Apex Mcx

[offside]

Need some help with my Yamaha apex year 2007 with MCX 290hk kit. I live in North Sweden. I have updated a lot on my snowmobile and changed all bearings, TrackPoint, ne-abrasive and fixed all dampers and configu bogie for my weight. My setup.

Primary: Supertip 60g, inner hole 6g. middle 14g and tip 3g. Stock rollers 14.5 and yellow, silver, yellow primary spring.

Secundary: Dalton helix 54/48, Yamaha, white spring, 2-6 = 80 degras

Bombarider track 41mm, 345 cm long and 9 Tooth noslip

22 top gear, 38 lower and 68 chain

Top rate 10 900 rpm (1.1 bar). Engagement, I do not know.

Fuel: 98 octane and tripack octane booster.

My problem is that it wants to go in rev limither from full-throttle start. When I run on trails. When I'm off the trail, sometimes. Are gun happy besides. The spring in the primary is new and secondary are used. Picked it apart tonight and could see that it was the belt
residues at the bottom of the secondary. I'll buy a new spring in the secondary and it is leaning towards Yamaha white. I'm very close to being happy and thought in case anyone could help me.

Thanks in advance / Tobias[/img]

 

[ROCKRTX]

Probably The white spring at 6-2 is coil binding and is holding your secondary from shifting and make your belt slip,try 3-3 setting.

With 22-38 you will run out of gear at 115 Mph and hit the rev limiter fast.unless its a mountain sled i could suggest 25-38 gearing for a 290hp turbo.

 

[Turk]

You need way more inner weight in your supertips. You want to start heaviest in the inner most hole & gradually getting lighter towards the tip.

 

[offside]

You need way more inner weight in your supertips. You want to start heaviest in the inner most hole & gradually getting lighter towards the tip.

Thanks for the reply. As I understand this so if you have a mountin model then you should have most weight in the inner hole. My snowmobile is 345cm tall. If I put the most weight in the inner hole, will not I get more problems when boost come and rev limither? How do I do with the secondary. Stiffer springs and lower degree?

 

[shawnmcgr]

You need way more inner weight in your supertips. You want to start heaviest in the inner most hole & gradually getting lighter towards the tip.

Thanks for the reply. As I understand this so if you have a mountin model then you should have most weight in the inner hole. My snowmobile is 345cm tall. If I put the most weight in the inner hole, will not I get more problems when boost come and rev limither? How do I do with the secondary. Stiffer springs and lower degree?

I don't think you've got an APex Mtn with a 136" track (345cm/2.54cm/in). But I think what Turk is getting at is you need a little more weght early on to get the primary shift ahead of your HP/torque. I would think slightly more weight over all.

 

[offside]

You need way more inner weight in your supertips. You want to start heaviest in the inner most hole & gradually getting lighter towards the tip.

Thanks for the reply. As I understand this so if you have a mountin model then you should have most weight in the inner hole. My snowmobile is 345cm tall. If I put the most weight in the inner hole, will not I get more problems when boost come and rev limither? How do I do with the secondary. Stiffer springs and lower degree?

I don't think you've got an APex Mtn with a 136" track (345cm/2.54cm/in). But I think what Turk is getting at is you need a little more weght early on to get the primary shift ahead of your HP/torque. I would think slightly more weight over all.

My sled.

 

[shawnmcgr]

Yes, that's what I thought you had. Must be fast as hell with 290hp! So I would think you could throw a lot of gear at it to get max top speed, if that's what your looking for.