1972 Honda CB175 Super Sport restoration

[911hillclimber]

Wife said the fence can wait a few days. She loves F1, so is glued to the screen....

Grit blasting.
Hate the job. Have a small cabinet, a small compressor and some enthusiasm.
Tried to blast the centre stand of the tar like black paint hand brushed on by the previous owner.
No chance. God knows what he used, but I don't. Paint stripper does soften it.
Gave that up asap and took a big box of bits to Redditch this morning for them to have all the fun, sod the cost.

Bribed Mrs Hillclimber with a new top and new shoes and a ride out in the Boxster.

Blasted the crankcases. That worked much better, and after today's detailing and flush and scrape and repeat x 3 they will be etch primed tomorrow during the F1 race.

The grit is out of all the castings so a big agitated flush in cellulose thinners and then panel wipe wash and mask the gasket faces and those will be ready for primer + Hammerite silver.
Ordered all the seals (11) and a few rubber bits for the usual £70!
Honda Bond for the crankcase seal on order, bolts on order, and probably more I can't remember.

Typical Honda restoration! £££££££££ all the way.

Lost one of the 6mm pins that locate the outer race of the crankshaft roller main bearings (4 bearing crank) so have to make one tomorrow too.

Fence comes next, then engine bottom end build next weekend. The engine will be done quickly, the frame not quite so quick!

[911hillclimber]

Fence actually done, about 1 million points in the bank. Took 1.5 days and 499 screws (I have just one left over)

No splinters remarkably, wet, and smell of tantalised wood and ache in a few places, but this hard graft is not really my bag, give me a roller crank any day.

Time to get back on the bike later this week with the UPOL etch primer all done on the crankcase halves, new bolts here, awaiting the seals from CMSL and a nice tube of real Honda case sealer.
Tried to get some Hammerite smooth silver gloss, but nobody has any! Supplies almost dried up but on order.

The WEMOTO cb 125 front mud guard arrived today, looks good for £38 delivered and fits a treat, esp with the narrow front tyre this bike has.
Chrome box full and ready to go to Brum next week so all the planets are lining up nicely.

Plan is to get the engine done unless I find the previous owner's have done a poor job on the valves etc.
Can't stand to trust in the work done, so going to strip it and redo the valves etc.

The small bearing location dowel that I lost and remade (thanks for the DDK'r who offered to send me one) the wife found outside the garage in the garden!

HOW did she see that? (6mm dia x 12mm long)
I searched for ages in the same spot. Amazing she know what it was, I must talk in my sleep...

[911hillclimber]

Up and Down day on the bike.
Cases painted silver, look good. Job done.
Started on the other engine castings, lot to do I thought, I was not wrong.

Barrel block cleaned up well, one bore could be nicer, but will fly with it.
Came to the head...
I had decided to strip the re-built head after seeing the previous attempt at restoration on the bike. Turned out to be a wise move.
Took one exhaust valve out and it was stuck in the guide. Drifted it out....a vice burr was evident on the area just below the collet grove, probably a firm grip in a vice while de-carbing the head.
No valve seal.
Put the head right side up and flooded the area with the double valve springs with WD40 and it came past the heads of the other 3 valves!

So, full-on head job. Could do with a very light skim too as there is some local pitting of the casting where the gasket would seal.
Have a spare head (!) and contemplating using it as the head face is much nicer.

Will sleep on it.
Hoping to get the frame and other frame parts from Redditch Shot Blasting tomorrow, broke their delivery promise today..

[911hillclimber]

Got the frame etc back today, what value for £86!
Bit of holed rust in the rear swing arm, just like the other one I did a few years back.
No probs, bit of welding and it's done.

Beautiful day, so mounted the frame on the engine stand so like a rotisery and painted the lot in UPOL etc primer, nearly 2 tins.
Hope to get in black over the weekend.

The original ....rebuilt.....head is toast. So much corrosion in all the wrong places.
I have a spare head all stripped and in much better condition, just needs a very deep clean.

Seals arrived from CMSL, so have everything I need to build the bottom of the engine, generator, clutch etc and cylinder block.
Need some parts for the head, and awaiting the motorcycle type valve spring compressor to arrive.

Garage is a mess of parts, dirt and grime, got to get the motor done asap so I can get on with the rest.

[Hugo 356]

Amazing progress, you've only had it 2 1/2 weeks!

[911hillclimber]

Kripes!
Someone has said something!!
Thought Iwas talking to my self Hugo.
The hard bit is just starting.

[911hillclimber]

Glorious afternoon, so dropped 3 rattle cans of gloss black over mostly chassis/frame parts, 2 coats, 15 mins between them. Everything went well until a swarm of small flies inveaded the frame. Managed to wet flat the tubes that are on show and re-blacked them, came out well.

Removed the rusty patches in the rear swing arm and mig welded repairs, etch primer and black gloss. My favorite method is to drill a big hole at the focal spot (hole) of the rust and drill until thick fresh steel is found, knock gently the hole to a depression, about 2 mm deep. Make some steel discs to suit the depression. Weld around the disc and the weld is almost flush. As this area will not be visible I left the welds as they finished.

Between the paint booth (under the awning bottom of the garden) had a good go at the cylinder heads.

Fortunately to say the very least, my motorcycle size valve spring compressor for £10.75 turned up. What a tool!
Utterly fantastic, and all the valves were out in under 5 mins, superb.
The collets are tiny and of course many seals were simply not fitted on the re-build, so a small order again to CMSL in the Netherlands for seals and studs.

Very happy with progress so far but a lot of detailing to go yet.

Plan for the coming week is to build the bottom of the engine ready for the head, deliver the parts for chrome and more silver painting between a mini road outing in the old 911 and being taken shopping to Shrewsbury.

[smallspeed]

I might be teaching my grandmother to suck eggs here, in which case I apologise, but the first small Honda Twin a friend rebuilt (CB160) he had some issues on reassembly with the collets / spring retainers not quite sitting right. I've "fixed" this on old Mini's, VW's and just about every other head I've rebuilt since it was pointed out to me as a wet-behind-the-ears 15yr old. At the time I thought the engine builders were taking time out to teach me something but infact matching and sanding collets became 50% of my work for the 3mo which followed!

Its relatively easy to diagnose and fix. Basically if you put two collets together in your fingers around the valve stem, the collets touch together at the split-line, but the stem is slightly loose in the middle. You can sort this by measuring the distance from the tangent of the outside of the collet, and the flat faces, then pairing them up to make as many good pairs as possible. Any remaining pairs which are still slightly oversize, just slowly grind the flat faces down a bit so they are fully seated in the grooves of the valve stems with a small amount of clearance between each other. This ensures they have full "grip" on the valve stem - terrible explanation but hopefully it makes some sense with the picture below..

Might be worth checking yours as you go / before reassembly incase you have a similar situation; from memory we were able to get them all to (very little) clearance by only reworking a couple on that engine

Viewed from above..
Yellow and Green = collets
Blue = valve stem

[911hillclimber]

Thanks!
I do the 'gap' test before assembly on the valve before installation to be sure.
At 10,000 rpm this engine is designed to be reaching for the red line, big bang is a valve drops and worse...

Spent ages yesterday and part of today cleaning, etch primer and painting lots of parts, maybe 20 so far and still not finished. Bit of a bore, bet getting there.

As an aside, started to fine polish the two engine covers that would have come on the bike to a mirror finish.
Harder than it first seems. Tempted to ask the plater to do the two on Thursday when the parts are delivered to them.

Same goes for the front forks lower axle mounting tubes, cast aluminium and scared by weather and poor spanner work since 1972.

Tempted to get them reasonable and silver paint them.

Last bike took ages to polish the two.
£57 had bought a small packet of valve seals for the engine!

[jjeffries]

Another lovely project to follow along. I worked for American Honda Motor Co., Inc as a young guy from 90 to 97, a time when the epic spirit of Soichiro Honda was still relatively alive in the products, both cars and bikes, and in how we all approached our business each day. According to friends still there, that spirit is now only a thing of memories.

I may have said this during the infamous French motorized bicycle project, but I'm surprised you don't use more pro-grade paints ... activated/urethane, etc, shot out of a small gravity feed gun. Maybe the isocyanates are a worry, or the hassle of gun cleaning? Not a dig, just an observation.

Thanks for documenting and sharing,
John

[911hillclimber]

Hello John, thanks for the thoughts.
I just keep things simple, but it seems to work, but L never keep them to check the robustness of my efforts.
Plan to keep and ride this one, but wife not happy.

Have several other things to do now, Motorsport is waking up so I'm part of the Covid 19 squad, off to the track in Wales in 5 mins.

Hope to build the bottom end this weekend.

Mr Honda was a true great man of his time, do people like him exist today?

[smallspeed]

that spirit is now only a thing of memories

..and wheeled out for tv adverts

I had planned on having my CB project done around the same time as mr hillclimbers for a honda-twin ride out, however he's overtaken me and streaked off into the distance already - benefits of being retired I guess

[911hillclimber]

Stop slackin' and get it done!

Lapped the valves in the 'new' head this afternoon, tested with thinners in the chamber with a light pressure on the valve heads and the plug in. No leaks.
All the seals arrived from CMSL today too so hope to get a lot done this weekend.

In contrast, took the box of bits to the chrome platers in Brum.
Having fought Birmingham and Dudley and possibly got a speeding ticket (about 33 in a 30) sort of found the platers...
Decided not to leave it there. Not the most inspiring place.

Looking for some place with an estimate south of £1000.

Day out tomorrow with the Boss in the 911 into the Cotswolds to lift my spirits. The 911 never fails to do that.
So pleased to have the pics of my first Honda resto to hand!

[911hillclimber]

Saturday morning: James Martin cooking.
Sat afternoon: F1 Quali

Perfect day for the garage! Wife loves the above.

Engine build-up started in earnest.

After a fiddle the gear selector system was in with new seals. Nearly made a real mistake but corrected. It would have been a total strip-down if I had missed it. Gears dropped in, roller crank fell in.
These little Honda Twins are like watches.
Popped the lower case over the top case and bonded using real Honda Bond. It seems very familiar stuff, used Loctite Porsche case sealant last time.
The gear shifting system next, what a game, even warns you in the Haynes book! Got there in the end, what a faff, took ages.

I pity the poor Japanese souls who did late back in the day.

Chain sprocket on, and clutch basket too. The basket has an eccentric lob on the back side that moves a plunger in the oil pump so the lubrication is pressurised, miniature and exquisite.

That little lot cost 5 hours!

Found a past gasket set I had spare for some reason which has all the cylinder head seals in it that I've just bought from CMSL...

On that note I called it a day.
Hope to get much farther tomorrow while Lewis does his stuff.

[Bruce M]

That last photo looked familiar.... ThisOldTony video yesterday on clutch packs looked exactly the same.