Gearing a Mountain Cat with drive/reverse dropcase

[JohanL]

Hello.

I have a MC800 EFI 151" -02 with reverse. This one was stock equipped with 23/40 gears. Lake racer wannabe ?

It has been running a 21/40 combo for some time and it's OK. Could it be even better? Thinking of numbers like 20/40 to 19/43 range...
I use it mainly at low altitude and sadly some trail riding, mostly getting to the good stuff. I do not intend to have a extreme high alt/ hillclimb gearing.

I checked all kinds of MC 800, KC900 ratios used stock, to get an overview what combination's would work with reverse. That was my assumption... 19/43 is a commonly used stock gearing with reverse.

Since reverse idler and large reverse lower gears are fairly expensive and not found i you average parts bin. I was going for the "best choice" with only a top gear and chain replacement. I went with the -03 MC 800 EFI w.reverse stock combination of 19 top, 22 idler, 40 lower and 70p chain. I was not able to fit this combo with a satisfactory result. A 72p chain is to long (it should be),and a worn (longer) 70p chain barely fits. Yielding more chain tension then needed, without using the chain backing bracket. I don't think i could have fitted a new 70p chain.
Is this really a working combo ?

Since i noticed there are at least one typo/fault in Arctic Online Parts with the -03 MC 800 drive/reverse dropcase. Both high alt. gearing 19/43 w 24 idler and low alt gearing 19/40 w. 22 idler gearing uses a description field note "72p chain", with different part no. (0602-968 70p, 0602-972 72p).
Other parts stores using data from cat have same fault.

A none reverse sled a 19/40 70p chain is a great combo.

Any suggestions one any other combination s that work ?

/ Johan

 

[JohanL]

Had to check once more, disassembled it once more...
I do have 19T top, 22T idler, 40T bot and 70p chain in my -02 . (chain worn mock-up) Like the -03 MC 800/900. This as previously written, does not fit satisfactory for me right now. Why? Any suggestions?

Stock setups according to Arctic Online Parts.
ONLY setup's for DRIVE/REVERSE DROPCASE listed.

top gear/bottom gear, idler gear, chain

Mountain Cat 800
-01
23/40T, 22T, 72p
-02
23/40T, 22T, 72p
-03
19/40T, 22T, 70p (Miss match chain part no and description)
19/43T, 24T, 72p
-04
19/39T, 24T, 70p/72p (Matching chain to gear combo can not be found from parts list alone.)
19/43T, 20T, 70p/72p (Matching chain to gear combo can not be found from parts list alone.)

Mountain Cat 900
-03
19/40T, 22T, 70p
19/43T, 24T, 72p
-04
19/40T, 22T, 70p
19/43T, 24T, 72p

King Cat 900
-05
19/39T, 22T, 70p/72p (Matching chain to gear combo can not be found from parts list alone.)
19/43T, 20T, 70p/72p (Matching chain to gear combo can not be found from parts list alone.)
-06
19/39T, 22T, 70p/72p (Matching chain to gear combo can not be found from parts list alone.)
19/43T, 20T, 70p/72p (Matching chain to gear combo can not be found from parts list alone.)

 

[Arcticatdan]

Go to the 18-40 it will work with the 70 pitch chain. Have used it and it works well.

 

[JohanL]

Thanks for your info.
Interesting gear ratio. 18/40. I expected 19T to be smallest gear, due to torque and gears in contact with chain. If it works as you wrote, thats nice. I guess a bit higher chain and gear wear, but they can be replaced, as long as it was fun until that has to be done.

/Johan

 

[JohanL]

Put in a 18T gear this weekend as recommended by Arcticatdan. 70p Chain length was a really nice fit for this combo. Only uncertainty is how chain and gear wear will be. 18T is quite small.
(18/ 40T , 22T, 70p)

Cant wait to try it out. Snow please...

Got it out of the garage...

/ Johan

 

[Idcatman1]

gearing

I have been using the 18-40 gearing in my reverse equipped King Cats for years. It works well with the 70 pitch chain. I have three of them with 975 big bores. They also have bigger drive sprockets on the track drive shaft than your 02 came with. 8 tooth 3" pitch verses 9 tooth 2.52" pitch. I have had some trouble breaking chains and am going to try something with about the same ratio with a larger top sprocket and maybe not stress the chain as much.

I think you will like the setup on your sled, it should give you all the bottom end grunt you could ask for.

 

[kidrman]

I have ran this combo for years as well and haven't lost a chain yet. I try and change it once a year just for safety.

 

[justinmaughan]

has anybody run a hyvo 20 top and 46 bottom with a 76p chain. i talked to a guy and he said this was teh best thign he ever did to his sled. said it really woke it up and with the hyvo no broken chains anymore

 

[JohanL]

Thanks, nice to hear that it worked as satisfactory gear ratio for you both. (kidrman, Idcatman1).

Those drivers i was not fully aware of. Had missed out on the 3" vs 2.54" part. A bit lower overall gearing then i calculated for. Cant wait to try it out, can always go back to previous gear ratio.

Frequent change of chain seems like good chain case "insurance".

Have to agree that a 43T gear or something similar would be a better long time choice. That will be the next step. Have to evaluate these gear ratios first. Maybe they are not for me and my riding.

/Johan