1974 TX650A Restoration Project

SomervilleXS650

XS650 Addict
XS650.com Supporter
Messages
245
Reaction score
984
Points
93
Location
Somerville, MA, USA
Hey everyone.
This is my first post even though I have been lurking on this forum for a couple years now. It's been an absolutely incredible resource and as someone relatively new to motorcycling, I can't imagine how else I could have become so familiar so with my 74 TX650A so quickly.

I purchased the bike in 2018 from a local guy who sniffs out barn finds and flips them on EBay. Had about 21k miles on it, and had been sitting idle for the last 15 years or so. The seller got it started easily, but the front brake was shot, no starter and really needed a going through. Had clearly been dropped, and at some point some genius had just cut all the handlebar wires and elec taped back together (like 2 inches away from all the bullet connectors in the headlight). That first year I fixed the brake, and sorted out lots of the electrical gremlins, and learned a lot about basic tuning and simple maintenance. I had some charging issues and got myself stranded a couple of times which prompted me to buy and install the HHB PMA/CDI system in the hopes of improving the reliability. I managed to get the bike running well and had a nice couple months of riding before the weather started to turn in the fall of 2019.

At this point, I needed to winter the bike, and had a decision to make. I live in the city, so don't have a garage, so I could either pay for storage (which is fine) or I could take the opportunity to fully go through the bike and give it a proper restoration. I've never been one to shy away from a project so I said screw it, and went for it. I broke it down and lugged it into my basement workshop and got to work....

I am not a mechanic, and before this bike, hadn't done any mechanical work to speak in about 20 years since wrenching on some classic cars in high school. Goal of this thread is to try to contribute my own experience in the hopes it helps someone the way all of your posts helped me.

So with that....here are a couple of the 'before' pics from the original seller when I bought it and a third of the last day I was riding in October 2019 before the project began.... and away we go....
s-l1600 (1).jpg
s-l1600 (3).jpg

47C3F510-7111-492C-AEA5-AD3C5CCFFF05.jpeg
 
The bike was running reasonably well when I completely broke it down and lugged it into my basement in parts. I was starting to get some oil leaks around the clutch pushrod seal and maybe also the main crank seal, although I wasn't 100%. What became apparent when pulling it apart was how grimy the underside and engine were. I had cleaned things up reasonably well on the bike, as shown in the last pic of my first post (at least visible parts), but the underside of the engine, swingarm, mufflers and brackets had what I imagine was "authentic" 1970s grime. You can see some of this in the engine pics.
E9526C31-2CBC-4B3E-8F47-A1D2B38AAFBF.jpeg

9129D3F8-4CA3-41B3-919F-0590EC05AC02.jpeg

I figured since I had the motor out of the frame, and since there was no report from the seller that any overhaul had been done, I thought I would do a top-end rebuild and see how the cam/rockers/valves/pistons looked and give a good clean. Everything came apart pretty easily, which I was very happy to find. I was also happy to see that the notoriously 'disintegratable' cam chain guide was more or less intact. My goal, aside from just cleaning the holy hell out of everything, was to at least replace the rings and possibly anything else in the valve assembly that looked worn or out of spec.
F279E7B3-41CD-4C50-B5E3-85662099A855.jpeg
993499D6-0189-456A-81F2-94B142F31014.jpeg
27A2CFB0-B6C7-4282-BDA2-96F3850B71BD.jpeg
0D5F1997-F5D5-4ED3-B104-20A30CB98BBA.jpeg
92E5B6E6-1382-4330-93C4-4C7E4C43A923.jpeg
3E12B977-5C14-4A4C-8877-010ED4428D2B.jpeg
C0E37D46-E8E0-4B6D-AC12-049A2B024CFA.jpeg

4376F940-686D-4AEE-9DF9-98B2ADA34689.jpeg
 
Last edited:
Welcome Summerville - from Canada’s sunny southern coast inWindsor, Ontario!

I really like your ‘74 - you don’t see too many with the original exhaust and tins. I see that you’ve dug right in and all I can say is that the effort will pay off. I suggest you check out Jim’s engine top end thread. It is the gold standard on rebuilding an XS650 engine.
Cheers and post lots of photos.
Pete
 
Thanks guys! So many familiar faces, I'm getting star struck, hahaha.

Yes, was pretty happy with cam and followers, I had seen lots of pics of lobe wear or wear on the follower faces. I have a digital set of verniers and the cam looked to be in spec as best as I could measure anyways. One thing I've learned is that no amount of reading or pictures can replace the first hand experience required for the "feel" for fussy measurements. But all in all, I decided to just clean and keep everything in the top end (except the cam chain, of course).

And regarding Jim's post......hahaha yeah, I'm familiar. I'm not a mechanic, but I AM an engineer, so what I lack in experience I try to make up for with neurotic preparation.
2C9BE71C-7EC8-446F-BC10-C3FCFC6DE67B.jpeg
 
And regarding Jim's post......hahaha yeah, I'm familiar. I'm not a mechanic, but I AM an engineer, so what I lack in experience I try to make up for with neurotic preparation.

HEY - I represent that remark!! ;)

hehehehe

Dr. Pete, P.Eng.
 
Before I get too far into the motor, I should probably sidetrack a little and talk about a tool I built that will be a central theme of this project....

Over the 18 months or so from when I first got my TX to when I decided to go ahead with the restoration, you might say I contracted the condition we all know as 'bike fever'.... So in the winter of 2018/2019 a buddy and I had the idea to try to build a couple of custom cafe/tracker/brat hybrid-what-have-yous to putter around town as a fun project (a lot of the details were clearly TBD). We found a really rough pair of '72 Honda 350's (CB and a CL) as platform bikes. Fast forward, and let's just say the project was sidetracked by my TX over the last 6-8 months and the fate is probably up in the air a bit. I bring it because as part of that project, I built a homemade vapor blasting (honing?) unit that I ended up using quite a bit on all kinds of components on this build, so I figured I'd talk about that a little in case of interest.

I utilized a cheapo Central Machinery sandblast cabinet from Harbor Freight. This thing was like $99 USD with a coupon. I coated the entire interior with clear Flex Seal (as seen on TV!!) to ensure the seams were water-tight. I changed out the bulkhead fittings in the rear for the slurry/air inlet to use some water-tight grommeted fittings. I had access to an air-actuated diaphragm transfer pump which does the trick perfectly for the slurry transfer. The recirculation vessel is simply a 5 gallon bucket with a drill-powered agitator in it. The transfer pump pumps the slurry into the gun, the air-feed to the gun accelerates the slurry, and it gently cleans/peens the surfaces leaving a rather handsome satin-y finish. While a little clumsy to set up and get the hang of, I would say it ended up being quite an invaluable resource for me. I would say your results may vary, because two central features that were key was 1) I had access to an old pump that was not being used through my work (probably a couple hundred bucks from McMaster) and 2) I knew I would be utilizing this in my office workshop on the weekend to have access to the compressed air I would need. Both of those elements were key for me, especially the air, as our house compressor is a sizeable unit that I would not be able to mimic in my basement workshop. I also figured, since I wasn't building this for 'forever' use in my home shop, that if this thing only lasted for one build, I would be ok with that (talking most notably about the cabinet here). I ordered the peripherals from Amazon, and aside from basic tubing, barb fittings, etc to make all the plumbing work, the key components are probably the media and the gun. For these reasons I would say the DIY approach was probably more cost effective for me, but if I didn't have those key elements in my favor, the entry level unit from VHT may just as well been the better option.

Media:
https://www.amazon.com/gp/product/B07TK1WLDF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Blast gun:
https://www.amazon.com/gp/product/B07BSJH6SJ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

You can see a couple pics below and a vid of it in action, plus a couple half-done components from the Honda that shows before and after. I'm going to reference it quite a bit, so now you can at least see what I'm talking about.
IMG_0059.jpg
IMG_0063.jpg
IMG_0066.jpg
IMG_0109.jpg
IMG_0110.jpg
IMG_0241.jpg


[Edit] - YouTube channel sorted out. (Rather boring) video here:
In the future I will make sure to stick to landscape mode!
 
Last edited:
You can see a couple pics below and a vid of it in action, plus a couple half-done components from the Honda that shows before and after. I'm going to reference it quite a bit, so now you can at least see what I'm talking about.

Where's the pics?
 
Where's the pics?

They're up now! Although still trying to figure out the video.
To that point.... I'm still trying to figure out the easiest way to get all these pics off my phone and uploaded after writing these posts on my laptop. Feeling a little clumsy. Any tips from the pros here would be appreciated.
 
Somerville,
Welcome to the forum, I’m looking forward to following along on this bike. That’s a very nice bike you have going there, I always appreciate a stock restoration and that specific model year is one we don’t see a lot of. I can see right off that you are a kindred spirit, your level of organization and attention to detail caught my eye, as well as your shop set up. Good luck with your build and thanks in advance for the photos and the well written details of your experience. ( gotta love engineers! ;) Engineers rule the world, or so Pete says! )

By the way the best way to handle videos is to upload them to YouTube then post a link to it in your posting.

-Bob
 
Last edited:
Thanks fellas. Read a lot of your posts Bob, so thanks for the kind words. Looking forward to sharing my journey with so many of the folks that helped to create it (even if they didn't even realize it at the time!).

Impressive bit of kit - good results from the blasting.

Thanks Ray!....I'll post some of the ones of my TX soon....it works surprisingly well, I have to say.
 
Last edited:
They're up now! Although still trying to figure out the video.
To that point.... I'm still trying to figure out the easiest way to get all these pics off my phone and uploaded after writing these posts on my laptop. Feeling a little clumsy. Any tips from the pros here would be appreciated.
I use Google Photos and linked my phone to it. Take a pic and about a min. later I can bring it up in my browser... as if by magic. :rolleyes:

Videos... yeah what Bob said. With the video on Youtube... click the Share button. That saves it to the clipboard. Then click the Media button on your post. That brings up a box to paste the youtube link into and Bob's your uncle.

Untitled.png


Untitled.png
 
Somerville (sorry about the misspelling earlier): since you are upgrading the Harbor Fright ;) blasting cabinet, you might want to check out an excellent YouTube channel called Keith Rucker -Vintage Machine.org.

Mr Rucker does really nice machine shop work on elderly equipment but recently, he did an upgrade on that same or a similar HF cabinet and made substantial improvements for not too much money. If you search his channel you’ll find the episode. In fact, here it is!

 
Thanks guys! I've been sorting out my Google Photos sync so I think I've got that sorted out, and I just started a YouTube channel to use for vids and added one for the vapor blaster.

Pete - yes, I think I ran across that vid (although not his other videos, which sound cool!), and I've seen some of the other ones out there on HF cabinet upgrades. There's one guy in particular who converted a sandblast cabinet into a wet cabinet and is trying to sell the plans, haha. Can't blame him for trying I suppose. Mine is pretty simple stuff but it was mostly all the little tweaks to get it operating smoothly. I have NO hopes of this thing not rusting out in the next year, but it did the job, and was certainly more convenient and cheaper than sending out.
 
Hey there 5T!

I'm sure there are a lot of folks who can speak much more intelligently than I can about the differences, but the main points of differentiation are the use of the liquid carrier, as well as the size of the media. The glass bead used in vapor blasting is much smaller than 'standard' glass bead which makes it a gentler process. It's dustless and can run at lower pressures. The water can act to lubricate and cushion the media to a certain extent, so there's less chance of mucking up critical dimensions on things like bearing journals. I've also read that at the microscopic level there's a peening effect that can happen that will actually help to keep components cleaner but I'm curious as to how real that is. I don't have a tremendous amount of experience with dry blasting so I can't give an apples to apples commentary on dry glass bead versus vapor blasting, but seeing some of the videos on before/after and knowing I had some pretty cruddy parts, the VB approach seemed like something worth checking out.

Some additional points here: (written by a company that sells Vapor Blasting/Honing equipment, so take that for what it's worth haha).
https://vaporhoningtechnologies.com/advantages-of-wet-blasting/
 
Back to the top end...

I pulled the pistons off and cleaned up a whole ton of carbon with a bit of degreaser and then some Autosol, just to have a look at what I was dealing with. Thanks to many threads on the subject, the .955 on the faces seemed to tell me these were the factory pistons and they looked to be in good shape from what I could see.
IMG_1673.jpg
IMG_1685.jpg
IMG_1676.jpg

The jug visually looked pretty good as well, with no apparent scoring. I never actually measured the compression before I took it apart (dumb...), but the bike was running pretty well, so I didn't have any specific reason to think anything was out of sorts. I decided to keep the original pistons, replace the rings, hone the jug and leave it at that.
IMG_1671.jpg

IMG_1709.jpg


Here are some other pics of the cam chain tensioner, valves, inside of the head and valve seats:
IMG_1703.jpg

IMG_1733.jpg

IMG_1723.jpg
IMG_1724.jpg
IMG_1726.jpg


So again.....my inexperienced eye is looking for pitting and wear on the seats, but hard to know exactly how much is too much. The valves looked straight, and didn't have any pits or anything that looked egregiously horrible where they seat. At this point, I figured I'd clean the head up, give it a once over and try lapping the valves by hand and seeing where that landed me.
 
Your parts all look in remarkably good shape. Even your dirty pistons seem to indicate the rings were sealing well. There is no staining on their sides. That occurs when compression leaks by the rings and burns the oil on the sides of the piston. You usually find some but yours has virtually none. I would check your original ring end gaps and if still in spec, you could probably just re-use them, and no honing needed either.

Yes, hand lap the valves in to re-seal them. All those black specs you see on the seats now are pits or the start of them. To clean the carbon off the combustion chamber and out of the exhaust ports, plain old paint stripper works well. It will literally melt the carbon away and greatly reduce the amount of scraping needed. And it should eliminate the need for any hard scraping as the carbon will be greatly softened.
 
Back
Top