I have a 2005 zr900 efi. I bought a D&D 1010cc top end for it, and
I want to stretch it out to 136". This will hopefully help with the traction.
I know little of the suspension, and wondering if there is a rail kit for
my sled? I can manufacture the tunnel extension, but I wanted a
bolt on rail set-up. I don't know wether I need bigger wheels or not?
Hope somebody can lead me in the right direction. I gathered a lot of
parts and don't want to waste any power, plus I like off trail riding too.

I don't think I would do it if I were you unless you ride deep snow/powder/mountains...

To answer your question, You'll need rail extensions (tracksusa.com), a 136 x 15 x ??? track, and a tunnel extension. I had a problem finding a tunnel extension for my 02 zr 800 CCE, Vanamburg made one for me and I sent it back and scrapped the project because it was such a hack job..

I've seen a ton of homemade tunnel extensions that look far better than most. The extension will be your biggest problem, bigger wheels aren't needed unless you want to upgrade.

Also remember with the 1010 you'll probably want to add or extend the heat exchanges to keep the motor cool :div20:

I rode a four stroke 660 with a 136" track and didn't notice a dfference, except in the powder, his didn't sink like mine did. I planned on using the tunnel extension to build in a new heat exchanger. I only want a 136"x15"x1" so as not add too much drag, but help with traction in dragraces.

i think you can get a kit from an ac dealer. I think it was snowmobile world had a whole article on how to strech out a zr to a 136.

sounds like a "waist of time and money" mod for you, for one you say you didnt notice a difference untill you went onto the powder well a 1" lug track wont do you any good there and as far as drag racing goes you actualy only end up with about 3" more of track on the ground and unless you are running picks or chizzles forget about drag racing. im not trying to be an ass but i went through the same thing as speedy and me and him both know that if you have trail studs and your drag racing well your screwed :banghead:

Thats the advice I'm looking for. I did a lot of backyard dragracing on ice last
winter with onlt 192 megabites, angled backers, and long aluminium nuts.
I hooked up good, but with all the power I am going to gain I don't want to waste it. I see some drag sleds with a longer track, and thought that might be for me. As for the powder my sled didn't go as good as the 4 stroke, and his track is only 1" lug. I thought it would be a good comprimise for off trail, and drags. If not I may
spend the money on something else?

actually 121" to 136" puts about 7"-8" more on the ground.

jest buy a ripsaw they work awsum

I do not know if the kits are still offered through Cat, but they DID have the full extender kits for ZRs in about 2000. The kit included a rivit-on factory-style painted tunnel extension, heat exchangers, and longer rails. All you needed was a track. I thought it was a good idea. until I found out it was around $600-700, plus track. I never did it.

It would have added around 6 inches of track on the ground.

HpHunter,

I took my ZR8 from 121 to 136. Yes, you do get WAY better traction, you have more track on the ground, and maybe more studs. Yes, it does work much better off trail, in fact, it's a hell of a lot of fun. It even works a bit better on-trail by flattening out some of the stutters. If you can make your own tunnel extension, pretty much all you need is the track and rail extensions. TracksUSA makes the best rail extensions, IMO, and he makes them for 8 inch wheels (a little less rolling resistance). A lot of guys like the 136 Ripsaw track. I wouldn't go back to 121 for anything. If you want to know more, PM me.

JUST DO IT !!!!!!!!!!!!!!!!!!!!!!!!!!!
I DID MY 05 900 the day I brought it home! I works better in every respect!Plain and simple. You can go thru stuff you never dreamed of! I had a sheet metal (heating and cooling)shop bend my tunnel extention,and it cost $80.
I did go to 8 inch wheels ,butit is not a mandatory thing.It would have gone alot faster using the stock wheels,because you will need a mountain cat axle,and the spacers to make the 8 inchers work.Not a big deal. The axle is $20 and the plastic spacers(same as on a fire cat used at the axle adjuster) are about $3 aach . you need 4 plastic spacers,and the long aluminum tube from the mountain cat.Also you need the big washer that goes at the end of the alum.tube spacer.
I did not extend my cooleers,but will do it before this coming season,as mine got hot a couple times in low/no snow area's.
I have complete pic's of everything if you need them.

Im doing it to mine...running a 1.25 ripsaw 136" on it, dont know if im going to swap out tunnels compeletely or just put an ext on....im thinking of going with a newer style mc tunnel because the foot boards are wider.

If you're doing the 136 for traction, it's the wrong way to go about it...get a shaved 1" with a good chissel set up and you will be more than fine on a 121"..

Looking for best all round situations in my case. I don't want to change tracks in the winter. So I thought a 136" would be a good compromise, for traction on ice, powder conditions. I know it won't do both great. But all I race is 1/4 mile at most, on whatever conditions. I also like to be adventurious. Thats why I came up with th 136" with a 1" lug height.
I dunno I want it all.

Trail studs are the worst thing for drag racing. Picks or chisels with a shaved track is the way to go. You cant have the best of both worlds unless you change tracks. Good luck

if you trail ride and race on snow go 136". if you race on ice and dont trail ride much then go with chisels on a 121". a 121" will not hook nearly as hard as a 136" on snow. studs dont do anything in powder either so chisels wont help there. i would go 136" with a ripsaw. it will take a little off your top end, but will be awesome in all other conditions with an unbelieveable holeshot on snow.

Yes the 136 is well worth the update!!! You get a much better ride and alot more traction then the 121. Yes the 121 with chisels work well for drags but not worth a S@## for HP trail riding!!! The Camo 9838 is a 1", six pitch track along with 162 Wood's 1.175 studs will smoke any 121 on the trails. Some people have no clue what works !!!!!!!!! :frech32:

What was wrong w/Vanburgs Tunnel Extension
I heard he has the best.........Email me or qoute it here :beerchug:

Just do it! You won't be sorry. Best all around mod you can do for the ZR in my opinion :beerchug: I installed a cat 136" extension with a 142" track with 2" lugs. I have since gone to a 136" track with 3/4 full lug and studs. :augen41: It's better in the snow than the 121" by far. Stay smaller on your lugs to keep the weight down. With the 136" track I take most all ZR's on the hole shot and most on top end as a matter of fact. "Get er done!"

That article was from me when I extended my ZR. It was by far the most satisfying thing I've done to my sled. I ride the trails of Wisconsin and the UP, plus the powder of the UP. I will NEVER own another 121" sled in my life. I gave up NO handling (after proper setup) on the trails and the off-trail fun factor is unbelievable. Here is a link to my story. If you have any questions, please email me, snoblazer@charter.net.

136 upgrade

been there done that , and going to do more :div20: