This is my thread from BN that I thought I would post over here as well. I tried to clean up most of the "extraneous" stuff but let me know if something doesn't make sense.
I have had the buggy for 3 years and never once did I have a complete trip without at least one break-down.Sometimes it was a simple fix and sometimes it sidelined the buggy for the rest of the trip. All my problems were engine related. The buggies are a ton of fun but I had to face the fact that the Chinese CN250 clone was just no where near reliable enough. That was my driving reason for the engine swap. The bonus is that this thing is now a BLAST to drive. Plenty of low-end power and capable of 60mph (not that I want to go that fast in a buggy). All told, including purchasing the snowmobile, I have about $1000 in the motor swap. Well worth it IMO.
Here is the thread - enjoy
Just picked up 2 1989 Arctic Cat 340 snowmobiles. Both run great but one has bad suspension. Got the pair for $400. Going to swap the engine from the one with the bad suspension to my buggy. For simplicity I am considering abandoning reverse. I might consider trying to mate up the existing reverser if it doesn't appear to be too big of a challenge. I'll post pics as I go.
Started on the project today. Got the donor snowmobile torn down. Engine pulled. Wire harness all marked and pulled. Driven clutch and jackshaft pulled. I pulled the transmission and radiator from the buggy but figured I had enough for today so I stopped there. Will start pulling the buggy engine tomorrow.
After looking at everything I am going to mate the jackshaft to the existing reverser. Not 100 percent sure yet but one idea I had was to weld one half of a 4 bolt coupling to the jackshaft and the other half to the splined coupling that joined the cn250 the reverser.
I pulled the buggy engine this evening and set the 340 on the swing-arm. It looks like I'll have to lengthen the swing-arm a bit. I need 11 1/4" between the clutches and if I push the engine as close to the shock as I can (it is too wide to fit between the shocks) that distance puts me a little past the end of the swing-arm. Not a big deal I just wasn't sure I would have to until I set it in there. I plan on starting the fab work for the motor mounts tomorrow. I figure I'll start with the motor as far forward as I can and work back. One I get the correct distance for the clutches I can start working on connecting the jackshaft to the reverser.
I included a video of the engine running before I pulled it out of the snowmobile.
http://www.youtube.com/watch?v=7sGEO...KgX0Pe19bKAq7A ... Pe19bKAq7A
After setting the 340 in and seeing the distance I needed for the jackshaft I started cutting and fitting the new steel needed. I have the base pieces cut and positioned with clamps. Everything fits and is square. Tomorrow I'll tack the angle then pull it from the frame and weld it solid. While I'm doing that my son will un-bolt the rear of the buggy so we can grind off the paint and to make welding the "box" I built to it easier. The kid in the hoodie grinding is my son.
Started welding this evening. I've been stick welding for about 20 years. A couple months ago some low life piece of "excrement" broke into my garage. Besides stealing 2 ATVs and 3 dirt bikes they stole my 40 year old Forney welder that belonged to my grandfather. Two weeks ago I picked up a wire feed welder from Harbor Freight for $90 (sidewalk sale). I've never used one but for the money I figured why not. I bought some good wire and fired it up this evening. I am never going to stick weld again. That little 120 volt wire feed welder is awesome! I took my time and pretty quickly had the feed rate dialed in. Made nice "dime stack" welds and by the glow in the steel had good penetration. If anyone has yet to try a wire feeder it's hard to beat this one to get started with.
Swingarm extension welded in. Sat the engine back in place on the box tubing I am going to use to mount it.
Rather than weld the tubing in I am going to slot the swing arm extension and bolt the tubing to it. The will also be an another piece of box tubing for an additional reverser mount point. I'll weld in a jack screw and the enginge, jackshaft and reverser can move together to tension the chain.
It looks like I'll be able to use the stock snowmobile muffler but will have to add some pipe (it would exhaust out the bottom behind the driver - want to shoot it out the back)
Since I'm going through all this I figured I would replace the wheel bearings while I'm at it. If I mic them are they something I can find at Tractor Supply / Grainger or am I going to have to order them?
Spent some time in the shop today. I drilled and slotted the box tubing I am using to support the engine. I wanted to be certain than when I torqued down the bolts I didn't crush/deform the box tubing so I bought some steel spacers to go inside the tubing.
The slots give me plenty of slide for chain adjustment. The pics below show all the way forward then all the way back.
I drilled the holes for the engine mounts, used the snowmobile rubber mounts and bolted the engine in. I also added 2 cross braces to the box tubing (I went back and finished welding the braces after I test fit the engine)
Now I am starting to work on the jack shaft and transmission placement. I hung the jack shaft "roughly" where it is going to go. Tomorrow I'll start fabbing up bearing mount points.
TBC