working on a new engine

dantheman · Post by **dantheman** » March 3rd, 2005, 12:59 pm

well after i have re-designed most of the drivetrain on these sleds i set out to put a little more oomph under the hood.
i am anxiously awaiting the new engine to show up in the morning
i opted to find some more hp for a lot less $$$ than it costs to replace the crank, i found an engine that has almost twice the hp and the size of the package only grew anout 3 inches, now ill have to make a custom mounting plate and possibly custom mount the gear reducer to this engine, but having my own machine shop in the garage makes this a pretty easy task, ill let ya know how it goes, the engine i ordered is a
hsk845 or th139 its 139cc engine and i think it will suit well, ill post the pics as soon as i get the plates made and get it mounted, anyone feel free to email me if ya need any custom parts
dan

roger · Post by **roger** » March 24th, 2005, 4:01 pm

I've got one coming too. Can't wait. I'm even going to try and mount the electric start

roger · Post by **roger** » March 24th, 2005, 4:01 pm

let me know how you made out... rchares1@maine.rr.com

dantheman · Post by **dantheman** » December 5th, 2005, 7:45 am

well i posted some pics of the assmebly, im going to post a movie and some better pics next week, but man does this thing go
I modified the engine a bit, added a 25mm mikuni round slide and modified the muffler that came on it
http://spaces.msn.com/members/KITTYMOD/

MachJeff · Post by **MachJeff** » December 5th, 2005, 10:40 am

Thats a serious mod. Nice looking mount, and even a nice brake set up too. Any more details you want to share? What kind of motor is it, what is it out of? What did you use for the brake & clutch assembly? I'm guessing that with that much work into it it will be raced.

dantheman · Post by **dantheman** » December 5th, 2005, 11:09 am

i am going to post a short movie so ya can see how fast it runs,
it actually didnt take much to make the stuff to fit that all in,
its a techumpseh hsk139 snowblower engine, its not the small one
its 139 cc air cooled 2 stroke, i changed the stock carb to 25mm mikuni round slide a comet cvt and reworked the gearing a bit, i had to make a custom weight for the comet since it was originally designed for 4 stroke
but man does it haul, we are not racing the machine,i just do this stuff for fun, actually my kid is 7 years old and i think this will be the last season he rides this one, he is getting too big for it, i think a 120 is in store either after the holidays or next season,
the brake is custom, i machined all the mounts the shaft and the housing all in about 4 hours it bolted all together and fit real nice, i will post some nice closeups so everyone can see how good this actually fit in and the entire engine is cheap, the only weak point i see now is going to be the track drives, so i intend to machine a nice set out of nylatron and replace them and add an outer aluminum clam shell type clamp to keep the pins form coming loose .

MachJeff · Post by **MachJeff** » December 5th, 2005, 11:44 am

You're crazy, thats awesome. I've never seen a 2-stroke snowblower before. Where'd you get the engine from?

dantheman · Post by **dantheman** » December 5th, 2005, 12:27 pm

sure you have its out of the larger toro snowthrower
you can obtain one from smallenginewarehouse for 175.00
look for th-139 or hsk-139 it says 5 hp but if you change the carb and jet it right you can get 10 real quick as that is rated at 1/2 throttle because that is where its governed from the factory i dont remeber what the rpm was but it works great

dantheman · Post by **dantheman** » December 8th, 2005, 7:16 am

your right that would probably be a lot of fun, but i have my doubts that even a modified 120 could keep up with this machine, i plan on taking a video as soon as we get 5 or 6 inches of snow, wich by the way doesnt even slow this thing down like it used too, i also added a fuel tank in front of the sled, nice aluminum tank holds about 3/4 of a gallon due to the waaaaay increased fuel consumption, im going to take some nice closeup pics this weekend, i also had to add vents to the hood to get some cool air into the engine compartment, to say the least i have had a ball working on this project, it has been a lot of fun and i really enjoy this crap

dan

dantheman · Post by **dantheman** » December 10th, 2005, 12:02 pm

ok i have it copmpletely finished check it out now i had to add some vents to cool the engine down, here are some updated pics of the drag machine lol, we are heading up right now to get some pics for the track since now it spins so fast it doesnt grab too good

more is always better
dan

http://spaces.msn.com/members/KITTYMOD/

Roger · Post by **Roger** » January 26th, 2006, 11:33 am

Dan, What did you use for jets in the carb?? I have not got around to finishing mine but I'm going to....

dantheman · Post by **dantheman** » January 26th, 2006, 11:51 am

well i replaced the carb that came on it with 25mm mikuni wich i bought brand new in a box from some small atv dealer on ebay it had a 150 jet in it and i had moved the needle to the second groove from the top since it was still a bit rich in the mid range, the egt was stable at 1100 and since we dont race it i wasnt going to get it to the 1250 range where i usually run things for racing 2 strokes. i also threaded and plugged the compression relief hole with a setscrew, look in the exhaust port right in the top in the center you will see a hole thru the cylinder wall about 3/16 diameter, i would tap it with an M6 thread , do not tap all the way thru you want to bottom the setscrew out on the end of the thread, then shop peen the top edge to it cannot unscrew itself from vibration, there is no risk of blowing a head gasket cuz there aint one on it, that will give ya a few extra lbs of compression and a way better throttle resonse, another tip dont use high octane gas as that engine had no advance and it starts to break up toward the top end, i mix the fuel around 40:1, i wouldn't gop to 50:1 just because i had the crank out and the rod bearing on this engine is not very hefty for abuse, remeber this was designed for a specific purpose to run half throttle to move snow

well it still moves snow just not the way it was intended
dan

Roger · Post by **Roger** » January 27th, 2006, 12:11 pm

do you have a picture of the intake manifold you must have had to make? Also, I found an exhaust mainifold off an old rotax sled that has very near the same port size and it does bolt on. A little dremel work and the ports match perfect. Problem is I got it in a box of parts so I dont know what it came on. I have a Yamaha KT100 Pipe I'm going to use.

dantheman · Post by **dantheman** » January 27th, 2006, 4:51 pm

i used a 1/4 thick pc of aluminum and matched up the ports a bit thats all i can tell ya im not takin int apart to take a picture hehe its a pain to take
out , i used the stock muffler that came with it i just added a pc of tube to put it thru the floor

dan

Skidootoronto · Post by **Skidootoronto** » February 10th, 2016, 5:39 pm

I just did the same swap will post pictures as soon as admin lets me[/img]

Skidootoronto · Post by **Skidootoronto** » February 11th, 2016, 9:31 am

Here are some pictures of my swap

Skidootoronto · Post by **Skidootoronto** » February 11th, 2016, 9:33 am

If you have any questions feel free to ask

Skidootoronto · Post by **Skidootoronto** » February 11th, 2016, 9:49 am

Any requests on pictures let me know

Kitty Cat Snowmobiles

working on a new engine

working on a new engine

goes like lightning

dantheman

engine

runnin fast

updated pictures

carb

manifold

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