Author Topic: CB 500 Four (1972?) Full Restoration (Read 140314 times)

calj737 · « **Reply #925 on:** December 05, 2015, 02:53:02 AM »

Before you pull the carbs, rap on the body of the carb with a screwdriver handle. Its very common for newly rebuilt carbs to stick a bit, and/or some debris to hang up the float needle. The overflowing may settle out after a few minutes too, especially if you run the motor (hint, hint!)

DH · « **Reply #926 on:** December 05, 2015, 07:14:00 AM »

Yeah, that first...sorry, I was half asleep when I posted.

onetruepunk87 · « **Reply #927 on:** January 09, 2016, 12:29:06 PM »

Hey Mick, any updates?

MickB · « **Reply #928 on:** January 13, 2016, 01:46:47 PM »

OTP thanks for the prompt, I've been away for a month and its been stinking hot, today 106° in the shade and I've not been too enthused.
But now you've prompted me I'll get cracking again.

Trad · « **Reply #929 on:** January 13, 2016, 01:52:41 PM »

This is coming together beautifully. So nice!

rtbmrgl · « **Reply #930 on:** February 13, 2016, 08:44:53 PM »

Quote from: MickB on November 20, 2015, 10:28:48 PM

Nice paint, what did you use for the chrome trim. I used door edge trim from Autozone on my CB500, not as wide as original.

DH · « **Reply #931 on:** February 14, 2016, 07:35:47 AM »

This is close to stock width, even tho its listed as seat trim, it works good on the tank. close to whats in pic.

http://www.ebay.com/itm/HONDA-CB-750-CB750-CB750F-CB750K-SEAT-COVER-TRIM-72-76-/120934462094?hash=item1c2841728e:m:mTEIHjKJD3G26h3lr1dAipA&vxp=mtr

MickB · « **Reply #932 on:** March 02, 2016, 12:35:17 AM »

Hey guys I'm not dead (even though most of us nearly are or should have been with the life we used to lead), been sooo busy for last 3 months sold and moved house, holidays, unpack new house, etc etc etc.

All I've done is kick the motor over to ensure oil in top end and rings don't seize.

Should be back to it in the next few days, I've only got to make it run (easily said and hopefully tap the #2 carbie bowl to stop a leak) and it's finished.

Tank and covers are wrapped in a blanket and save in a box in my office. Ivan the ace mechanic loaned a bottle with a tube on to get juice into it until it's ready.

BTW I'm thinking very hard about the new Indian Scout, can't stand the BROWN frame on the Scout 60, what were they thinking? I even wrote to Polaris in the USA and mentioned no self respecting bikie would ride a BROWN bike and I know Honda had a brown 500 and I'll bet they didn't sell many.

bryanj · « **Reply #933 on:** March 02, 2016, 10:40:58 PM »

The Brown Honda was the seat on a 500 Twin and in the UK we reconned it was brown so that the incontinence didn't show

MickB · « **Reply #934 on:** March 03, 2016, 01:47:16 PM »

rtbmrgl I got the chrome trim off eBay, it said it was extra wide. It's close to the full depth but not quite, there's about an ⅛ th of an inch still showing on the join.

MickB · « **Reply #935 on:** March 03, 2016, 04:26:30 PM »

Quick question.

We have unleaded petrol here in Oz, should I put a lead additive in the juice?

bryanj · « **Reply #936 on:** March 03, 2016, 11:41:39 PM »

Nope, all Honda's were designed for unleaded

MickB · « **Reply #937 on:** March 03, 2016, 11:52:23 PM »

BJ back in the day I only used super in my 750/4 and it had lead in the juice to stop pinging.

bryanj · « **Reply #938 on:** March 13, 2016, 09:36:55 AM »

I used leaded as well but the Hondas were designed for the US where everything went unleaded a long time before UK or OZ, using leaded causes no problems when designed for unleaded but the other way is a disaster waiting to happen

MickB · « **Reply #939 on:** March 25, 2016, 08:17:06 PM »

Well I'm finally able to get back into the bike.

The last time I put petrol into the carbies the #3 leaked.

I pulled them off (just as well) and have found this.

Anyone got an idea why it's got this green stuff inside the bowls and around the main jet, it's crusty and gritty.

I've also found 2 floats not set at the correct height - 22mm I believe?

Also one of the bowl gaskets was pinched, maybe why it was leaking.

Battery is in charge.

MickB · « **Reply #940 on:** March 25, 2016, 10:03:14 PM »

I think I've found out why the carb was leaking, I had this in upside down

MickB · « **Reply #941 on:** March 26, 2016, 01:38:42 AM »

Just wondering if that green is from cheap Chinese jets?

calj737 · « **Reply #942 on:** March 26, 2016, 04:09:05 AM »

Quote from: MickB on March 26, 2016, 01:38:42 AM

Just wondering if that green is from cheap Chinese jets?

It had better not be. Because if it is, then you didn't use Keihin brand jets and that means you're due a major flogging behind the woodshed. You know, the kind Jesus got.

MickB · « **Reply #943 on:** March 26, 2016, 04:21:03 AM »

It's good to be back and to get the rounds of the kitchen from you again Cal. Guilty as charged, In my defence I bought them very early in the project and yes I bought the cheapest I could, I've learned my lesson and am suitably chastened.

However, I think I need to really check out the carbs I've got, the numbers etc. the existing jets were 98/ 38s, replaced with 100/ 40s.

Has anyone heard anything about Sigma Jet Kit made in the USA? They seem to really know what they're about.

Any ideas about the green colour?

calj737 · « **Reply #944 on:** March 26, 2016, 04:27:58 AM »

I don't know Sigma, "jetsrus" and "sirius" are 2 companies that get quite often referred. Its been a while, but exactly what happened to your stock brass? Even the float needles have been replaced?

https://www.jetsrus.com/a_jet_kit_street/honda_500_CB500K_1971-1973.htm
Float needle valve assembly 18-4762 $13.99

MickB · « **Reply #945 on:** March 26, 2016, 04:29:13 AM »

Here's the eBay advert.

https://www.ebay.com.au/ulk/itm/331698806524

I recon I've got 550 carbs and just did them up thinking they're 500, a newbie error.

Note the 550 carbs are 98/ 38 jets

calj737 · « **Reply #946 on:** March 26, 2016, 04:31:14 AM »

I'd steer very clear of that kit...

MickB · « **Reply #947 on:** March 26, 2016, 04:33:30 AM »

Porquois? It sounds pretty good

calj737 · « **Reply #948 on:** March 26, 2016, 04:42:42 AM »

From their advertisement; These are NOT Keihin brand jets. A jet is not a jet... Needles. An aftermarket needle is VERY different from stock needles. They may be "made to be compatible" but their specific tapers do differ sufficiently that tuning basis is far from relevant to each other.

That "jet kit" is designed for newer bikes whose carbs are far more restrictive due to EPA regulations and some "wanna go faster" DIY is going to alter his stock carbs by drilling jets (an awfully bad idea) and modifying the bodies. You've spent thousands of hours to put your bike together right. The stock brass (or replacement stock brass) is absolutely the best option for your bike. This is a documented fact on more threads than can be counted.

If stock brass weren't available, then it would be down to finding the least worst option.

As for why your fuel converted so quickly, that's likely down to moisture in the fuel. If you must stop your bike for lengthy periods, be certain to fill the tank, and I like to run the carbs out of fuel. (switch off the petcock, let the carbs starve out). Or, you could add a fuel storage additive and run it/fuel through the engine for several minutes to insure it completes the circuit.

I don't see the brass in your pictures tarnished up and turning green, so I don't think the Chinese brass is the cause. I think its just poor fuel.

MickB · « **Reply #949 on:** March 26, 2016, 04:45:35 AM »

Thanks for the explanation. The jets I've used are 100/40s just not sure how they'll go with the 4 into 1s.

But I know I'm going to get it going over the next week or so - I'm back!

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Author Topic: CB 500 Four (1972?) Full Restoration (Read 140314 times)

DH

DH