Gearing change

[justforfun]

I have ridden a couple of seasons with a Nytro 153"track and extrovert drivers on my Phazer. I tried the 3" setback and drop 1". then tried stock mounting with rail extensions. Overall, not much difference between the two. The front mounting is a bit easier sidehilling, and the setback is better on the trail. I got a second project Phazer which had a 4" setback which is terrible, so I will run one 3" and one extension this year and try them back to back. I run the track looser which frees up some power, but the bigger track and slightly higher gearing from the bigger drivers is noticeable in the steep and deep or wet snow. I want to try a 45tooth lower gear to see if I can get my track spin back. The MP has a 19/45 with 82 chain. Mtx is 17/41 with 80 chain. It looks like there is some play room with the 80 chain and might just work on a 17/45. An 82 could be too long. Has anyone done this?

 

[Snowmixer]

I know I've read about a few people on here using the 17/45 combination, though I can't remember their thoughts/success with it. As for the chain, the 80 does seem to have a lot of excess, but unfortunately not enough to run the 17/45. I am planning on trying the 17/45 combination this season so I mocked up the 80 link chain with both the 41- and 45-tooth gears to see if it would work. Although it's very close, I could not get the chain with both gears on it to slide onto both the drive (track) shaft and jackshaft.

 

[justforfun]

I found a thread where someone got this to fit , but had to remove material from the back of the adjuster. perhaps it was a well used chain.

 

[Snowmixer]

Well, I can say that it was VERY close to fitting. A few taps with a rubber hammer may have moved things enough for the gears to slide on, but I didn't want to force it. My chain has about 750 miles (about 1200km) on it, so maybe it's not too stretched out yet. I'm thinking that if someone had a slightly more stretched chain and removed the thin piece from the back of the adjuster, it would be a nice snug fit. Whether or not it would be a good idea is another question altogether, unfortunately not one I know enough about to be able to offer much meaningful input at this time. It does seem odd to me that there is so much slack on the 80 link chain with the 17/41 combination, I would think the extra wrap/unwrap of the chain on the bottom gear when moving would be enough to rob some power, though maybe not enough to notice.

 

[justforfun]

I agree there seems to be more wrap than usual on the stock setup. I have 4000 km plus a spare well used chain, so will try that once I get a gear.
Where did you get the 45 tooth?

 

[Snowmixer]

My guess is that the extra wrap is a result of nothing more than Yamaha trying to use one chain for as many applications as possible. I bought my 45 tooth gear from Yamaha Sports Plaza a while back, but it may be worth contacting UP bushman on here, as I think he may still have one available from his MTX that he's parting out. Here's a link to that thread: http://www.ty4stroke.com/threads/f-s-phazer-mtx-getting-parted-out.128492/

Yamaha Sports Plaza (#34 on the schematic) http://www.yamahasportsplaza.com/oemparts/a/yam/5003c36af8700212fc841f9f/track-drive-2