My 900 vs 2006 Yamaha Apex

[IF900RMK]

Ok so each year I go down to bear lake and ride with my brother in law who has a 2006 yamaha apex. His sled is bone stock. Two years ago when we rode together we would race each other up a pretty steep 500' climb, I only had my can on mine and even though his sled is a 1000CC we were neck and neck all the way up every time, also probably cause his sled is about 100-150 lbs heavier. Last year same situation, then this year I did most everything in my sig with the main things being gearing down and having SLP balance my clutch and install a team helix. So I just got back from a weekend down there and this time on the same race/climb I killed him on the hole shot and by 1/4 way up the mountain I had him by about a sled and a half, by the middle he was gaining and by 3/4 we were neck and neck and then by the top he beat my by about a sled length. What do you guys think I think I don't have something right with the new gearing, weights, or helix. Out of the hole is intense but I only get about 40-45 mph track speed while climbing and I don't notice a difference between 3/4 and full throttle. So does this sound right or is something off. Thanks guys

 

[Danbot]

There is nothing in your sig. What gearing / clutching changes did you make for this year, since you are comparing to your last years matches against the apex.

 

[IF900RMK]

What the heck happened to my sig!! Man I need to upgrade. My sled is a 2005 900 159 I geared it to 19/42, If I remember right when SLP balanced the clutch they put in a blue/pink spring and I had them put in the #720419 helix.

 

[IF900RMK]

It seemed over the weekend that most of the time climbing I had to be pinned, maybe thats just the way it is with the new gearing, but I want to be sure I don't have something setup wrong.

 

[Danbot]

It seemed over the weekend that most of the time climbing I had to be pinned, maybe thats just the way it is with the new gearing, but I want to be sure I don't have something setup wrong.

Hard to say if anything is actually wrong, but the first thing I would do is black marker some lines on your clutch sheaves and run it to see if the clutches are fully shifting out. I would assume your operating rpm is good because you didn't mention it. 19/42 should be enough legs for any normal climbing

 

[Danbot]

Oh and when I switched to 19/42 this year I found almost the opposite as what you are describing. I can play with the throttle when climbing, engine power is getting to the snow much more efficiently and I always have some throttle left.

 

[IF900RMK]

Ya the belt is marking all the way out on the clutch, in fact it is making a dark black mark about an inch from the outside edge of the clutch. Disco what size weights are you running?

 

[Danbot]

Ya the belt is marking all the way out on the clutch, in fact it is making a dark black mark about an inch from the outside edge of the clutch. Disco what size weights are you running?

for home: 4000 - 5000 feet
19/42 gearing
team 10-68's
SLP blue/pink spring
420409 team helix 64-40ER.46/64-44ER .46 in the second track
team red/pink spring 140-260 with delrin washers
This gives me about 7650 rpm and top speed of about 72mph

When I go to the big mountains (6000 - 8000 feet) I drop to team 10-66's to maintain my 7600 rpm

 

[Danbot]

IF900RMK which clutch is it leaving the black mark on? this could be an issue to look into.

 

[chunkysoup]

IF900RMK which clutch is it leaving the black mark on? this could be an issue to look into.

X2! there shouldnt be a black mark on ur clutches unless it is slipping. i would recommend a heavier weight or a lighter final rate spring in ur primary. I assume its marking the primary?

 

[94fordguy]

Ya the belt is marking all the way out on the clutch, in fact it is making a dark black mark about an inch from the outside edge of the clutch. Disco what size weights are you running?

X2! there shouldnt be a black mark on ur clutches unless it is slipping. i would recommend a heavier weight or a lighter final rate spring in ur primary. I assume its marking the primary?

You've definitely got some SERIOUS slipping issues to be leaving any marks at all on your clutch... I think Chunkysoup has some good advice here, you need to do some tinkering to get back to utilizing the full range of the clutch, and a lighter finish rate will allow you more travel up the sheaves. Once you confirm your getting full shift out on your clutch with the marker trick that Dan mentioned, you may have to change your weights to get your RPM back to where it should be (7400 range is ideal).

 

[Aussie Niko]

Just don't tell you mate that a few mods on the apex and it will be way faster than the 900.

 

[IF900RMK]

My rpms seem to be right on the dot at 7400 right now, but I am getting a black mark on the primary, I will see if I can get a pic posted tomorrow. Do I need heavier weights, I have 10-70's on there right now, or should I start with the spring?

 

[Danbot]

I think you have some spring work to do first, what spring is in the secondary?

Actually, the first thing I would do is re-inspect the clutches, and make sure they are physically capable of fully shifting. You say SLP just did some work on your clutch so a bad bushing seems unlikely, but you never know.

 

[Jmanwillis]

Do you have any other slp stuff on it? or is it stock? I run at bear lake tony grove running 70 MTX'S Mine will hold 7950 to 7900 I think your cluching is off for that altitude or like the others said your belt was slipping or not shifting out. Gearing is good, that is what im running. Next time i would ask SLP for there opnion on cluching for that elevation.

 

[IF900RMK]

Do you have any other slp stuff on it? or is it stock? I run at bear lake tony grove running 70 MTX'S Mine will hold 7950 to 7900 I think your cluching is off for that altitude or like the others said your belt was slipping or not shifting out. Gearing is good, that is what im running. Next time i would ask SLP for there opnion on cluching for that elevation.

No other SLP stuff besides the skis, I have an MBRP can and a fire n ice intake. I took my primary and secondary clutch in and had them balanced, the primary was a ways off, they put a new blue/pink spring in if I remember right and then they replaced the spring in the secondary with the same just new, red and black if I remember right. Then I had them put the team helix in. I tried to get some clutching recommendations from them but the really didn't say except the blue/pink spring I normally ride about 7-10,000 feet and I am not sure what the elevation for the bear lake area was. Anyway I am way happy with how hard the sled gets out of the hole, it just seems like I am not getting the rest out of it. I will get the pic up of the primary ASAP.

 

[Jmanwillis]

Bear lake area towards logan is in the 7 to 10 range im running SLP head pipe can and boondocker box so that is why your rpm's are lower. I'm not sure then on the clutching. you might go back to the stock cluching and race him again and see what it does and see what your Rpm's are. What belt are you running?

 

[IF900RMK]

I am running the 1115. Last year with stock gearing and clutching my rpms were around 7500 most the time if I remember right, I would also hit the rev limiter from time to time which I don't now. Do I need more RPMs or is 7400 about right for what I have on my sled?

 

[94fordguy]

I am running the 1115. Last year with stock gearing and clutching my rpms were around 7500 most the time if I remember right, I would also hit the rev limiter from time to time which I don't now. Do I need more RPMs or is 7400 about right for what I have on my sled?

7400 RPM is the peak torque spot for the 900 motor, so anywhere right in or just above that range is perfect.

I haven't done a whole lot of climbing with my sled this year due to the crummy snow conditions, but I seem to be pulling about 7500 on the good climbs and it pulls nicely at that. Just as a reference, my clutching is BONE STOCK and it pulls great; Black/green primary spring, 10-70 weights, and stock helix in the secondary nothing special, but it seems to work great for me.

As to the Rev Limiter, I am not sure exactly when it kicks in, but I believe it is pretty high, Max recall on my gauge has shown 7850 RPM and I have never hit a limiter.

 

[Danbot]

I think the rev limiter is 8050, although my max rpm shows 12,000! lol