I started building this thing last winter but never had a chance to start a build thread. There isn't a lot of pics as I have had phone issues and lost most of them. Got a new phone and it takes way better pics than any other phone I've had. Anyway...
Had a 87 K5 engine in a 92 frame with a bunch of 87 /88 parts attached to it. It didn't ride very well and didn't run very well either. Found some cracks in the frame and decided I needed to do something different with it. So I started pulling it apart.
2 days after setting the engine on a shelf my buddy called and said I got you a 85 quadracer 250 for cheap. Complete minus jug, head, and brake pads. Sold all the suzuki garbage I didn't need and started to get the fab gears turning.
After staring at it for a day I went and bought an 8ft chunk of 1" diameter 1/8" wall tubing to strengthen the frame with. Ended up only using about 4 feet of the tubing. Once all that was reinforced to my liking I cut the front engine mount tube just above where the exhaust port on the k5 engine wouldn't hit it. Then I cut 2 pieces of the new tubing and put a nice bend in each one to end up with a wishbone support like the bike had. Welded that in and set the engine in. Swingarm needed no modifications for the engine to fit. I was impressed with how easy it went together from there.
Once I got the engine sitting in there I had to figure out engine mounts. Lower engine mount needed moved forward half inch or so. Used 1/8" flat plate for front mounts. Drilled and bent accordingly. I made the head stay brackets the same way.
Now that the engine is in. Chain lines up perfectly. Now the fun part... How do I get the giant K5 pipe to fit
This took the longest. I wanted the pipe to fit in a way that I wouldn't burn my leg and prefer it to exit out the left side so it wouldn't cause issues if I ever wanted to put rear fenders on it. Originally I used part of the K5 stock pipe and part of a quadracer pipe. Engine would run but wouldn't rev above 3k rpm. So I started researching pipe design. Ended up buying a program for building pipes. Learned a lot playing with that program. I contacted Sanblaster to see if he could keep an eye out for a junk pipe I could cut up. He had one off his personal bike that he hooked me up with for an excellent price as always. Used most of that pipe and part of the quadracer pipe I originally used. Fabed up some exhaust mounts and fired it up. Ran good and made it up to around 8k rpms.
Now its time for a test ride... Needed some jetting done but it was pretty solid. Vibrations were horrible though. My feet and hands vibrated so much I'd lift my feet and let go of the bars. Ended up removing the head stay brackets to see if that helped any. It got rid of probably 70% of the vibrations so it never went back on.
I noticed trans oil looked grey so I decided it was time for a rebuild, crank seals and crank bearings. New OEM rings, OEM seals, and high end bearings from a driveline shop I visit frequently. Now it's running better. Re-jetted again and it's an awesome beast.