1973 Yamaha TX650
Purchase Date: May 2021
Well, this is a pile of bones.
A friend of mine from work had this pre-XS650 - TX650 sitting in his garage since the 80's. I have no idea why it was disassembled, but it was and I ended up with it for free. The Yamaha lived it's life running hard in the 70's and 80's in Berkeley and surrounding areas. 20-some thousand miles of starts and stops and who knows what. This bike was a runner. Two rusty tanks and most of the bike is there, of course not everything - that would be too easy. Nothing is "free" or "easy". At least for me it hasn't been. |
The 1973 Yamaha TX650 is the predecessor to the XS 650 series. These earlier models have hotter cams, simple chain tensioner designs and different pistons and along with a bunch of other small differences. Overall, they're the same bike - to me at least. The TX was produced in '73 and '74 before the name change. The simple, parallel cylinder air cooled twin has a single overhead cam. Wet sump style oil transfer with wet clutch plates. The bike makes 53 hp at 7200 rpm and just shy of 40 lbs/ft of torque @ 6800 rpm. A five speed transmission drives the final chain drive to the wheel. Drum brake equipped rear wheel, single disk brake up front. The Yamaha has a 3.3 gallon gas tank and an average fuel consumption of 47 mpg. Top speed is 115 mph and dry weight is 420 lbs.
What direction to go? - that is the question. The bike is too far gone for a full restore. I'm not really into flat-trackers which is a popular direction. I'm thinking a chopper. This is another popular direction and there are lots of great ideas to leverage from the internet. From where I'm sitting, I'll have to get this engine running before doing anything else.
October: 2021
Engine: After doing a costing estimate on the time and materials for making an engine stand myself, I decided on purchasing a TC Bros. stand. It works well and fits the engine fine after a little bit of boring out one of the mounting holes.
On to the engine itself... I stripped down the top end finding fairly clean parts with lots of red gasket maker all over the place and one stuck valve. Armed with a new gasket kit along with some smalls from mikesxs and new std size rings from scramblercycle I rebuilt the top end of the Yamaha. At this time, I did not venture into the bottom end. I have to see if this thing runs before doing much else. The rebuild includes the new piston rings, honing, valves re-lapped, springs and valves checked to spec., everything to spec.. |
January 2022
Engine: The engine is fully closed up. Timing and points set to spec. Engine is ready to be installed into the frame (pic).
Engine is back into the frame. Time to get this thing moderately assembled and fired up. I don't have a title for the motorcycle yet, I plan on getting it to a modest rolling motorcycle-ish stage and take a trip to the CA DMV.
June 2022
Carburetors: I rebuilt the carbs a few months back, standard settings for now. I'll probably have to open the jets up a bit after adding aftermarket pod filters. 1st things first, need to get this thing running.
Shifter Spring: Someone (aka., me) accidentally bumped this out of neutral with the shifter case off and the shifter spring jumped out of location. I successfully disassembled the clutch housing + basket and thrust washers, etc... all to get to the shifter spring. Back in location and the internals look good, I guess it wasn't such a bad thing to open the right case for peace of mind with the internals.
Neck Bearings: The neck bearings that came with the bike were shot, rust and flat spots. I got some stainless steel balls the same diameter and installed. I'm not ready to spend the money on a set of taper roller bearings just yet.
Shifter Spring: Someone (aka., me) accidentally bumped this out of neutral with the shifter case off and the shifter spring jumped out of location. I successfully disassembled the clutch housing + basket and thrust washers, etc... all to get to the shifter spring. Back in location and the internals look good, I guess it wasn't such a bad thing to open the right case for peace of mind with the internals.
Neck Bearings: The neck bearings that came with the bike were shot, rust and flat spots. I got some stainless steel balls the same diameter and installed. I'm not ready to spend the money on a set of taper roller bearings just yet.
I don't have time these days to get back to working on this. The bike is currently together, awaiting a trial start. That's where I stopped. Hopefully I'll get back to this soon. Probably fall, when some of the other "running" motorcycles take a rest.
Photos and details of the TX will be added as the project matures.