Topic: K3 Project has now started.

[MauiK3]

Believe it or not that's candy blue-green. It sure does not photograph well.

[algophobe]

Correction
The POR 15 engine paint color is called cast aluminum from their Detail Paint line.

is it a rattle can or component? you said think coat but it looks really good. I used rattle can VHT, having misgivings about durability though.

[MauiK3]

The color stuff (candy blue green) is all Yamiya. The base coat black on the frame is brush on after many cleaning steps, the chassis black top coat is rattle can. The cast aluminum on the engine is rattle can. Here in Hawaii they call it sho-sho can.
I cleaned with simple green, then zylene and then acetone, lots of ventilation and a mask.

[MauiK3]

More progress today. Got the engine all snugged up in the frame, mounted the oil tank and lines. Put the battery back in. Once again, the start circuit does not work, have to tackle that later.
Filled the tank with oil and cranked using the starter wire to the battery +.
Got oil pressure in short order, could see it in the valve train, whew.
On to sorting out the solenoid problem. I thought I was done with wiring mysteries.
All in all, not a bad day.

[budman]

Looks great.

[HondaMan]

Believe it or not that's candy blue-green. It sure does not photograph well.

That's the color I want for mine, but you're right: even in the OEM versions, it always looked more like a Baby Blue in pictures. It must be something about [then] film or [now] color sensors. In the old Cycle World and Cycle magazines, when they pictured the K0 750 in the Blue-Green, it looked like a light blue, very un-exciting. I thought it was another color I hadn't yet seen in real life until one of the authors mentioned that his test ride was the Blue-Green color (K1 then), but it also looked like a light blue in his pictures.

[MauiK3]

Starter solenoid problem, wow

I seem to have an odd K3. Even though I have a starter logic box, there is no clutch switch. I can't figure out what the logic box would do. I have looked at many wiring diagrams and my bike does not match any.
Anyway, I can't seem to get the solenoid to work with the harness, there is no power anywhere in the black wires associated with the circuit. I have verified the solenoid works with jumpers. I have verified the button works. What I HAVE done to make it work is make the start circuit work like a K0.
To do this I have applied switched power from the ignition switch to one of the connectors on the solenoid, which in this case is pink (!) This is the connector that would connect to the black coming out of the harness. The other connector is yellow/red, it goes through the start button and grounds when pushed, the starter runs. This setup works.

Incidentally, when I check all the blacks for continuity they beep me. When I turn on power, no power shows up in the blacks at the logic box or the connector at the solenoid.
Looks like I have to make a jumper and revert to K0 start wiring.

[MauiK3]

My candy blue green parts were purchased as a set from Yamiya. I think they got it pretty close. A friend of mine here is an excellent painter and he said he'd paint it but I was worried about getting the color right using the kit from the vintage paint guys.
I hope it holds up well although it will never be stored outside. It will be "take the cover off, drive out of garage, go for a spin, back under cover in the garage". It also won't spend much time parked anywhere out of my line of sight. Big contrast from my younger days. As a lad at Florida State I had to park it out in the lot near my dorm with a huge chain on it. They still stole it. I bought another and believe it or not Florida Highway Patrol found it later in running condition. I sold it to a friend. I had a good time commuting to where I lived at the time (Jacksonville). Interstate 10 was not done then, lots of curvy roads.

[MauiK3]

Got some more of the front put together. Have to go get some fresh brake fluid and fill the system up. I hope my vacuum bleeder owes the trick. The headlight works and I like the euro running light even though that's not what they use them for. It will be on all the time. I put the turn signal buzzer inside the headlight, much more endurable now.
On to the rest!

[HondaMan]

Starter solenoid problem, wow

I seem to have an odd K3. Even though I have a starter logic box, there is no clutch switch. I can't figure out what the logic box would do. I have looked at many wiring diagrams and my bike does not match any.
Anyway, I can't seem to get the solenoid to work with the harness, there is no power anywhere in the black wires associated with the circuit. I have verified the solenoid works with jumpers. I have verified the button works. What I HAVE done to make it work is make the start circuit work like a K0.
To do this I have applied switched power from the ignition switch to one of the connectors on the solenoid, which in this case is pink (!) This is the connector that would connect to the black coming out of the harness. The other connector is yellow/red, it goes through the start button and grounds when pushed, the starter runs. This setup works.

Incidentally, when I check all the blacks for continuity they beep me. When I turn on power, no power shows up in the blacks at the logic box or the connector at the solenoid.
Looks like I have to make a jumper and revert to K0 start wiring.

As they say, "...trust me...", you don't want the safety module anyway.
The K0-K2 start circuit has proven to be far more reliable over the years!

[HondaMan]

I put the turn signal buzzer inside the headlight, much more endurable now.
On to the rest!

Now, THERE's a good idea!
Does your K3 not include the "beeper kill" switch? The earliest ones did, but the later ones did not. It was hung below the turn signal switch, as a pushbutton to stop it, while you held the button in. Mine is like this.

[budman]

A friend of mine here is an excellent painter...

His name wouldn't happen to be Ron, would it?

[MauiK3]

No beeper kill switch. It seems to be a strange mix of K2, K3. I got the bike from the original owner who did not make any changes other than the exhaust when it rusted out. I have a beeper (now in the headlight which tones it down nicely), no beeper silence button, no clutch switch. Where would the clutch switch be, up on the lever somewhere? That would require another set of wires on the left side I assume since they didn't have bluetooth back then. I am absolutely going to eliminate the logic box that does not seem to do anything at all without a clutch switch.
I can't tell you how gratifying it was to see oil flowing out around the rockers when I was cranking it.
So today I am going to fill the brake system and see if I can get it air free with my vac bleeder. Might be tricky with two calipers. Otherwise I will do the partially depressed lever and let it soak method. Dual discs really make it look crowded down around the front wheel, I hope they work well otherwise I'll just remove one.

[HondaMan]

No beeper kill switch. It seems to be a strange mix of K2, K3. I got the bike from the original owner who did not make any changes other than the exhaust when it rusted out. I have a beeper (now in the headlight which tones it down nicely), no beeper silence button, no clutch switch. Where would the clutch switch be, up on the lever somewhere? That would require another set of wires on the left side I assume since they didn't have bluetooth back then. I am absolutely going to eliminate the logic box that does not seem to do anything at all without a clutch switch.
I can't tell you how gratifying it was to see oil flowing out around the rockers when I was cranking it.
So today I am going to fill the brake system and see if I can get it air free with my vac bleeder. Might be tricky with two calipers. Otherwise I will do the partially depressed lever and let it soak method. Dual discs really make it look crowded down around the front wheel, I hope they work well otherwise I'll just remove one.

I liked my dual discs in the rain: it was like 1-finger power brakes! Eventually I turned the forks around to have the calipers on the back, which lightened up the steering sensation in parking lots and such places, but it made them more "wet" in the rain again. Honda was pretty smart, putting the caliper AFTER the rain flies onto the engine...

The K2-3 mix is not uncommon: I am presently working on a K3-1 mix in an engine. The top end is (virgin) K1, the bottom end's serial number is mid-K3. I'll find out tomorrow what clutch is inside! It all fits...

The clutch's 'safety switch' was pressed into a little hole near the pivot end of the mount bracket, from the lever's side. Yours might have a little hole in the bracket at the site, if it had one. For a VERY short time there was a 4-post start solenoid in late 1972/K3 that had the headlight disconnect function, breaking into the headlight fuse's circuit to kill all the lights during Start. This was replaced with the switch we all know now, which only douses the headlight during Start.

[MauiK3]

I will post photos but I am having trouble with brake fluid fittings. I have all new lines, banjo gaskets, calipers, bleeders. Both bleeders weep slowly even when TIGHTLY closed. One set of banjos at the splitter weeps too. I have tightened them more than I like. I ordered new bleeders and banjo gaskets.
I had no trouble bleeding with a vac bleeder.
Using DOT4.
Weird problem.

[PGF550F]

I will post photos but I am having trouble with brake fluid fittings. I have all new lines, banjo gaskets, calipers, bleeders. Both bleeders weep slowly even when TIGHTLY closed. One set of banjos at the splitter weeps too. I have tightened them more than I like. I ordered new bleeders and banjo gaskets.
I had no trouble bleeding with a vac bleeder.
Using DOT4.
Weird problem.

Try loosening and re-tightening the fittings where you have the weeping. I had to do that a couple times when I replaced the brake hoses on my 550. Helps to seat the sealing surfaces into one another. Had a bad leak at the splitter and a couple loosen/ re-tighten sequences seated everything together for a leak free seal. 3 years later still no leaks.

[seanbarney41]

I will post photos but I am having trouble with brake fluid fittings. I have all new lines, banjo gaskets, calipers, bleeders. Both bleeders weep slowly even when TIGHTLY closed. One set of banjos at the splitter weeps too. I have tightened them more than I like. I ordered new bleeders and banjo gaskets.
I had no trouble bleeding with a vac bleeder.
Using DOT4.
Weird problem.

Try loosening and re-tightening the fittings where you have the weeping. I had to do that a couple times when I replaced the brake hoses on my 550. Helps to seat the sealing surfaces into one another. Had a bad leak at the splitter and a couple loosen/ re-tighten sequences seated everything together for a leak free seal. 3 years later still no leaks.

+1 especially for the bleeders...The only time I have had a banjo leak was with brand new washers.  Hundreds of leak free assemblies with used washers.

[MauiK3]

Is there a trick to loading a short video? I'd like to load 1 minute of it running.

[HondaMan]

Today's "sealing" washers for these brakes seem to be harder (less annealed) than the OEM ones. Like mentioned above, I've had to set-unset-reset them several times to make them stop leaking.

[MauiK3]

I took it for a brief ride today.
I started this back in January and have spent quite a lot of time bent over the various parts since. I have touched all 2000 parts at some point. My patient and supportive wife Jackie urging all the way. It was a running K3 in good relative shape, mostly unmolested. It did, however, have the effects of 43 years in San Diego and Maui. There was plenty of corrosion starting to accelerate. Rubber products were toast, seals starting to leak, head bearings etc worn. It did not want to idle correctly and the handling was vague.
I took it all apart and made it look (mostly) like my K0 I had back in the day. It was running very rich.
Without making a long list it's full of a lot of new parts and fasteners. I put it together to hopefully wear well here in our marine environment on Maui, many stainless fasteners.
Head and cylinders by Hondaman
Gauges by Marcel
Disks by True Disk.
Oil hoses by Rafi
Brake hoses by Sean at Stainless Steel
And a whole boatload of parts from Yamiya and David Silver.
Tires from Revzilla
Spokes (stainless) from Buchanan

So far, it runs great, have not taken it far yet, need to satisfy myself that it's ok.
Handling seems much surer with the Hagons, new fork tubes, new tires (rib front, block rear.), swing arm bushings and tapered bearings in the head.
Oh, no smoking on start up.
One funny thing, it smells just like I remember my new Hondas smelled many yeas ago.
There are a few things I may do yet. I think I want the larger master cylinder, I'd like a little less lever travel. I need the fuel tank lower trims, mine were warped. The rear brake arm chrome is tired and I didn't get one. I'd like a different rack for the back. There is a great welder/fabricator here, I may see if he'd put together a stainless one that fits better, the rack on it came with the bike. Have to have the back rest for my wife.
Anyway, here are a few photos.

[MauiK3]

I have not done this kind of work in a long tim, it was fun getting the precision tools out again

[MauiK3]

No leaks so far

[MauiK3]

Hondaman's book is a MUST for this, I would have been lost.

[MauiK3]

It sure does not photograph as candy blue green but it most certainly is.
I still need to check the mixture. Right now there is a slight popping on back down which might be ok?
108 jets, needles in the middle, no number Yamiya exhaust, stock air filter and box with no box mods. Hondaman head, .5 mm over pistons.
It sounds wonderful.

[HondaMan]

It sure does not photograph as candy blue green but it most certainly is.
I still need to check the mixture. Right now there is a slight popping on back down which might be ok?
108 jets, needles in the middle, no number Yamiya exhaust, stock air filter and box with no box mods. Hondaman head, .5 mm over pistons.
It sounds wonderful.

Some things to try: today's gas runs 'richer' than the same octane years ago used to, so maybe turn int the idle air screws a tad to see if it helps with the decel popping. That is caused by a momentary overly-rich mixture accumulating in the pipes near the head during decel. Another 'cure' is to either lower the float bowl levels 1mm or so, or try the 105 mainjets with the needles where they now sit.

The front brake: slip a 0.004" feeler gage between the inside puck and the disc, and adjust the screw/locknut for a light drag on the feeler (both side, if dual discs). This will reduce the loose-lever feeling. But - when I had dual front discs, I could lock the front wheel on wet roads with 2 fingers, long before the lever got near the handgrip!