Kids Mountain Ovation 340 136"

[AMAX]

Bought a decent 1996 Ovation last winter. They are about 2/3 the size of most sleds, fan cooled and have good reputation for reliability. Electric start and hand warmers were a plus.



My then 8 year old loved it and had a blast but the combination of a 108" track, tiny lugs and a 340 @ 11,000' meant playing in powder and off trail stuff was pretty limited.



We swapped in a 136" skid from a '96 Phazer, geared it down with 7 tooth drivers and dropped a tooth on the small chaincase gear. Chopped the windshield, chopped the seat, repositioned the handlebars and gave it a bright paint job so he stands out better coming around a corner on the trail.













We have a few odds and ends to finish up like plastic skis, a better tunnel extension, a flap and rear bar, but it rips around the yard great! Somewhere between gearing and flushing the fuel system it really woke up. If it runs as good at elevation, I think it could turn a 1.5" track.

 

[AZ800]

Nice job! That looks friggin sweet. Your son must be very proud of it!
Another suggestion to get the most out of the 340, port the chit out of the track.
I stuffed a 136x16 track under my boy's 380 Doo. Clearance on the side of the tunnel is super tight, had to grind some rivets down lol.
I installed it without drilling the track and after getting it aligned perfect and some grinding on parts that were hanging it up, it still took a good pull to spin the track by hand.
Put 5 holes in every row, outside belts and 3 in the center. Unofficial analysis was it spun about 1000% easier haha.
No worry about blowing the track apart on a little fan sled anyway.

 

[AMAX]

A few specs to help anyone doing a similar swap:

Drivers are Kimpex 04-108-50. 7 tooth 2.52 pitch.

Rear skid mount hole is 33 1/4" from the front skid mount hole center to center. The Phazer rear bracket has a hole at 6 3/8" from the top & an optional hole an inch lower. I split the difference and went 7".

Front skid mount hole distance from drive shaft and distance from the top of the tunnel are the same on both sleds.

The Phazer II ran 2 sets of upper idler wheels. I'm going to see how I does without them but they would be easy to add.



11 tooth chain gear is 802-17682-20-00

Thanks to Aerosled for measuring his Phazer II since I didn't have access to the donor sled chassis.

 

[AMAX]

I stared at it with the drill in hand today considering porting.

I didn't commit but might after our first real test. Glad to know it helped 'cause this track is a lot heavier than the little 108".

 

[sno*jet]

love it!
once you get some plastic skis on there i think he will really notice the difference. i rode a 340, then a phazer with steel skis and the steel would stick when i stopped and make it hard to get going again. and they darted all over the place unlike a concave design.
i would keep track porting to a minimum in case you want to show him how to cross water with it soon. start on some puddles, that 340 at wide open can do it!
i removed one set of the upper tunnel wheels on an old yamaha, but found it needed at least one set to keep it from bouncing in there.
you can replace those heavy cast idlers with plastic ones too.
nice job.

 

[Merlin]

Bought a decent 1996 Ovation last winter. They are about 2/3 the size of most sleds, fan cooled and have good reputation for reliability. Electric start and hand warmers were a plus.

We have a few odds and ends to finish up like plastic skis, a better tunnel extension, a flap and rear bar, but it rips around the yard great! Somewhere between gearing and flushing the fuel system it really woke up. If it runs as good at elevation, I think it could turn a 1.5" track.

I installed a 136" X 1.75" track along with 7 tooth drivers on my son's Indy Lite last year.

He only got 1 ride on it last season with those mods. but I can tell you swapping the 7 tooth drivers for the factory 9 tooth drivers was a significant, albeit needed, improvement.

IMO, you're on the right path! if the plan is to install a longer, deeper lug track on any of these small cc, fan cooled machines, it should be accompanied by gearing the machine as low as possible. No need for the machine to be set up for 60 + MPH.

 

[Frostbite]

I did a similar mod in 89-90 on my wife's new Ovation. I sold it when she moved up to a Phazer 500 and the kids were way too young to ride it. I just bought another one for my very petite 100lb. daughter. It already has a 121" skid and drivers. I will have to play with the track lug height and see what size drivers are on it.

What I wanted to share that maybe some don't know is that Aaen Performance still makes a pipe for the Ovation. It saves 10 lbs of weight and give a 5 hp boost that you can really feels. I had one on my wife's Ovation back in the day and I remember I had to order the largest jets for the strange little carb that Yamaha had available. I also turned the intake snorkel around and cut another hole on the hood with frogskin over it so the engine could get more airflow. That little sled sounded SO cool. It was a real kick to ride.

Here's a link to the Aaen pipe:

http://www.aaenperformance.com/Yamaha.asp

 

[AMAX]

Update: Sled gets around pretty darn good. Still messing with getting better response coming off idle at high altitude but for under $1000 it makes a really fun small sled for a kid.



First lesson in the magnetic pull of trees.

 

[Merlin]

That's awesome & good snow conditions to boot!

"The magnetic pull of trees" is good one & so true. It's goes hand in hand with "If you focus on that tree well / hole, you're going to drive into it!" LOL

 

[volcano buster]

Update: Sled gets around pretty darn good. Still messing with getting better response coming off idle at high altitude but for under $1000 it makes a really fun small sled for a kid.

First lesson in the magnetic pull of trees.
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I love the project.

I also checked this yesterday on my phone and the picture was so small I thought he was gesturing that you were number one for building him a sled. After zooming in I see he was politely saying "Thanks Dad, you rock".

 

[lasse]

Update:
Still messing with getting better response coming off idle.

Throw that odd and funky "Teikei" carburettor in the trash can and put in an ordinary Mikuni VM-32/34 instead.
The little 340 will run so much smother, better response and no hesitation or bog.

 

[AMAX]

Lasse:

In looking for answers I saw that on an older thread somewhere about you making that conversion but the pics were gone. I need an intake, carb & what else?

I'm about done fighting this carb.

Thanks

 

[AMAX]

Update: Went through the funky carb and adjustments and have it running really well at 5000'. Haven't been up to our normal riding spot (10,500') but thats where I fight getting it to run as good. I'm maxed out on jetting options. May do some sort of reversible airbox mod to see if I can get it leaner up there if it shows the same symptoms as last year. I would like to avoid a Mikuni carb swap until the off season.

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[AMAX]

Ditched the metal skis and put on a set of plastic ones I had in the garage from an '05 Summit. Had to cut the old bolts off as they were rusted to the spindle bushing. Ordered a couple new bushings and used the SkiDoo bolts (same dia. M10). The spindle is about .180" narrower than the ski bracket so a couple washers worked great for shims. Trimmed about 1/4" - 3/8" off the bottom of the original rubbers. We'll see if that works. They conform to the bottom of the spindle pretty well. They are smaller than the pocket in the skis but I left enough height so they are a snug fit.



UPDATE: Two rides on the skis so far and trimming 3/8" off the bottom of the stock Yamaha ski rubbers is working well and they are staying in-place. He likes not being frozen to the ground when he stops.

 

[Merlin]

I'm thinking of venting the carbs to the air box on my Indy Lite. Then install "tee" fittings in each of the lines between the carbs & the air box with caps that can be easily removed on the trail.

Leave the caps off at lower altitudes / colder temps. & then install them as the ride takes you to higher altitudes / warmer temps......Kind of a manual altitude / temp. compensator.

Just not sure how much the signal from the air box will affect the mid / high speed mixture?

Only one way to find out I guess. LOL

Update: Went through the funky carb and adjustments and have it running really well at 5000'. Haven't been up to our normal riding spot (10,500') but thats where I fight getting it to run as good. I'm maxed out on jetting options. May do some sort of reversible airbox mod to see if I can get it leaner up there if it shows the same symptoms as last year. I would like to avoid a Mikuni carb swap until the off season.

 

[reignman]

I love the 340 mod project and I plan on doing one this summer if I can find an Ovation.

Currently my kid rides a ET250, but is getting beat to death on the trail. I did swap to the Mikuni and it runs a lot better.
She wants to learn how to jump off the trails edge and hit the powder so she needs a little more power and a 136".

Thanks for all the info!

R

 

[AMAX]

looks like Photobucket broke my pics.

The Ovation is still going strong but my son is now 13 and pretty sure he's ready for a big sled.

 

[couch]

New skis are a must ...loose the steel anchors ...makes a big difference ...did a couple of ovations with 121 1.25" lugs and they were great ...

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