1970 arctic cat pather 303 sachs restoration
 

I have 3 arctic cat panther 303's, one of which is my grandfathers old 70' as well as 2 panther 303 71' parts sleds. They only made these sleds for a few years so they're pretty unique, with a 303cc single rotor air-cooled, ~20 hp engine I'll be stripping the 3 of them down and building one from the best of the parts, I have nearly everything minus a good seat, hopefully that can be found at a swap meet or something to that nature. Only my grandfathers engine is the only one that runs and has good compression, but i am hoping to tear down and rebuild the other motors as well. I'll get pictures of the whole process as I go along, I've already started stripping down the first sled.

good luck with your project . can't be very many left worth working on .

Not a lot of guys here that work on this kinda stuff but for sure they are around . Are you going to do some mods or keep things simple ? Maybe open the ports a tad . Don't know much about them just curious that's all . Welcome to the basement .

There are definitely not too many left around. One of the chassis is pretty rough, but if i were to take the time to rebuild the motor and buy a seat for it as well i think i could actually make a decent two from the three.

I'm going to leave the running engine untouched and go for a close to stock restoration on the first one.
Once i get the chance to break into the other engines however, i will probably try to do some porting. There isn't much info out there on doing so, but there has to be a few old timers out there that have done it.

Thanks for the welcome!

Landon303 might know a thing or 2 about those, he built a gokart a few years ago with a rotary from a similar application.

Decided to tear down one of the low compression motors last night. Both side plates were pretty etched up but they're aluminum so maybe thats normal? Nothing that. Can't be fixed though. The housing had a lot of missing Chrome. I'm calling that trashed. The rotor was covered in carbon. Bad. But in otherwise good shape. All the seals were in good shape though one side of the rotors had to corner seal springs to each corner seal. I think it was previously rebuilt and someone screwed up.

I would kinda like to see what you got there , can you take some pics and post ? There was a forum member maybe couple years back was working on one but never followed up .

if you use the search function on rotary snowmobiles there are lots of threads on the subject

pics please !! dont write off the housing either .. while some people are trying replating processes ,
i would be inclined instead to investigate some custom ceramic seals with NRS sven
and try running them directly on a steel housing surface that has been chemically stripped

http:// https://fbcdn-photos-d-a.aka...25295586_n.jpgI researched goopy performances housing resurfacing, but they don't actually add any new material in their prcoess and we're talkong about a lot of flaking. I'll post up a few quick pics from my phone for now I've taken.

i cant open the linked pics :scratch:

the odd dimensions and existing coating will always pose too tricky or expensive
but i have had a heavy hint from someone who would know that the ceramic seal on steel housing surfaces has given a few positive surprises
\and thats all i want to say about that right now :cool:

it may be easier to chemically strip the surface and just go with custom tooled ceramic apex seals ..

My phone isn't making loading pictures easy. I'll have to load them from home.
I can use some modified 12a apex seals, how much do ceramic apex seals run and how does one go about stripping the chrome off of the housing? I still have another non running engine to tear down still. Hopefully that one will be in better shape.

would chat to sven at nrs who does them for all sort of funky wankels .. chemical stripping could be done at any chrome plating place

Wow. At $1000, a set ceramic seals are way out of my budget for this build, especially considering they'll have to be further modified for my application.

chat to him privately.. you only need 3 !!
he does do them for wankels you dont even know the name of yet
and i suspect that this is still the cheaper option if it allows you to get use out of damaged housings that are not obtainable anywhere else

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So cool! I would try to get those housings machined to an even surface. Don't really worry if the housing is chrome smooth as they will be lubed with premix and they aren't turning as many miles as a car engine.

curiously on the re5 suzuki engine they have some sort of teflon / graphite impregnation on the side plate that is laid in orbit patterns very much like the scoring seen on that side plate
( yours maybe due to excessive endfloat or rotor bearing clearance i suspect )

im in nearly the same camp as customisbetter .. machining it flat and using a different seal and lube combo on the existing surface
( etching the chrome away at the chromer may be simpler as its a custom trochoid shape , and the ceramic apex seal is lighter and self lube to some degree and shows most promise here ,, plus sven has his finger in the dressing and rechroming thing too )

The nice thong about these engines is theyre air cooled so you don't have to worry about replacing all sorts of gaskets for a rebuild. All that matters is the bearings and rotors seals so if it doesn't run its no time at all do do it all over again.

wow, its pretty different from the evinrude versions

havent touched the sleds in a while, college work and trying to maintain a social life has kept me pretty busy. I did However pick up a 1974 Arctic Cat Pather 295, also rotary, puts out a whopping 24 hp!

Never thought about it before but I remember the machines being around , I bet there are more sitting in the tree lines than one thinks . 24hp would turn a big old fatty tired bicycle into a big old bullet , huh