Author Topic: Late CB750 K0 Mold to Gold, the nugget. (Read 37416 times)

Terry in Australia · « **Reply #300 on:** June 14, 2021, 08:48:04 PM »

Quote from: Don R on June 14, 2021, 09:07:24 AM

Shellac style sealer pic.

https://photos.app.goo.gl/pysLLyq2eVWvzZiX7

Yep, that looks like the old Permatex gasket goo mate, I still have a bottle that I reckon I bought 20 years ago, and still use now and then. From memory there was a "hardening" and "Non Hardening" type, and I reckon I had a bottle of each, but can't find the other one, so maybe it "Hardened" in the bottle and I threw it out?

Don R · « **Reply #301 on:** June 14, 2021, 09:16:20 PM »

A little scraping with an old screwdriver and the sealer came off the outside, I have a brass brush to finish it up with.

Don R · « **Reply #302 on:** June 17, 2021, 02:02:19 PM »

I tried to put on the fuel line but failed miserably with Grandkids wanting attention. They win every time. They've gone home now, I'll try once more to get the hose over the carb nipples.
The question is now, put the 341 exhaust on it or wait for no number pipes and start on my brothers k4 one owner? There's an F basketcase with a supposed big bore motor in my brothers shop, that would get the drag bike running quickly. It used to be mine, I just need to go get it.

Don R · « **Reply #303 on:** June 23, 2021, 07:16:09 PM »

I rode it today, one carb pissing gas, That cured it's self. New fuel lines are on, inline filters are off. I will not judge but maybe grit from the "genuine" Honda 5.5mm hose that says cmn on it. Maybe not. I ran the dog piss out of it to try and dry the airbox it still has that GM quadrajet with the flipped air cleaner lid sucking sound at WOT.
#3 has a hanging slide, it might be the cable or it might be the slide it's self. When I reached under the tank and pushed down on the cable the idle returned to normal. It has the individual carb tops so I can pull the tank and service the one carb on the bike. My parts tub has two or three 4-1 cables in case I need one.
It also needs a clutch cable, it pulls hard, or maybe I should look in there it might have big springs.
It also sits high, partly the dohc shocks and partly the firm DSS repro seat. I like the $160 sandcast repro shocks available. 4-1 has them, I might buy another set.
I'm liking the Jardine 4-2 mufflers on stock pipes. It's a shame the chrome is crappy on the left side.

I also gave the oil tank a flush and an auto trans drain plug since it has a self tapper in it. I topped it off with a dose of rislone engine cleaner and will change the oil the next time it's warm.

Terry in Australia · « **Reply #304 on:** June 25, 2021, 02:57:11 AM »

Ha ha, when you get to the stage where you're questioning the authenticity of the fuel line Don, you know that you've become an anal rivet counter! I like my (non original) clear fuel line, so I can look at it and know if there's fuel getting to the carbs, and if it's going into your carbs too. No issues with "floaties" either, but I run inline filters too, because there's probably some crap inside my tank, and I don't know how good the OEM filter on my petcock is.

I recently discovered that all the whining I was doing about the heavy throttle spring on my K2 bitsa's carbs was actually the 50 year old cables I was using, I didn't realise that just because the cables were free they hadn't dug furrows into the inside of the sheaths, so it was a huge surprise when I installed new cables that looked better with my lower bars, that suddenly the horrible heavy spring was not much different to the K0's new 1 into 4 cable's "super-light" pull.

Same/same for my clutch cable, I knew something was up with it because it "groaned" when I pulled the clutch in, but once again, I couldn't get over just how light the clutch feels now. This weekend (miserable weather permitting) I'll throw away the old speedo and tach cables, as I suspect that the bouncy needles might in part at least, be caused by the #$%*ty old OEM cables that I just couldn't bear throwing away. I think I'll give my K0 a birthday and replace any old cables on it before our next ride too.

PeWe · « **Reply #305 on:** June 25, 2021, 04:18:34 AM »

Weaker throttle spring will make life easier for the throttle hand and rubber grip.
Honda stock is heavy.

OK with harder springs for valves and clutch, not for throttle!

Don R · « **Reply #306 on:** June 25, 2021, 10:05:37 AM »

My red and green bikes have a much easier clutch pull, My next project (hot rod bike) will have 400F bars and it has a +6" cable now so I'll order a short cable and a stock cable.
The 4 cable carbs are a little less adjustable than the later 2 cable type I currently have too much slack at the grip and I suspect these need balancing more often just due to the 4 cable design.

Terry in Australia · « **Reply #307 on:** June 25, 2021, 06:55:14 PM »

Quote from: PeWe on June 25, 2021, 04:18:34 AM

Weaker throttle spring will make life easier for the throttle hand and rubber grip.
Honda stock is heavy.

OK with harder springs for valves and clutch, not for throttle!

Yeah mate, I forgot to mention I'd changed out the spring to one recommended by someone here too a couple of years ago, but I don't think it made much difference, the worn out old cables were the biggest problem in my situation.

PeWe · « **Reply #308 on:** June 25, 2021, 11:32:06 PM »

Quote from: Terry in Australia on June 25, 2021, 06:55:14 PM

Quote from: PeWe on June 25, 2021, 04:18:34 AM
Weaker throttle spring will make life easier for the throttle hand and rubber grip.
Honda stock is heavy.

OK with harder springs for valves and clutch, not for throttle!

Yeah mate, I forgot to mention I'd changed out the spring to one recommended by someone here too a couple of years ago, but I don't think it made much difference, the worn out old cables were the biggest problem in my situation.

The strange thing is that I changed spring when I cleaned carbs to use them on my K2. The stock spring had been there when using them on my K6 for 90.000 km.
Long rides from early morning to late evening and more on Autobahn and south.

The spring was obvious when handling the rack off bike after handling my old Mikuni VM29 and even easier operating TMR flat slide setup.
Hard operating cables not fun when throttle wire can suddenly snap.
Mine had worked rather long now. I remember when wire snapped so I had to tighten the idle screw so I could ride home. Cables hopefully better routed now with less wear.

Terry in Australia · « **Reply #309 on:** June 27, 2021, 12:51:46 AM »

Yep, routing the cables are the key for a light throttle pull, more so on a K0 with the 1 into 4 cables, all sorts of horrible things can happen if a K0's cables aren't routed correctly.

Don R · « **Reply #310 on:** June 27, 2021, 08:41:38 AM »

The first ride on my K0 I was in a parking lot doing a u turn next to my wife's car and the poorly routed single cable caught on something in a tight parking lot turn. The revs went to the moon. I already was on the clutch so other than a lesson well learned and a rapid pulse no harm was done.

PeWe · « **Reply #311 on:** June 27, 2021, 11:14:39 AM »

About routing throttle cables. It was many years ago I gave up the stock routing with one cable on each side of frame in tight over coils. Not via top joke either. (Higher US bars can most likely have that routing)
I have both beside each other on left side of frame with stock carbs using stock headlamp ear.

My blue K6 has very light working throttle. Not stock headlamp ear make routing easier.

Don R · « **Reply #312 on:** June 28, 2021, 09:45:44 AM »

Thanks for the photo's. They are worth a thousand words.
I rode it again yesterday, it's low on fuel and on reserve it runs rough, all four pipes are hot, I need to read the plugs to see what's going on. It must be in the carburetors dangit.
My new oil tank drain fitting was leaking into the sidecover, I had pinched the rubber o ring, being used to compressing a copper washer, it was overtightened. I held a finger over the drain hole while changing the o ring with one hand.
Riding this bike back to back with the Hot Rod 836 there is an astonishing difference. I need to get a new helmet and run the 836 at the drag strip.

Don R · « **Reply #313 on:** July 26, 2021, 04:01:40 PM »

It got new plugs and still runs awful. Time to drop the carb bowls and have a look inside. The tank was coated with Caswell by a pro, it appears solid inside but the bowls may tell a story. The petcock has a tiny drip too so I've got work to do. It has new plug caps and 1/4" cut off the wires, the dwell and timing are spot on so it's got to be in the carbs.
The fast idle when warm seems to have abated or at least isn't noticeable as bad as it runs.

Terry in Australia · « **Reply #314 on:** July 26, 2021, 05:30:25 PM »

Yep, one thing I've noticed with the two running K0's I've owned is if it's not running good, it'll usually be the carbs or the throttle cables.

Don R · « **Reply #315 on:** July 26, 2021, 10:16:33 PM »

Thanks, the cables are suspect too, I normally get new ones, didn't this time. I even wondered if I got a slide backwards. You start to doubt things when you run low on ideas. It has 4 hot pipes at least. I want to get it dialed in before adding the 4-4 exhaust and turning it blue. L0L.

Terry in Australia · « **Reply #316 on:** July 27, 2021, 01:40:59 AM »

A stupid question Don, but hey, it's only me, have you done the valve clearances? I can only remember a burned out valve in one CB750 out of the 20+ that I've owned (probably closer to 40...) but it's a possibility?

Don R · « **Reply #317 on:** July 27, 2021, 03:57:26 AM »

I'm sure I did when I first got it but since then I've seen a broken rocker arm on another bike, so it's worth a look.

Don R · « **Reply #318 on:** September 21, 2021, 08:19:26 PM »

Now that I stored a car and made some space I can get this nugget on the lift to check it out better. I'm pretty sure I'm putting on the 341 repro pipes to get it finished and see if I can transfer the registration from Vermont to Illinois. I'm increasing my shop time, this weekend is the last Drag race and the racecar can get drained and stay intact. (Hopefully)

Edit, the racecar completed the 6 race season unbroken. Good news for other projects.

Don R · « **Reply #319 on:** October 29, 2021, 11:52:15 AM »

I may buy other 750's and the nugget will be for sale, the second annual Vermont registration is due in the mail today. (It didn't come)
I'll need to try the VT/Illinois registration swap.

I took off the rear wheel, rebuilt the brake drum and got out the new Continental rear tire.

HondaMan · « **Reply #320 on:** October 30, 2021, 09:17:01 AM »

Quote from: Don R on October 29, 2021, 11:52:15 AM

I may buy other 750's and the nugget will be for sale, the second annual Vermont registration is due in the mail today. (It didn't come)
I'll need to try the VT/Illinois registration swap.

I took off the rear wheel, rebuilt the brake drum and got out the new Continental rear tire.

I've enjoyed this thread!
You've inspired me to start now 3 project bikes that I'll spend most of the next 6-10 months rebuilding:
a 750K(?) (in my shed for 6+ years),
a 550K1 (fortunately all it needs is a good cleaning and an engine rebuild for oils leaks and longer life),
and my long-lonely 350F2 that looks at me like my Shih-Tzu does every morning, each time I go to the shed for other parts.

Have to figure out some names for them...

Don R · « **Reply #321 on:** October 30, 2021, 10:37:03 AM »

I had fun with the names. It also made me smile to think that I inspired you Mark.
I did my car show with the three colors of K0 and made a new friend who is supposed to call me tonight about selling his old drag bikes.

Don R · « **Reply #322 on:** October 30, 2021, 10:38:34 AM »

My junk,

Terry in Australia · « **Reply #323 on:** October 31, 2021, 02:21:51 AM »

As much as I love your K0's Don, if I had a choice of riding your K0's or driving your dragster, I'd much rather drive your dragster. Just once.

Don R · « **Reply #324 on:** October 31, 2021, 09:32:19 AM »

I got the matching back tire on, swapped the worn brake shoes and repacked the wheel bearings. They spun smoothly after a little cleaning so I got out the packing tools and filled them up.
I neglected to do this so I could get them all to the cruise.
I have a junk shop vac base that works great to lay the rim over to wrestle tires,

News:

Author Topic: Late CB750 K0 Mold to Gold, the nugget. (Read 37416 times)