1972 Honda CB175 Super Sport restoration

[911hillclimber]

After reading a comment on the Classic Motorcycle forum, I'm going to give the carb's pilot drillings another go to see if I can get the running keener.

There is a short drilling in the circuit that is sealed by 2 ball bearings, probably 1.5mm max diameter and I can't get a wire to it, so another soak in a real US cleaner down at Villiers Services I think if I can get to them tomorrow morning.
They do pro carb and engine rebuilds on older engines so know their stuff.
The US cleaner I've used does not seem to be effective so I hope theirs is more up to the job.

Doubt they can get the balls out and replace, so US cleaning it the only chance I have.

[911hillclimber]

The carbs could not be cleaner!
Brake cleaner shoots through all the passages and jets, and to top it off they spent time in the US cleaner at Villiers Services this morning.

Bike running on equal heat both sides and a low tickover. I don't trust the tacho's accuracy.
Good response to the twist grip so leaving it all at that.

The air screws STILL do nothing around the 0.5 turn to 2.5 turns to the tick over.

The starter chain/sprags etc make an awful din now but sometime hook up and spin the engine well to start, so taken the generator cover.case off.

The chain is very slack, but i doubt it would go on if I took a link out.
Are they supposed to look 'too slack'?
The lower half is nearly touching the engine case.

I have new sprags etc coming, but maybe I should bite the bullet and fit a new chain while in there.

Oil came out black, so discarded.

Last snag to fix is the leaking lh side fork.
Fork oil keeps on coming out albeit very slowly. Seems to be coming from where the front mudguard mounts. Maybe the fastener hole has broke into the lower fork casting?

Anyhow, still progressing.

[911hillclimber]

A few steps back and a few smaller steps forwards today. Funny how some days you get in the mood to get the jobs done.

Still waiting for parts from D Silver for the starter clutch, but found my spare starter motor which has a pinion spline shaft that is not wobbling all over the place, so a silver paint job, back on tomorrow.
Kept on seeing the oil weep from the engine top 'rocker cover', been weeping since I started the engine, one of the green gaskets that seem poor at their prime task, but found a new black one so the top mounting came off and the gasket replaced.
Moved the conderser from the one cylinder head domed nut to the mounting bolt so getting a good torque-down of the head to 14 lbft, nice solid click on all 8 and a guess on the m6 bolt.

Lack of parts stopped play, so did some gardening to impress the Wife.

That one fork is still weeping mind...

[911hillclimber]

The starter sounded terrible (electric) so replaced the motor, replaced the rollers/caps and springs, didn't replace the chain (mistake I think) and it sounds as awful now as it did before.
Parts were delayed as the 'in-stock' cover gasket was in fact in stock in the USA, but parts arrived today.

Putting that snag to one side, started the engine.
Would not start, churned over and over and then realised I had left the plug caps off....day not going well.

Running now but really not well. LH side hot, smoking rich and rusty water droplets profusely coming out the back, RH side cold. Here we go again!

Cold rh side carb then really flooded!.
Removed that carb and checked the float level, 21mm with the float just touching the sprung tip.
Decided to check the needle to the brass seat and that seals, so did a radical thing and set the float to 21 with the car upside down, ie the needle seated by the weight of the float.

Put it all back together and no flooding, however stone cold when running (LH side hot and smoking rich) and the speed adj screw does nothing, understandable as no combustion on the RH side...

It's 4.00 o'clock in the afternoon, just had a cup of tea and put the bike into the garage and tomorrow is another day.
Will this bike ever come into tune?

[911hillclimber]

Made some good progress over the last 2 days.

Cured the carb flooding issue. The carbs have a float with a brass tang in the centre which bears down on the needle valve. I found the angle was at 45 deg and not true to the needle valve causing a side load on the needle and jamming open, hence the flood of fuel.
Tick off the List.
Got the engine running better, far better with oh-so-small incremental movements of the tick over screw and the pilot air/fuel ratio screw, talk about a tight rope tuning. These carbs are infamous for this quirk.
Tick off the List.
Fixed the loose headlamp mountings by re-assembling the top fork handle bar yoke and all snugged-down nice and tight. No headlanp shakes now.
Tick off the List.
Trial and fitted the mega expensive side panels except they didn't fit at first. Numpty here had placed the tool box in the wrong pair of mounting holes in the chassis frame, what a faff to move and re-fit! All on now.
Tick off the List.
Fuel tank back on and fully coupled up. Pesky balance tube connecting the left and right sides of the tank fought me all the way, but lost.
Tick off the List.
Fitted the new seat from Taiwan, what a bargain for £100 delivered, resplendent with the 'HONDA' script of course. Perfect fit, fabulous.
Tick off the List.
Fitted the aluminium number plate at long last, really looks the Classic it is.

Nearly completed now, waiting for a new expensive starter chain to arrive and the bike can come down off the stand although it is very convenient on the stand while I prepare for some work on the Lola and the 911.
3 weeks late on the project!

[KS]

Bravo! That looks wonderful!

[AndrewSlater]

Excellent work - looking great!

[911hillclimber]

Thank you both.
Taken too long held up for parts, my last order to fix (I hope) the noisy starter drive has to wing it's way from the USA, so another week gone by.

But, all but done.

This has been far easier than the gold one I did 5 years ago as it has been a re-build rather than striving for 100 point restoration and the costs have been far lower as a result and less delays.

Will have a rest soon, and then decide what to do next, probably going to fit an electric motor to my 1952 Peugeot BIMA which hopefully will be tricky and a bit of a challenge unless I can fit a 50cc 4 stroke into the frame, far far harder than it may sound.

I have the BIMA all ready 'safe' and registered so would be ahead of the game, and keeping the oily-rag look too.

Of course there are the 911 and the Lola to tend to and the garden.....and the hall staircase (yuk, wood involved) and I have a few guitar projects too, so lots for this winter.

[911hillclimber]

The new starter chain came today, now much improved.

The carbs that are 'sort of good enough' are bugging me, and thinking of adapting some Chinese Dellorto knock-offs for the bike to see if this improves things.
They are very cheap, and I already have one from my French Terrot escapade so know the quality which is remarkably high, and only £11 delivered to my door.
Yes, £11 each.
Cheap lock-down experiment that might work.
You can get a range of jets for tuning them for £9...

[911hillclimber]

2 new Chinese/Dellorto/Keihin carbs on order, £21.
The stock jets etc all fit this copy carb, and even the choke actuation mechanism swops over.

They are only available to one hand, so will need a long thin screwdriver to tweak the adjustors.
There will be several compromises here, but having the stock jets in place could mean I can get away with it.

The air screws are solid, no drillings (ref Sprint's post on Richard's thread about early carbs using undrilled screws) but the stock ones fit!
This should give me some variables to try.
I have a set of fine drills, 0.3mm to 1.5mm, all new, and I've compared the copy jets to the stock jet drillings and they all match, exactly the same sizes, BUT the stock jets have more cross drillings than the copy ones have.
I'll try the stock jets in the copy bodies first running the copy slides but if I can, the stock needles.

Looking forward to this experiment.

The idea of this rebuild was to have a few challenges to overcome so this is going to be good to see if such a matching of parts can work. It might
cost me a bit of power, the 'throat' of the car is 1mm smaller than stock, 17mm plays 18mm.

Pondering what project to do next considering the cold season is brewing...something inside would be nice, maybe another guitar resto.

[KS]

Pondering what project to do next considering the cold season is brewing...something inside would be nice, maybe another guitar resto.

Or a Honda 250 K4 engine rebuild.

[911hillclimber]

Thought you might remember that suggestion!
TBH too must worry if it went pop, an engine I've never done before etc.
If it seized you would be off and that I can't stand the thought of. Would hurt at any age, let alone 'post 60'

Not sure about the wife's thoughts though she will suspect I will want to do another, but it will (reasonably) be sell this one, then do another.
Nothing to do with £ S D, just space.
It would be a shame to banish this to the damp shed, but it could, just, sit between the Lola and the 911 but I can see that going wrong at some point.

Next project needs to be time consuming to get me through the winter, the 2 guitar projects are far too lightweight, done in a few days, so puzzled what to try next.
Won't be a French motorcycle for sure....

[Hugo 356]

Thought this one was a keeper? From the first post on this thread:

I have always regretted selling my previous Honda restoration a few years back, so decided to do another and keep it

The bike looks ace by the way. Have you ridden it yet or is it still on the stand? We need a photo of you riding the bike before she goes to a new home...

[911hillclimber]

That is still my mindset, but a way to go yet to get it running right.
I can't be sure though if I have achieved that until it gets on the road.
It remains on the table until these carbs are sorted, the working height is just right for working on the thing.
I am sure my wife does not want me to ride it although nothing said yet...
We shall see, seen too much danger to two wheelers man or engine powered locally that un nerves me as much as her!
Time will tell.

[911hillclimber]

Why do these things never go to plan?

Carbs arrived, choke levers modified to resemble the stock carbs, both main jets are the same (and smaller in dia to stock carbs for now.)

Fuel in, switch on...
And the flippin' starter seems all screwed again.

As the electric motor spins, the (new ) rollers engage via the (new) chain and the engine is turned over (throttle closed).
Open the twist grip any amount and the starter stops and there is a nasty racket as the rollers slowly and erratically disengage to a stop,

Does this every time.
If i leave the twist closed the starter will spin and turn the engine endlessly while the button is pressed, touch (rotate) the twist and it all grinds/rattles to a halt.

The twist grip must be interfering with the starter button?

Long hard day working on the house today, will get on it tomorrow. New carbs look great on the engine!