Hustler engine upgrade

[bugeyed_99]

So ive got it narrowed down to a hirth 2 stroke or or a rotax 503 for my engine upgrade from a 486cc polaris snowmobile engine. any suggestions? Im leaning towards the hirth.

[whitefisher]

so ive got it narrowed down to a hirth 2 stroke or or a rotax 503 for my engine upgrade from a 486cc polaris snowmobile engine. Any suggestions? Im leaning towards the hirth.

503 rotax... Im just finshing up my 503 install,, test ride ,lots of power great low end ,lots of parts out there.....building custom 2in. Exaust for more flow on top end..exp.chamber spark :suppressor

[bugeyed_99]

The 503 is a 2 stroke as well right?

[hydromike]

They are both two stroke engines. The Rotax is the superior choice if you have to choose between it and the Hirth. The 503 will deliver between 50 and 52hp in the single or double carburetor configuration. The Rotax is still being produced today and has a huge following in the ultralight aircraft, hovercraft, air-boat and snow-machine crowd. Parts are readily available and they're really a robust engine for their size and simple technology (axial fan, no reed valves, no rotary valves, frequently breaker-point fired, blah-blah-blah....)

I've been running one in an Attex for over 10 years, and I still get twitchy behind the sticks. I was lucky enough to drive a Hustler 950 at Ashtabula last fall that was 503-powered. It's an absolute animal. I hurt it, it hurt me.

::EDIT:....

This is a video of Don's Hustler and Matt's Starcraft.... ignore the me-crashing part; this is just to show you the potential....

[jpswift1]

503 Rotax all the way!

[bugeyed_99]

I plan on installing the 503 into the hustler next week, I am going to stick with stock sprockets for now but am considering changing the springs for the time being, Im thinking red springs? Ideas? its just going to be used for fun, trails, no water or pulling logs or anything. are they just common red clutch springs, or where do I find them. I didnt post in the transmission section cause I didnt want to start another thread in addition to my multiple ones already

[bugeyed_99]

Ive decided I dont like the look of the stock rotax 503 exhaust so I need some input from the 503 experts, will a duel exhaust system work on a 2 stroke 503? I just want the pipes to come over the top of the engine and straight back towards the rear, feasible with no performance lost?

[bugeyed_99]

Im looking for a wiring diagram for the rotax 503, Ive searched through the user manual and tried to google it but no luck, Im hoping someone that has installed one has a diagram they can share. Im just looking to wire in headlights, tail lights, a winch and an elec starter