Rotax 299cc???

[Brmorgan]

OK I know this isn't DIRECTLY chainsaw related, but... I came across this little Rotax engine in the scrap bin this morning on the way to work. Freebie:

The topend looks great through the intake port, and it makes really good compression; it's pretty tough to turn over by hand. The top of the piston clears the top of the intake port by about 1/16" at BDC. What do these need for a carb? I have a couple big old Tillotsons (I can never keep HL and HR straight, so I can't remember which they are) that I've salvaged; would they possibly work? Finding a float carb wouln't be an issue, failing that.

How are these engines for modding? I assume a tuned pipe would be pretty sweet, but I know nothing about that yet.


I have three options for this engine if I can get it running: build a go-kart, play around with some kind of hotsaw project (after I learn more), or use it for milling somehow. I've always wanted to build a kart and this would be perfect for that... I'd probably kill myself with it though. Not that a 300cc hotsaw would be any safer in my hands!

 

[nmurph]

can't help you one bit, but that motor is cool.....good luck......rep sent

 

[mirkaba]

Beauty!!! I had one . It came standard in the 1967 Super Olympique Skidoo. (699.00 New) Had a recoil start and centrifical clutch. Looks like the original muffler. Remember it had a Tillotson carb and I was always messing with it. Used to carry a spray bottle in the toolbox for when it didn't want to start. There are still parts out there. Try your local Skidoo dealer! Bob

 

[Jacob J.]

That's the kinda stuff I'd like to find in the scrap bin...

Those older Rotax motors were great motors. They were made to a high level of quality and produced good power although they're a bit heavy compared to more modern motors. That's the perfect engine for a minibike or go-kart or custom milling rig.

As far as carburetion goes, an HR would be the better choice. Most of the HLs simply won't move enough air and fuel for that much displacement unless it's a low RPM motor. If you end up needing an HR, I have a few in my odds and ends box, along with some big Mikunis.

 

[jnl502]

that little rig is so sweet i could see all kinds of ways to hurt myself with that make us proud!
jnl

 

[pioneerguy600]

Good find Brad, I see a Hot Saw project in the future. LOL
An old Olympic skidoo I have has one of those Rotax engines in it, I changed the carb over to a Mikuni from a motorbike, it worked better than the old bytterfly carb that came on it. The carb came off a Suzuki PE250 if I remember correctly.
Pioneerguy600

 

[Stihl051master]

Pretty sure the 300 used a Tillotson HR carb. You could get a flange pretty easily and put a Mikuni carb also - just need a fuel pump. There are lots of parts around for those engines around. If you want to put a pipe on it, look for one from something that had the same stroke. There are lots of dirt bike pipes out there that would work, or one off of a twin cylinder snowmobile engine. That would really wake the thing up.

The one lunger snowmobile races are really popular around here, and you can get a surprising amount of power out of one of those engines.

 

[Madsaw]

That's the kinda stuff I'd like to find in the scrap bin...

Those older Rotax motors were great motors. They were made to a high level of quality and produced good power although they're a bit heavy compared to more modern motors. That's the perfect engine for a minibike or go-kart or custom milling rig.

As far as carburetion goes, an HR would be the better choice. Most of the HLs simply won't move enough air and fuel for that much displacement unless it's a low RPM motor. If you end up needing an HR, I have a few in my odds and ends box, along with some big Mikunis.

LOL
If you only lived closer JJ. I still say a road trip is oder to your place. I have one of them little engines setting in storage. Complete carb muffler and starter. But then again it should not weight more then the disston.
Bob

 

[Mastermind]

Get it running...bolt on a B&C...chase the husky boys right outta the woods... Yea this CAD is getting crazy.

 

[Jacob J.]

LOL
If you only lived closer JJ. I still say a road trip is oder to your place. I have one of them little engines setting in storage. Complete carb muffler and starter. But then again it should not weight more then the disston.
Bob

Bob-

We'd have to rent U-Haul trucks to get our goods back and forth...

I'll bet I can come up with something neat to trade... I'm thinking a 395 Big Bore saw with a Stihl 076 Super piston in it...

 

[Madsaw]

Bob-

We'd have to rent U-Haul trucks to get our goods back and forth...

I'll bet I can come up with something neat to trade... I'm thinking a 395 Big Bore saw with a Stihl 076 Super piston in it...

LOL Naw I will pass on the U-haul. I will just put overloads on the old diesel and head out. If your serious about the rotax I got here I will get it out and check it over this weekend. Suppose to rain again. Hope to have some corn in the ground before then though. We can work some thing out. Might even do some checking on doing a freight shipment. Might be cheaper in the long run.
Bob

 

[Jacob J.]

LOL Naw I will pass on the U-haul. I will just put overloads on the old diesel and head out. If your serious about the rotax I got here I will get it out and check it over this weekend. Suppose to rain again. Hope to have some corn in the ground before then though. We can work some thing out. Might even do some checking on doing a freight shipment. Might be cheaper in the long run.
Bob

We're planting tomatoes right now... it'll be time here for corn later in May. Growing season is starting later here this year but is forecast to run later as well, long Indian summer this year...

Let me check with my cousin, he works for CSX. I'll bet he could pick some stuff up from you and drop some stuff off for you.

 

[Madsaw]

We're planting tomatoes right now... it'll be time here for corn later in May. Growing season is starting later here this year but is forecast to run later as well, long Indian summer this year...

Let me check with my cousin, he works for CSX. I'll bet he could pick some stuff up from you and drop some stuff off for you.

We are early this yr for crops. Got the oats in on the 2nd of April. If everythign was ready we could have have some corn in last week. But they are calling for frost tomorrow night. Should get about 23 acres in thursday. Then plant some later silage corn in 3 weeks. Will be real strange with having corn in this early.
That would be great deal with CSX. I got 2 or 3 places I can ship and receive from with freight trucks. All with in a stone throw of my place.
Thanks
Bob

 

[eyolf]

IIRC, that motor was rated to produce 12-16hp...average for the day. Up 2hp from the 248cc engine. My book says it took HR7A Tillotsen in 1969 as a 12 hp. I think some came with an HD and made 16hp in the Alpine.

I don't think it would make any kind of hotsaw. Ist off, it is too heavy, weighing about 60 lbs. There were a couple of other problems; not enough ability to keep cool at higher power levels, cast-iron cylinder bores expanded less than aluminum pistons, and rotating/reciprocating parts were heavy. Certainly no more than around 6000 rpm.

 

[Mastermind]

IIRC, that motor was rated to produce 12-16hp...average for the day. Up 2hp from the 248cc engine. My book says it took HR7A Tillotsen in 1969 as a 12 hp. I think some came with an HD and made 16hp in the Alpine.

I don't think it would make any kind of hotsaw. Ist off, it is too heavy, weighing about 60 lbs. There were a couple of other problems; not enough ability to keep cool at higher power levels, cast-iron cylinder bores expanded less than aluminum pistons, and rotating/reciprocating parts were heavy. Certainly no more than around 6000 rpm.

Well...Crap

 

[Jacob J.]

Well...Crap

lol...time to start thinking of ways to hop it up...I'm sure people have already tricked these engines out before.

 

[Mastermind]

lol...time to start thinking of ways to hop it up...I'm sure people have already tricked these engines out before.

You need to get outta my head...it's dark enough in there.

 

[Brmorgan]

I dunno, I certainly didn't think it felt all that heavy for its displacement, even compared to my 090, and that's WITH the big torque converter clutch. Doesn't look any clumsier or heavier than some of the one-man bike saws I've seen here and elsewhere. I do have some ~28-30" harvester bars that I salvaged that are still serviceable for a while.... I have a huge stack of spare nose sprockets for them that I found too.

As per the max RPM, I wonder if you could lighten the piston very much to help with that? Cooling shouldn't be an issue if I were to use it for a kart, as long as i design it properly. Nor do I think it would be for short intermittent runs. Not like I'd be bucking cordwood with it if I did build some kind of saw.

 

[Mastermind]

Whatever you decide to do with it, just have some fun. I try real hard to have a good time everywhere I go...no matter who I'm with.

 

[Brmorgan]

lol...time to start thinking of ways to hop it up...I'm sure people have already tricked these engines out before.

I did a search and found various vague references but no pictures or videos.

There is one on Youtube of a 220cc saw built from half of a 440cc twin Rotax here:

<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/d4R91PIFS8U&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/d4R91PIFS8U&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>

It revs out pretty decent!