Another gearing question & other issues....please advise

[phatmatt]

Long story short, I asked my local dealer to drop a gear on my 2011 Nytro MTX 153 (without realizing that I already had an 18 tooth top gear and in reality probably shouldn't go any smaller). Instead, he upped the gear to a 20 tooth, which kinda pisses me off as it's the exact opposite of what I requested. Anyways, I haven't had the sled out yet and don't want to in case I want to take it back to the dealer for a refund/changing back to 18. My questions are as follows:

1. Is a 20 tooth top gear going to hurt my performance at all? I'm thinking especially with regards to the deep snow (I'm not a mountain rider but I am fortunate enough to live in an area where 2-3 feet of powder is fairly common. Will a 20 be too high to lift me on top of the powder when I squeeze the fun lever?

2. With the 18 I was maxing out around 145 km/hr or so......what should I expect with the 20? Will I notice a significant drop off in my bottom end power? Top speed is not really important to me as I rarely ever go past 140 km/hr or so.

3. Does anyone know of any relatively cheap mods to boost the power (especially the low end) of my sled? There's no way I have enough $ for a turbo (though it would be sweet).


By the way, I drive between sea level and 2500 feet for basically all of my riding and only make it to the mountains once every couple of years or so. I weigh 190 lbs and rarely carry any extra weight with me (gas, backpack, etc.)


ALSO, unrelated to the situation above I have a couple more questions for us Yammie faithful....(I've never ridden anything other than Yamaha and have always loved them, especially for their reliability, however, I'm starting to rethink this for the reasons below):

4. Does every Nytro reverse gear suck as bad as mine? Any suggestions for improving the operation of this terrible contraption?
5. Does anyone else have major trouble with slider wear? After 3500 km I am now on my 3rd set (never had a problem with this until I switched to my Nytro.....have had old VMax's, XTC's, SXR's, SRX's, Vipers but only the Nytro causes me trouble here).
6. Has anyone else had their bellypan fall right off? My belt was slipping like crazy at the start of the year so I looked underneath and noticed the entire things was GONE!

 

[bholmlate]

phatmatt

1. 20/40 gearing was the stock mountain gearing on the '08 MTX. So 20T is not all that uncommon. From 18T to 20T you will see a slight change in performance but these nytro's have so much torque down low you may or may not notice a whole lot of difference. However with a 20T you may have problems holding RPM in really deep heavy snow. People seem to like a 19T top gear as well. I was told that it only really saves wear on the belt a little if you gear them down so i still run a 20T gear with a 163 Powerclaw track and it seems to work well for me. I dont ride in 3 ft of fresh all the time though

2. you will pick up a little top end speed but it is tough to say how much because it depends on the type of snow you are riding in. a couple of km/h at the most

3. Cheapest mod is an exhaust system but you are still talking +$500. I would be careful of any air box mods because some of them are known to loose power rather then gain any.

4. Yes the reverse linkage is sometimes a pain. i have heard if you lube the linkage sometimes helps make it easier to slide into reverse.

5. yes the Nytro being a heavy sled wears out Hyfax''s prety quick usually right up front where the rails turn up with the OEM skid. Yamaha skid wheels are too small as well. I think Allen with Ulmer Racing has a low snow wheel kit that helps but most people have thrown away the OEM skid for an aftermarket one that are easer on Hyfax's

6. Belly pan falling off is a new one for me. Most people opt for getting rid of the stock belly pan and go with an aftermarket one. Mountain Tech has one that gives you way more protection and the fit and finish is top notch.

 

[hugger70mtnmax]

My 153 came stock with 20t top gear. I didn't mind it till I switched to the 162.

Exhaust is the best way to power. I ran mine last year with the intake filter kit also and had to ride it once this year with the stock air box back on and I didn't notice any of the extra power I had last year gone.

 

[akvector]

I would suspect that gearing should be fine that is what I have and do not think that I need to gear down.

Power increase full and exhaust and k&n with PcV gets my vote. Better clutch set up would not hurt either.

I had some problems last year with my reverse popping out but no problems this year and I did not do anything to the adjustment. I think I had snow/ice build up.

Mountain tech for skid plate definately!!

Get some scratchers!!! I like slide kicks

 

[phatmatt]

Thank you for the quick responses.....keep em' coming.


I think at this point I might keep the 20T and see how it works.....I've done a little bit of research online and it seems like people are happy with 18s, 19s, or 20s so maybe a 20 will work fine for me and the next time I take a trip to the mountains I'll probably put the 18 back in.

 

[Dimebag]

Adjust the slack in the reverse linkage. It should not be any slack.
Remember one of the adjusting nuts is links.

Also use lithium spray grease on the spring and reverse mechanism.

Never had any problem to engage reverse after i did this.

 

[nitris223]

Tried both top gears. KM/h won't change much. Here is my set up for a 162 with Hindle exhaust. Weights loaded with 17.2 steel rivets in 2 holes and rivet with hole in the tip. 18 tooth gear, OPO primary, 14.5 rollers, stock secondary spring , 43* helix. Hurricane airbox mod, PCV and autotune. Pulls 9050 rpm. Put in the 20 tooth and it will only pull 8800 rpm.

Wife's sled is a stock 153 MTX with a Super-Q pipe. OPO primary, 14.5 rollers, stock secondary spring and 45* helix. Stock weights empty. 18 tooth gear bounces off the rev limiter by 75 mph. 20 tooth gear and it will run 8900 to 9000 on the trail and haven't checked it off trail. Wife doesn't complain so it must be fine for her. Putting the 20 tooth back in her's and I will check it this weekend for off trail performance.

I ran mine with the 20 tooth in some pretty good fresh snow and I think it ran good, don't recall loosing to much RPM's but then again at WOT across a field I rarely look at the speedo. To busy hanging on.

 

[nitris223]

Well it looks like I have to put some rivets in the 153. Still hitting the rev limiter. 20 tooth top gear droped the RPM down 200. Still hitting 9300 RPM. Now just to figure out which and where to put the rivets.