1976 XS650C Café Racer Build

[mrob24]

Evening, gents. Some more progress today while the wife is away on a hen-do. I got some parts back from powder coating today, and the lad has done a lovely job. He's a biker himself with a penchant for classics, so he gets it. Great finish, and all parts appropriately masked as requested. A stark contrast to some experiences I've had from other outfits previously.

I got back my rims, hubs, brake plate, swinging arm, and torque arm. I fitted new wheels bearings and seals front and rear, and I installed my new bronze bushings from Heiden Tuning using a very simple home made puller. It worked a treat. I test-fitted it with the thrust covers and one shim (as was fitted previously) and it feels nice at 47ft lbs. The arm falls slowly under its own weight, and there is no longer any lateral movement whatsoever.

I've also ordered a new CNC aluminium sump plate and filter kit from Rick Forte of Smedspeed, with a spin-on type paper filter. The claim is significantly improved filtration and extended crank life. Handy, given I'm about to pay through the nose for a crank rebuild...

My barrels need rebored and I need new pistons, rings etc. I came across Cruizin Image and their piston kits are incredibly affordable. It seems too good to be true, however plenty of reading on the forums provides consensus that they're decent kit.

I'm also learning (better late than never) not to throw anything away. As such, I'm growing the world's least nutritious lollipop comprising several spent bearings, races, seals etc - dead handy for driving in replacement parts, and many other jobs, too.

A few pictures of today's progress:

 

[Jim]

I came across Cruizin Image and their piston kits are incredibly affordable. It seems too good to be true, however plenty of reading on the forums provides consensus that they're decent kit.

Yes, his parts are made in Japan... not the Chinese crap.
Good quality parts. I've been more than happy with his stuff.

 

[bosco659]

Yes, his parts are made in Japan... not the Chinese crap.
Good quality parts. I've been more than happy with his stuff.

I’ll second that. Bought parts for the water Buffalo from them. Good stuff.

 

[WideAWAKE]

Yes, his parts are made in Japan... not the Chinese crap.
Good quality parts. I've been more than happy with his stuff.

I believe he is the grandson of a former Honda piston and ring supplier.

 

[JJames]

Lookin good.

 

[Wingedwheel]

can anyone advise why two of the screws that retain the camchain guide pivot arm are shouldered? Is there a a good reason not to replace those horrible screws with allen head set screws, for example?

If you’re taking about the two retaining bolts for the guide there’s not enough room behind the wishbone oiler tube for the heads to clear. That was my experience at least. I thought it would be a good idea as well that didn’t pan out.

 

[mrob24]

Evening, All, from an uncharacteristically roasting hot Scotland. Just a quick update here. Since last time, I've had my wheels rebuilt with stainless spokes further to having them powder coated gloss black, along with the hubs. I've also finished de-tabbing my frame of extraneous brackets etc. Tidied up some of the dreadful original welds while I was at it!

I've just done a mock up for the first time with the newly refurbished swinging arm, new Hagon shocks, and the wheels (today shod with Avon Roadrider MkII rubber).

It's moving forwards, albeit frustratingly slowly it feels.

Cheers,
Mark

 

[Mailman]

It’s looking good! I like the black wheels and forks.

 

[mrob24]

It’s looking good! I like the black wheels and forks.

Thanks, Mailman! I initially wanted the wheels and hubs polished, however following tens of hours of failing to achieve this myself, followed by a quote of £450 to have the work done professionally(!), I decided to go the black PC route. I'm really pleased with the result

 

[Mailman]

I just had a quick look where you live….beautiful! Wonderful landscape and history, hope to see more of it when you get on the road!

 

[Adamc]

Evening, All, from an uncharacteristically roasting hot Scotland. Just a quick update here. Since last time, I've had my wheels rebuilt with stainless spokes further to having them powder coated gloss black, along with the hubs. I've also finished de-tabbing my frame of extraneous brackets etc. Tidied up some of the dreadful original welds while I was at it!

I've just done a mock up for the first time with the newly refurbished swinging arm, new Hagon shocks, and the wheels (today shod with Avon Roadrider MkII rubber).

It's moving forwards, albeit frustratingly slowly it feels.

Cheers,
Mark

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Love the progress. Wheels look epic.

 

[mrob24]

Well, gents and ladies. I hope you've all been well. It's been a while, however things are moving again so I thought I'd post a quick update to keep myself accountable, and to lay out my plans and next steps. It's been a very busy period since I last posted: I've got a new role at work, my PhD is getting close to submission, and, most importantly of all, I became a dad for the first time to a beautiful wee boy. It goes without saying that the XS has been gathering dust. But no longer!

I've written out a detailed plan for my build. My focus at the moment is on finishing the engine rebuild. Then it'll be on to fabrication work to sort the battery and electrics tray, clock mounts, having my Tuffside café seat sorted out with the frame hoop etc.

These past couple of weeks I've been chipping away at the bottom end and the cylinder head. The cases have been cleaned up as best as I could manage at home (I decided I wasn't willing to have the crankcases blasted to mitigate against the risk of having blast media incorporated into my engine rebuild, that stuff is hellish) and I've cleaned the mating surfaces up something serious. I've ordered some Threebond 1184 to assist in sealing them shut when ready. I'm in the process of replacing all of the oil seals, and I've ordered a SmedSpeed CNC sump plate that allows for use of a modern spin-on paper filter to bypass the OE gauze filters that are as good as useless.

The cylinder head, barrels, and rocker cover were vapour blasted last year - these were relatively easy to clean out with hot, soapy water, bottle brushes, brake cleaner, and compressed air. The valve seats were in good condition, so I lapped the valves to what appears to be good effect. I then refitted the valves with new stem seals using a Silverline valve spring compressor tool from Amazon. It was less than £20 (it'll seldom be used) and did the job admirably. Those collets are fiddly buggers.

I'd planned on rebuilding the front caliper but it was absolutely knackered, in every respect. I cut my losses and bought a new one complete with pads, shims, mounting hardware etc. I'm bypassing the brake junction with a single s.s. braided line from the master cylinder directly to the caliper. I mocked the line up with a length of vinyl tubing and then custom ordered a line from Hel Performance in the UK. They make exceptionally high quality kit and it was only £45.99, including washers and two banjo bolts, one of which incorporates a hydraulic brake switch. It hasn't arrived yet.

In terms of what's next, well I'm going to reassemble the bottom end and I've farmed my barrels out to a reputable engineering outfit in Dundee who are going to precision bore them for my new 0.5mm (2nd) oversize pistons.

That's all for now. I'm excited and full of enthusiasm once again!

Cheers,
Mark

P.S. I've included a photo of my dad's 750 pre-unit Triton (currently in my garage) that he built from the ground up. It's a beautiful thing and he can make it go like stink. Clutch action is brutal, and of course it's right side upside-down shift. What a hoot!

 

[bosco659]

Well, gents and ladies. I hope you've all been well. It's been a while, however things are moving again so I thought I'd post a quick update to keep myself accountable, and to lay out my plans and next steps. It's been a very busy period since I last posted: I've got a new role at work, my PhD is getting close to submission, and, most importantly of all, I became a dad for the first time to a beautiful wee boy. It goes without saying that the XS has been gathering dust. But no longer!

I've written out a detailed plan for my build. My focus at the moment is on finishing the engine rebuild. Then it'll be on to fabrication work to sort the battery and electrics tray, clock mounts, having my Tuffside café seat sorted out with the frame hoop etc.

These past couple of weeks I've been chipping away at the bottom end and the cylinder head. The cases have been cleaned up as best as I could manage at home (I decided I wasn't willing to have the crankcases blasted to mitigate against the risk of having blast media incorporated into my engine rebuild, that stuff is hellish) and I've cleaned the mating surfaces up something serious. I've ordered some Threebond 1184 to assist in sealing them shut when ready. I'm in the process of replacing all of the oil seals, and I've ordered a SmedSpeed CNC sump plate that allows for use of a modern spin-on paper filter to bypass the OE gauze filters that are as good as useless.

The cylinder head, barrels, and rocker cover were vapour blasted last year - these were relatively easy to clean out with hot, soapy water, bottle brushes, brake cleaner, and compressed air. The valve seats were in good condition, so I lapped the valves to what appears to be good effect. I then refitted the valves with new stem seals using a Silverline valve spring compressor tool from Amazon. It was less than £20 (it'll seldom be used) and did the job admirably. Those collets are fiddly buggers.

I'd planned on rebuilding the front caliper but it was absolutely knackered, in every respect. I cut my losses and bought a new one complete with pads, shims, mounting hardware etc. I'm bypassing the brake junction with a single s.s. braided line from the master cylinder directly to the caliper. I mocked the line up with a length of vinyl tubing and then custom ordered a line from Hel Performance in the UK. They make exceptionally high quality kit and it was only £45.99, including washers and two banjo bolts, one of which incorporates a hydraulic brake switch. It hasn't arrived yet.

In terms of what's next, well I'm going to reassemble the bottom end and I've farmed my barrels out to a reputable engineering outfit in Dundee who are going to precision bore them for my new 0.5mm (2nd) oversize pistons.

That's all for now. I'm excited and full of enthusiasm once again!

Cheers,
Mark

P.S. I've included a photo of my dad's 750 pre-unit Triton (currently in my garage) that he built from the ground up. It's a beautiful thing and he can make it go like stink. Clutch action is brutal, and of course it's right side upside-down shift. What a hoot!


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Thanks for the update. Congrats on the arrival of your son and your near completion of your PHD!

That’s great you’re able to get back at the bike. I’ll watch this with interest.

 

[Raymond]

Clean working conditions, methodical, I'm completely certain you'll make a brilliant job of rebuilding the Yamaha. I'll echo @bosco659's congratulations. Love the Triton.

 

[mrob24]

Thank you for the lovely replies, gents. And for the words of encouragement regarding my build. I'm finding it all a bit nerve wracking, so they're appreciated

 

[mrob24]

I received the new sump plate modified to accept a modern paper filter. The spin-on filter is low profile (~50mm tall). I fitted the plate with the included gasket and a very thin smear of TB 1184 on the mating surfaces since this plate will no longer need removed to do oil changes. The gauze filter in the clutch cover is now obsolete, too, and will be removed in due course.

 

[Raymond]

I made the same change and have not regretted it - bought from Smedspeed. IMO modern oils really need a good fine filter to pick up all the fine particles that end up in the oil. When you change the filter, you will need a wide catch tray because the oil exits all around the filter circumference.

 

[Mailman]

I think those really are the best set up!

 

[Vincenthdfan]

I love the idea, just really paranoid about a speed bump, or around here in the Northwest, tree roots pushing pavement up into a large bump (yes, I've struck one before with my undercarriage).

 

[Raymond]

. . .yes, I've struck one before with my undercarriage.

Sounds very painful.