Gearing down an INdy Lite

[cateye5312]

I bought two 1999 Indy Lite 340's and I am in the process of long tracking them. I put a 133.5 x 1.5 track on one and am in the process of putting a 136x 1.25 track on the other. I also put X10 rear suspension brackets on and moved the front suspension bolt hole down an inch as well as 11 inch tunnel extensions. They look like mini RMK's now!

The stock gears are 17/41. The lowest gear I can get for the top gear is a 16T and the bottom gear appears to be the biggest one that can possibly fit in the case.

Ideas? Is it worth it ($35 each) to drop one tooth? Is there something else I can do? I am concerned about bottom end performance/ burning belts, etc.

By the way, I put Gripper skis (stock Poo mountain skis for the last several years) on both machines. It knocked 14 LBS off! I couldn't believe how heavy the old steel skis were!

 

[volcano buster]

I put a 136 x 1.25" under my '94 and geared it to 16:39 with a 64 pitch chain.

Your 17:41 is virtually the same gearing. Mine had no problem with me and the kid out in knee deep snow tractoring around. Combined weight was over 300# so I was grinning from ear to ear on that sled.

Post pictures when you can.

 

[cateye5312]

I went ahead and dropped the 16T gears in. Haven't had a chance to get them out test riding yet but just getting them in and out of the shop, on and off the trailer, etc. they don't have that low end bog/hesitation they had before so I think it was a good move. I have them at a buddy's place right now cleaning the carbs - I always fail at that job! Both sleds are now virtually complete so when I get them home I'll take some pictures and post them up. I'm excited to get them out on the snow! I think the boys are really going to love them! I want to chop the windshield/ add a mountain bar to one of them - the other one someone had already done and it made the sled look really good.

Oh and I gotta buy a flippin' battery! Gettin' kinda tired of doing that this year - seems almost every battery I own went bad this year.

 

[Buzz1y]

Hey, I know this is a fairly old thread but I am looking for a 16t gear for my 1999 indy 340. Do you remember where you got yours from? I can't seem to find one.

 

[volcano buster]

Hey, I know this is a fairly old thread but I am looking for a 16t gear for my 1999 indy 340. Do you remember where you got yours from? I can't seem to find one.

What do you have in it now?

 

[Buzz1y]

What do you have in it now?

It comes with a 17 on top and a 41 on the bottom. The older ones come with a 16 on top and 39 on the bottom but the 16 in the old ones only have 13 splines and I need for a 15 spline shaft.

 

[volcano buster]

Is there room for a larger gear on the bottom? Been too long since I did mine.

 

[Buzz1y]

Is there room for a larger gear on the bottom? Been too long since I did mine.

It doesn't look like there is any room at all for a larger bottom. I thought about measuring the shaft length from an old one and using it but the old top sprocket is also narrower so I'd be running a wider chain than sprocket.

 

[volcano buster]

It doesn't look like there is any room at all for a larger bottom. I thought about measuring the shaft length from an old one and using it but the old top sprocket is also narrower so I'd be running a wider chain than sprocket.

I think that is what I had to do. Picked up a smaller gear from my local AC dealer and he said the wider chain won't hurt a thing.

 

[Buzz1y]

I think that is what I had to do. Picked up a smaller gear from my local AC dealer and he said the wider chain won't hurt a thing.

I kind of thought it would be ok because it's not a 120hp machine lol.

I think that is what I had to do. Picked up a smaller gear from my local AC dealer and he said the wider chain won't hurt a thing.

 

[volcano buster]

Found my sheet:
Top gear: 16
Bottom gear: 39
Chain: 64
Drivers: 9 tooth
That setup pulled the 136-15-1.25" track real well.

 

[Buzz1y]

Found my sheet:
Top gear: 16
Bottom gear: 39
Chain: 64
Drivers: 9 tooth
That setup pulled the 136-15-1.25" track real well.

I believe that was factory gearing for those years on indy lites... its pretty kuch the same as my 17-41 set up thays why I wanted to go 16-41 to slow it down on the trapping trails. It seems to fuel up really bad if I cant get to a slough to open it up for a bit. Thanks for digging that up for me to look at.

 

[volcano buster]

Hmmm, if that was factory, I'm pretty sure I geared it down, maybe I didn't update my spec sheet like I thought I had.

I do show that I geared my 440 SKS down when I put the 133 x 1.5" on it.

 

[Jeff Schmitz]

Hmmm, if that was factory, I'm pretty sure I geared it down, maybe I didn't update my spec sheet like I thought I had.

I do show that I geared my 440 SKS down when I put the 133 x 1.5" on it.

The older 340 Indy Lites came with 16/39 gears as best I know, the '99 went to 17/41. A really good resource for finding out these things is at this Polaris link

Polaris Assemblies

It is a very powerful research tool, the SNO segment is usually the area you want to look at. Takes some learning to use is but has a huge amount of info. There is "hidden" info to be had on the parts/IPC listings, slowly run the pointer across the right vertical line and when it changes to a moveable indicator, pull the box open further to reveal more data, Usage is a good feature as it shows a limited, single page of whererver that part was used in the Polaris empire. If you really want to drill down and find where it was used, copy the part number, go to the Advanced tab and paste it in the box then just hit search. Don't bother with selecting the SNO segment. Now all the applications will be listed, not just a single page. Sometimes Polaris used the same part in, literally, a thousand different models. Enjoy!

 

[Jeff Schmitz]

I believe that was factory gearing for those years on indy lites... its pretty kuch the same as my 17-41 set up thays why I wanted to go 16-41 to slow it down on the trapping trails. It seems to fuel up really bad if I cant get to a slough to open it up for a bit. Thanks for digging that up for me to look at.

If you're having fouling problems at low speeds you might want to go through the carbs. May just be adjustment of the idle mixture screw. At low speeds the slide needle is not really in play. Now these Mikunis were notorious for having bad needle/seat sets from the factory. Mine were so bad I moved the fuel shut off from the stock location to the upper left inside cowl so I could shut it off going down the trail when it would start overflowing the carbs. Once I retired I tore into those carbs and found out just how nasty the needle/seats were. There is a pretty simple factory manual test - turn the carb upside down, put 4 psi of air to the fuel line. It should hold that 4 psi for a long time, good ones will hold 9 psi. Once I replaced the needle/seats with new, good ones the sleds were totally different machines. I pulled the electric starter/battery off one as it starts so easily and reliably. Polaris P/Ns for the needle seat are:

3130016 (old number) (used in some 600 Polaris machines) Note: The Polaris parts are pretty spendy, I hunt them down in the aftermarket sources like Dennis Kirk, about a third of the Poo Price!
3131146 Superseding part number, used in another 200 models!

Mikuni VM26/26- Needle and Seat Size 1.5 - VM26/26-1.5 Snowmobile - Dennis Kirk

Find the Mikuni VM26/26- Needle and Seat Size 1.5 - VM26/26-1.5 at Dennis Kirk. Shop our complete selection of Snowmobile parts and accessories including the Mikuni VM26/26- Needle and Seat Size 1.5 - VM26/26-1.5.

www.denniskirk.com

The factory manual for these Lites can be had for free, it is Vol III and covers '96,'97 and '98 Polaris sleds.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiaoIPSzfr1AhV7J0QIHT7EAX4QFnoECDIQAQ&url=https%3A%2F%2Fwww.snowmobilefanatics.com%2Fforums%2Fattachments%2F183232-96-97-98-polaris-service-manual-2010115205157875_20315.pdf&usg=AOvVaw06pksgfGXosS7jUXj0Y3xg

 

[Jeff Schmitz]

There is yet another way to "gear down" the Indy Lite series sleds - change the track drivers from the stock 9 tooth to an 8 or even 7. A number of side effects also result. Changing drivers is a bit of a drastic process that is a bit spendy when considering the price of new track drivers, pressing the old ones off/new ones on to the drive shaft and the time/effort to drop the suspension, open the chaincase, etc for the job. Track tensioning issues can show up as quite a lot of slack is created with the much smaller diameter 7 or 8 tooth drivers. With a 7 tooth the speedo cal goes completely out the window. Top end on the speedo is around 70 but actual sled speed per GPS is 47! I've had to go to 7 tooth drivers for a 1.5 paddle track for tunnel clearance, cargo pulling is improved a lot as a side bennie. 133 inch tracks in any bigger paddle configuration, ie 1.25, 1.5 are rare but there are a lot of 136's still around in 1.25 - 1.75 so that is what I up track my Indy's with. FWIW, while I have seen a few Indy's up tracked to 1.75 I have doubts as to the useful results where it counts, in fact I've seen engine power limits show up with 1.5's in deep snow, 40 indicated was tops across a lake. With the lower gearing though I've pulled 800 lbs down a reasonably flat trail.

 

[Jeff Schmitz]

There is yet another way to "gear down" the Indy Lite series sleds - change the track drivers from the stock 9 tooth to an 8 or even 7. A number of side effects also result. Changing drivers is a bit of a drastic process that is a bit spendy when considering the price of new track drivers, pressing the old ones off/new ones on to the drive shaft and the time/effort to drop the suspension, open the chaincase, etc for the job. Track tensioning issues can show up as quite a lot of slack is created with the much smaller diameter 7 or 8 tooth drivers. With a 7 tooth the speedo cal goes completely out the window. Top end on the speedo is around 70 but actual sled speed per GPS is 47! I've had to go to 7 tooth drivers for a 1.5 paddle track for tunnel clearance, cargo pulling is improved a lot as a side bennie. 133 inch tracks in any bigger paddle configuration, ie 1.25, 1.5 are rare but there are a lot of 136's still around in 1.25 - 1.75 so that is what I up track my Indy's with. FWIW, while I have seen a few Indy's up tracked to 1.75 I have doubts as to the useful results where it counts, in fact I've seen engine power limits show up with 1.5's in deep snow, 40 indicated was tops across a lake. With the lower gearing though I've pulled 800 lbs down a reasonably flat trail.

Update to the 7 tooth Track Driver Mod: When I did the first machine track upgrade it was to a 1.25 lug, there was enough clearance to keep the 9 tooth stock track driver. Results were really great, the sled was now far more confident and competent in deeper snow. There was a slight rumble sometimes that was hard to pin down and it seemed to be on the right side of the tunnel. No side rub I could see at all nor indications of track edge abrasion. I've since done a couple with 1.5 lugs and went to the 7 tooth drivers. 8 tooth might clear but considering the time and expense it wasn't worth the gamble. Besides, I liked the better pulling capacity and acceleration of the 7's. Got this sled into really deep challenging snow for the first time and was getting the "rumble" only a lot worse under full throttle. Had also noticed the "top speed" was now 80 indicated on hard pack and a flat lake, up from "70". Long story short, it was track tension. I'd set it to factory after the conversion but the track had stretched some over the couple years and loosened up. Not a lot and the "rumble" did not show up on hard pack at all but the combo of a looser track and a boat load of loose snow in the tunnel would provoke ratcheting! Didn't think you could get that with a 340 but there it is. Tightened both machines up to factory and no rumble from either. Go figure!