1973 Suzuki TM250K
I picked up this very sad TM250K to be my first vintage MX bike project. Considering the condition, many would say it isn't worth it, but I like a challenge and hate to see any classics go down. Besides, if I can get this thing back in race condition, I should be able to handle anything, right?
Like the rest of the bike the engine was in pretty bad shape. While it turned over and had decent compression, disassembly showed a lot of issues:
- The main bearings and lower connecting rod bearing were shot.
- The frame mounts had worn a hole in the top of the cases allowing mud in; a result of poor maintenance – loose mounts – no doubt.
- Cylinder and piston were border line.
I had the cylinder bored and ordered a new Wiseco kit. I found a NOS crank and ordered new bearings. One of the head studs was sticking out a little further than the rest. Investigation showed the stud was stripped in the cylinder. I had a Time-Sert thread repair kit from another project, so I used it to repair the threads and then ordered all new studs.
To repair the cases, I built up the mount points with a TIG welder, and then machined them. It wasn’t necessarily the prettiest repair but it worked.
The oil slinger was cracked. I originally repaired it with some welds, but then found a NOS one on eBay.
The reassembly went well and I think she looks pretty good.
The frame had several issues that needed to be addressed. It had worn and broken motor mounts, some rust pitting and a crack under in one of the top subframe bars.
I cleaned up the frame with sandblasting, wire wheels and an angle grinder. I welded the cracks, pits and broken motor mounts. I also brazed on some washers to improve the strength of the mounts.
The subframe also has a slight bend upward, likely from a hard rear ditching. I haven't determined the best method to straighten this yet.
Rusty spokes, pitted and cracked rims, rotten tires - basically shot. The rear rim could be salvaged but the front rim had several cracks and some bad corrosion pitting. I decided to replace them and ordered new Tusk rims. Unfortunately, I prematurely ordered spokes and they turned out to be the incorrect length for the new rims. It turned out the rear spoke kit was missing a spoke anyway, so I was able to return it. I'm waiting on a used set of forks from a '74 model which will include the front hub. I suspect the front spokes will be incorrect as well.
I contacted Buchanan's spokes via email, but didn't recieve a reply. Once I get the new front hub, I call them to see if they can supply the spokes I need.