter front shock. Any general set up tips? I have the damping set fairly hard and both shocks approx 1 inch preload.

Also the tunnel cooler was dripping melted water onto the rear shock reservoir and make a massive snow chunk on it. Is this normal for this skid on a stock tunnel?

6.

 

[Washy]

Clutching, you have too much primary weight. Run 1.5 to 2 (48-50 degrees) turns out on the shockwave with EPI purple spring. 2.5 turns out is way too much. You definately need to drop some weight out of the primary.

The oil tank is actually vented to atmosphere and is designed to breath in and out. So you will see the water in the oil alittle. Let it idle and get the oil hot and you will see water vapour coming out the vent.

Oil spilling out is normal if you are rolling it over. Check to make sure the drail on the bottom small oil tank that is connected to the top of the oil reservoir is clear. Connect a longer hose off the outlet of the MCX suppliled oil tank and run it to the bottom of the sled.

EZryde, the external reservoir will build up some snow. Especially if the rear cooler is dripping water on it. Just kick it off.

As for setup what is it not doing that you would like it to do better. Preloads seem right. If you dont want the dampening so high turn the rear spring up 1/2 inch more and reduce dampening or add another plastic shim inbetween the two rear springs.

 

[Tuesday]

Clutching, you have too much primary weight. Run 1.5 to 2 (48-50 degrees) turns out on the shockwave with EPI purple spring. 2.5 turns out is way too much. You definately need to drop some weight out of the primary.

The oil tank is actually vented to atmosphere and is designed to breath in and out. So you will see the water in the oil alittle. Let it idle and get the oil hot and you will see water vapour coming out the vent.

Oil spilling out is normal if you are rolling it over. Check to make sure the drail on the bottom small oil tank that is connected to the top of the oil reservoir is clear. Connect a longer hose off the outlet of the MCX suppliled oil tank and run it to the bottom of the sled.

EZryde, the external reservoir will build up some snow. Especially if the rear cooler is dripping water on it. Just kick it off.

As for setup what is it not doing that you would like it to do better. Preloads seem right. If you dont want the dampening so high turn the rear spring up 1/2 inch more and reduce dampening or add another plastic shim inbetween the two rear springs.

I think there is to much weight in the primary as well. The springs have also never been changed. So to start with I will throw in some new springs and a new belt and see where I am at. I am sure I will find that I have to much weight.

How much weight are you running washy? The loaded weights you run what is there actual weight? Buying weights can get expensive so I only want to do it once.

Also when the the shockwave is turned all the way in what degree of helix does it start at?

The hose off my mcx oil reservior is long and at the bottom with a small bottle on the end. It can breath as I drill some holes in the bottle but my theory is it would semi contain the oil in a roll over. It does have a tether installed as well. I was just surprised to see how much oil it collected with out rolling over though.

Suspension seemed fine, I did not get to test it on any super steep climbs but it did seem to couple decently. It was definitely smoother on the trailer then that POS stock skid. I too just kept kicking the snow off but man a few times there was a massive ice chunk on that reservoir. I will mess with it more once I start climbing. One thing I noticed is that it has way more preload/sag with nothing on it compared to my friends M 10. Which only increases when we would both stand on our sleds. I know sag is useful but you only need a few inches of sag. The m10 just appear to be more robust.

Later

 

[Washy]

8BU-00 fully loaded are 56.7 grams but the profile is really aggressive. 14.5mm rollers. The standard M10 is reobust but it weights 25-30 lbs more than the ezryde. The one M10 we had weighted more than the stock skid.
Shockwave starts at 42 degrees maxes out at 58 degrees. 1/4 turn is 1 degree.

If you want less sag, increase the rear spring tension. This will also alow you to run less compression dampening alittle.

 

[Tuesday]

56 grams! I am way out to lunch with 74's then? I need to pull things apart and see exactly whats going on.

The person I bought it from gave me the receipt with all the work ups and it says 74g daltons. Something seem fishy.

Maybe I will pull it apart this weekend.

 

[Washy]

Not necessarily true. The 74 could be close. The 8Bu's have a different profile than the daltons so the weights will be different. I assume your daltons are adjustable, I would try 70 grams if you can and see how it runs if you infact are running 74 grams right now.

Or go buy a set of 8Bu-00 and load them up with 2 steel rivets and be done with it.

 

[Sleds R Fun]

Dear Tuesday

Washey is correct. 8BU's fully loaded, 1 to 1.5 on the shockwave. Everthing else seems normal.
I bought the sister sled to yours. Mine also had 74 daltons. If I'm also correct you have a stage 2. Do you have a pump above your battery? If so get some Av Gas and turn the thing up to 17-18#.
Cheers

 

[Tuesday]

Washey is correct. 8BU's fully loaded, 1 to 1.5 on the shockwave. Everthing else seems normal.
I bought the sister sled to yours. Mine also had 74 daltons. If I'm also correct you have a stage 2. Do you have a pump above your battery? If so get some Av Gas and turn the thing up to 17-18#.
Cheers

Built at yamaha whitehorse? Are you still running the 74's or did you switch to the 8bu's?

Yes mine is the early kit and can be cranked up to 17 I just havent done it yet. The extra 30 hp may be enough to pull the 74. I am wondering if that is what they set the clutching for in the first place? I do have easy access to AV fuel as well.

I will tear things apart the next couple of days and see whats going on. The belt is sitting lower in the secondary (about 10 rides on it) and the springs have never been changed so they are due.

http://www.daltonindustries.com/products_yamaha_snowmobile.asp

Looks like some of their weights are adjustable. I need to take a look.

 

[Sleds R Fun]

Nitro Clutching

Yes Yukon and I did have the 74's. The 74's will work however the tension on the secondary will need to be quite high and I found it hard on belts.I am running the 8bu weights.
I would do what washy has mentioned, simply put: buy some 8bu's from yamaha and install the rivits to make them fully loaded at about 57G. Also get some small rollers from yamaha(forget the size). In the secondary get a green cat or purple EpI and run the spring tension at 2-0.// 1.5 turns out on the shockwave.
As for belt height check your owners manual and that will tell you how to adjust sheve height.

The best purchase you can possibly make is a turbo controller, there about 180 bucks and trust me its money well spent. The difference between 15 and 18 is night and day.

 

[Tuesday]

Yes Yukon and I did have the 74's. The 74's will work however the tension on the secondary will need to be quite high and I found it hard on belts.I am running the 8bu weights.
I would do what washy has mentioned, simply put: buy some 8bu's from yamaha and install the rivits to make them fully loaded at about 57G. Also get some small rollers from yamaha(forget the size). In the secondary get a green cat or purple EpI and run the spring tension at 2-0.// 1.5 turns out on the shockwave.
As for belt height check your owners manual and that will tell you how to adjust sheve height.

The best purchase you can possibly make is a turbo controller, there about 180 bucks and trust me its money well spent. The difference between 15 and 18 is night and day.

Sounds good where do I buy 8bu's? Are those yami weights? As for boost I could just adjust the waste gate. The mcx control lbox has worked well for me. Down lower it will pull the boost back 11-12 and up top I get full boost 14-15.

 

[Washy]

Give Steve at Slavelake yamaha a call. They will have the 8BU-00 wieghts and will know exactly what you want. Yes they are Yamaha weights. he will have the spring you need also. You can run 13-14 psi around home 2000 feet on premium.

 

[Tuesday]

I dont have my clutch puller here but will take a look. I did look inside at my primary weights and they do have rivets on them. Not to say they are adjustable but they "look" adjustable. Wont know for sure until I pull it.

Regardless I think I will freshen up the weights, rollers, springs just to take out any guess work.

 

[Sleds R Fun]

clutching

You can change the weights and springs without a puller. The Daltons you can add rivits to make 94's.
Yes you can adjust the waste gate to obtain a desired boost level, but that will grow old fast.
If you want to obtain a constant motor Rpm and boost levels for various conditions the compensator will never perform especially if you would like to run 15-18#. You will need to get a boost controller as RPM and boost go hand in hand.
cheers

 

[Tuesday]

Well I pulled it apart and it has 8bu's-00 in it. Looks like a silver rivet near the end (alum I assume) and a yellow near the bolt hole (brass?) Which rivets do I need to have in there.

Check the pics.

Purple spring is in the 1 position.

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[Tuesday]

I see the rollers . I took out the bolt that goes through the roller but the roller does not come out. Is there a trick to getting it to come out so I can measure it?

 

[Thistledoo]

Steel/steel is what we run....have to loosen that little allen head set screw (use the right size or you will strip it) and then a sleeve slides out.

 

[Washy]

Yep those are the 8BU-00. I run same as thistledoo. Steel/Steel. The brass should work. Your rollers should be very easy to get out. Seem odd that they are hard to get out. It could be that your rollers are seized, they should roll freely on the bolt. The rollers could be your problem.

 

[Tuesday]

So I have steel and brass? Is that less weight then? Are some of these rivets hollow and solid?

 

[Tuesday]

Yep those are the 8BU-00. I run same as thistledoo. Steel/Steel. The brass should work. Your rollers should be very easy to get out. Seem odd that they are hard to get out. It could be that your rollers are seized, they should roll freely on the bolt. The rollers could be your problem.

I took out the bolt in middle of the roller and the rollers are spinning freely and have smooth edges.

Found the set screws on the rollers but all 3 that are closer to the tunnel are so tight that I was afraid to strip or break the wrench. All 3 towards the front end cracked loose though. Maybe the rear ones need some heat.

So in the end I have the same set ups I wonder if my springs just need to be replaced?

I did replace the skid this summer but I cant imagine its generating a bunch of resistance to mess up rpms.

New bearings and chain as well. I double check the chain tension and looks good.

Track is actually fairly loose. The new 09 ez ryde skid with extroverts did not ratchet on me and it is again set loose. On the stand you can turn the track easy by hand.

shrug........

 

[Washy]

Well sh*t. Atleast you know what you got now. The springs very well could need replacing. I replace mine every 1500k. 4500 kms on sled now.