My new project Sierra T-Boss

[Bazooo guy]

The larger diameter secondary will give you more bottom end torque.
High gear will be the same as long as the secondary can open wide enough.

[thebuggyman1]

The larger diameter secondary will give you more bottom end torque.
High gear will be the same as long as the secondary can open wide enough.

Just to clarify.....it would be like having a car with a stick and losing your 1st gear........Big v-8, no problem.....little gas sipper, big problem

How's the low end torque on that 440?

[Bazooo guy]

Its a 2 stroke so it probably will have good power around 6000 rpm.
Depends how the final drive is geared but i think you should be ok.

[Big Sal]

I suppose the 440 is pretty strong on the bottom end being a twin cylinder....the sled it came from was an Arctic Cat Panther...top of the line in '74...and a pretty heavy sled to boot...I figure most of these machines are running 20+ inch tires where as mine has 18's, so the gearing will naturally have to be different to compensate for the smaller tires...

[thebuggyman1]

The following is copied from the Dayco Belt web site: ATV and Snowmobile Belts - by Dayco
Tech Tip #3: How Over-Sized Tires Affect Clutching
Oversized tires have a lot of benefits, such as better traction and performance and greater ground clearance. The down fall to these tires is loss in power, throttle response, and increased belt slippage.
Usually, oversized tires weigh more than the stock tires the machine is set up for. It will take more power to turn the extra weight. This is where it helps to use lighter weight rims.
Most oversized tires will offer more aggressive tread, which will make it harder for the motor to turn the tires. Even if the tires and rims are lighter than your stock tires, they will still start out in a higher gear ratio due to the taller tire. With the extra weight, traction, and height there is an increased strain on the clutch system causing belt slippage.
I take this to say that tire weight and aggressive tread mean more than tire diameter.

I included the link because there is a lot of good info there.

[Big Sal]

Good stuff...so basicly the article is stating that the larger tires do affect the final ratio....and the fact that a lot of machines run 20-22 inch tires and a 9-9.5 dia driven and mine running 18's and a 7.5 driven, I'm assuming the smaller secondary should compensate for the smaller tire size....everything being relitive, but proof is in the pudding as they say....I'm going to fab it all in and see what's what, nothing to it but to do it...lol

Just to clarify.....it would be like having a car with a stick and losing your 1st gear........Big v-8, no problem.....little gas sipper, big problem

How's the low end torque on that 440?

Believe it or not it moved ok with the 10 horse Briggs in it....just not fast...I don't know the torque numbers, but I read the engine is around 35hp at 6000 RPM's at the crank...so it should have enough low end in it....

Here is a link to a Wiseco top end kit for the 440 Kawasaki sled engines....

Wiseco Pistons for Kawasaki Engine | Hi-Performance Engineering

[Bazooo guy]

oversized tires weigh more than the stock tires the machine is set up for

If it was set up for a 2 stroke with the same tire size it will be fine.
You will know the first time you drive it.

[Big Sal]

It was Bazooo....the owner before me had taken out the siezed 2 stroke and transplanted the Briggs engine, but the original was a 297 Kohler 2 stroke...

[Big Sal]

Well got my "new" rollers in the mail for my clutch, gotta love NOS parts!! Gonna pick up the assorted pieces I need to fab in the engine mount this weekend...hopefully by Sunday I'll have it mounted in and running then next comes changingout the fluid in the trans and the exhaust, the sled exhaust is kinda big, so I've been checking out smaller ones on ebay...any suggestions?

[Bazooo guy]

Keep the exhaust as close to original as possible.
The pipe length and expansion chamber are important for the performance of the engine.

[Big Sal]

So I've read....the ones I've been looking at are used units from other sleds with around the same CC's as my engine....

[Bazooo guy]

You will most likely need to modify it to fit.
Try not to change the length of pipe between the head and expansion chamber.
I made a simple y pipe and cut out a 90 to modify my exhaust and it works and sounds great.

[Big Sal]

Well I was tinkering around with my new project and popped the plug on the T-20 and guess what I found inside??? Yep you guessed it....milky white GEAR OIL!!! Now I have to pull the trans and rebuild it....I'm done with this project....between all the custom BS I'm messing with and now the trans needing to be torn down, I think I'm better off parting it out and use the proceeds for something else that's "unmolested"....I'm about $450 deep in it right now, if I sell off the trans and the engine maybe I could break even, then sell the machine as a parts donor...I hate to be beaten down...but I don't think it's worth investing the time and money into...

[thebuggyman1]

Relax, You are a little premature on the t-20. Split it apart and look at the components.....especially the drums. If the drums are rusty from moisture in the fluid, yes it will be expensive. If there is no rust, mic your bands, check the bearings, and go from there. It is a good idea to replace the seals when it is apart, but not a MUST do! You could be looking at nothing more than a couple of case half seals @ $8.

[Big Sal]

I thought once the bands were dunked in gear oil they unglue themselves? Being a Sierra Trail Boss, you really think it's worth putting the time/cash into?