mutley531
Veteran
I have an '07 Apex with several lightweight goodies on it (Timbersled front/rear & drop brackets, Floats, Excell undertunnel exhaust, Boss seat to be installed, no rack on back, Hartman bumper, no radiator). Overall I am extremely pleased with the machine, but I am not pulling correct RPM at altitude. I ride mostly around 10,000 ft and when making a climb my rpms are usually just at 10,000 sometimes down to 9,700. I am sure if I can get the rpms up to 10,500 I will get more power out of it. The engine, clutching, and gearing are all stock. Any ideas on how to get the proper engine speed at this elevation? I have been told to try a Cat yellow secondary spring. Has anyone tried that setup? I may just give Tom Hartman a call and order a kit from him, but that will likely be for next year. Also, the sled only has 300 miles on it. I was told these engines start to wake up at around 500 miles. If that is the case I can just continue to ride it until then and re-evaluate it then. Any help would be greatly appreciated.
2XM3
Extreme
Slap a 19 top gear on that baby, you will love it. Best 30 bucks you ever spent, really easy to do. Or go 19/42 with a 70 link chain.
OR, take some weight out of the primary. Remember though if you set it to 10500 in a climb, you will most likely hit the rev limiter on hardpack.
I set mine to just barely kiss the rev limiter on hard pack and she climbs at around 10300-10400, less in powder. Don't jack with the secondary to set rpm.
OR, take some weight out of the primary. Remember though if you set it to 10500 in a climb, you will most likely hit the rev limiter on hardpack.
I set mine to just barely kiss the rev limiter on hard pack and she climbs at around 10300-10400, less in powder. Don't jack with the secondary to set rpm.
mutley531
Veteran
Thanks for the reply. Are any clutching changes required with a change in gearing?
2XM3
Extreme
I would swap gears first, go with the 19/42 with 70 link chain if you ride a lot of boondocking and mountains, I run 18/43. Leave the clutching alone and see how the rpm does with the new gear, you can try blue-silver -blue primary spring if you like a higher enguagement.
I would also reccomend the shockwave helix, easy to ajust for the fine tuning, they work really good.
Oh, as said 100's of times get the camo extreme track.
I would also reccomend the shockwave helix, easy to ajust for the fine tuning, they work really good.
Oh, as said 100's of times get the camo extreme track.
Jabber
Extreme
- Joined
- Dec 24, 2005
- Messages
- 120
- Location
- Penticton B.C.
- Country
- Canada
- Snowmobile
- 2017 Sidewinder mtn 162
I nun a19/42 gear setup on my sled now. My rpm was always around 9500 in the steep and deep. Now its 10600 with track speed at 48mph. at 7500ft elevation. I love the gearing for boondocking and hill climbs.
2XM3
Extreme
Now give the 18 a try.........can't go wrong
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