Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: thomaspigeon on September 05, 2020, 08:34:42 PM

Title: CB550 K3 custom project
Post by: thomaspigeon on September 05, 2020, 08:34:42 PM
Hello everyone,

I bought this 550 K3 in parts and putted it back together.

I’ve redone the wiring, got a spark (electronic ignition). But I guess I can have the timing wrong.

I’ve got the carbs ultrasonic cleaned, I change most of the bits inside apart of the needle. Carbs were overflowing with the float at 22mm so I putted them at 24mm (weird?!). Also those carbs are from a 550 f1 weirdly.

The engine was in 1 piece and the previous owner told me it was running.

So I’m guessing the carbs are messing around, how can I be sure some fuel is running into the engine ? Also maybe the spark is not strong enough or wrongly timed...

I’ve got a video that you’ll find below.
https://youtu.be/W0aizX9RmVA

Let me know what your thoughts are.
Thanks
Tom
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 05, 2020, 08:42:48 PM
Hello Tom and welcome to the Forum. You would stand half a chance of it firing up if you fit the air box, air filter etc. These engines need some back pressure to function properly. I'm intreagued at the filter you have on the Breather cover, a rubber tube is what is normally fitted there😁😁😁
Also, the floats need to be set at 22mm.
Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 05, 2020, 08:51:58 PM
As has been said put the air box & filter in place - it reduces the fire risk from a backfire.Even if you have the ignition timing 180 deg wrong the plugs will be wet  after cranking that will tell you fuel is getting through imho.
I assume you know there is some compression?
Likewise did you test for spark at the plugs?

Fuel, spark, compression ignition timing at the right cylinder - it's got to run in some sort of fashion.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 05, 2020, 09:56:04 PM
Thanks for your quick reply everyone! I'll have to try all of this tomorrow.

About the height of the float, how do you mesure it? Carb upside down with the float sitting on? It looks like the floats are getting stuck open very easily.

The previous owner took off the airbox and removed the brackets of the bike, so that will run on pods (I know, not ideal). I'm waiting for some K&Ns but I still have the previous cheap chinese pods, that should do for starting it.

I'll test the compression, and I'll have a look if I have a spark on all the plugs. I know that I have a spark on the cylinder #4. Also as I said, the engine should be a runner.

@nurse Julie , the little pod is to avoid the oil to get straight out I believe...

Tom

Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 05, 2020, 10:13:28 PM
Here is a guide on how to set float heights on your carbs Tom.

http://www.sohc.co.uk/index.php/topic,23233.0.html

The Breather cover on top of the engine that you have the filter attached to, is just a vent, no oil should come out of it (as there is no oil up that high on the engine) it just let's out fumes from the engine.
Title: Re: About to start my project, but it doesn’t...
Post by: deltarider on September 06, 2020, 08:07:11 AM
You say you have spark. How sure are you, it's at the right time? You can check this with a strobe attached or crank the engine manually and listen closely for 'cracks' while watching the timing marks. Has the advancer been apart? Also check spark isn't 'leaked' from plugcaps and/or HT leads to the head.
Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 06, 2020, 09:30:33 AM
You say you have spark. How sure are you, it's at the right time? You can check this with a strobe attached or crank the engine manually and listen closely for 'cracks' while watching the timing marks. Has the advancer been apart? Also check spark isn't 'leaked' from plugcaps and/or HT leads to the head.

Pretty sure most manuals will explain how to set static timing with a simple test lamp arrangement it's not as accurate as using a timing light but certainly good enough to get her running.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 06, 2020, 03:36:41 PM
Quote
Pretty sure most manuals will explain how to set static timing with a simple test lamp arrangement it's not as accurate as using a timing light but certainly good enough to get her running.

I'm using an electronic ignition with an integrated LED, so that should be ok
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 06, 2020, 09:42:45 PM
Hey,

So I spent a couple of hours on the bike today and I figured out a couple of things :
1) not all the spark plugs were firing, some were dead or even the wrong ones! Now I’m about to order some new ones but I’m not sure if I need to take some resisted one or not. I’ve put a photo of my plugs below
2) the electronic ignition was slightly off, apparently the mark F14 need to be aligned with the mark on the crankcase when the LED is switching on. If someone can confirm it needs to be the mark on the left of the F that would be great.
3) I’ve followed your topic to set up the float properly @Julie. Hopefully that will work and not overflow.

Looking forward to get it started!
Thanks for your help everyone

Tom

Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 06, 2020, 09:58:23 PM
With those resisted plug caps fitted, you need to fit non resisted plugs. (D7EA)
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 06, 2020, 10:14:02 PM
@julie thanks!

Out of curiosity, how do you know they have a resistor? The spark plugs were DR7ES so the wrong ones!

I'm wondering if that bike was really running in the past now...
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 06, 2020, 10:28:52 PM
@julie thanks!

Out of curiosity, how do you know they have a resistor? The spark plugs were DR7ES so the wrong ones!

I'm wondering if that bike was really running in the past now...
Those plug caps are standard NGK resisted caps fitted to all Honda CB SOHC/4's. Originally, some models came from the factory with metal, non resisted plug caps so you had to fit resisted spark plugs with that type, or the bike would interfere with all the neighbours TV's. . The metal ones were a pain and a majority were thrown in the bin at PDI and the rubber resisted type were fitted with non resisted plugs.
Title: Re: About to start my project, but it doesn’t...
Post by: deltarider on September 07, 2020, 06:51:12 AM
Hope this pic helps.
How to check plugcaps. Start with checking the resistance in total from one plugcap via the coil to the other plugcap. Realise that new resistor plugcaps are around 5kΩ each. The coils secundary itself is around 14-15kΩ, so with both plugcaps attached, you should read around 24-30kΩ in total. When you read over 30kΩ in total, unscrew both plugcaps to be tested individually. Over time the plugcaps resistance tends to increase. When over 8kΩ, replace. Do not run and resistor caps and resistor plugs. When you have the choice, I'd prefer resistor caps over resistor plugs. Verify plugcaps are firmly connected to the wires. Ofcourse there should be no arcing between plugcaps and/or HT leads and the head. This is best seen in the dark.
Title: Re: About to start my project, but it doesn’t...
Post by: Seabeowner on September 07, 2020, 09:08:02 AM
My CB500 owners manual calls up D-7ES (presume non resistor plug). The metal plug caps had the resistor in them. I have six.
Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 07, 2020, 10:25:08 AM
Maybe bikes are different but it's been my experience that most cars I have worked on will start and run on the wrong plug - obviously not very well usually with flat spots or misfires but they do start.

As regards plug caps I have known them prevent running completely when several have failed on a 4 cylinder engine - likewise carbon leads  are IMHO awful give me old fashioned copper wire .
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 07, 2020, 03:10:02 PM
Hey,

So I tested the plug caps + coil resistance

Plug caps are at 4.5/ 5K ohms so that should be ok

Coil resistance is at 25K ohms for both so all good on that side!

I’m waiting for the new spark plugs to arrive now. Should be on Thursday.

Now I figured another odd thing with the carbs. I tried to sync the sliders with drill bits. But when I open the sliders fully, I always have a gap with carb #2 and #1, the 2 others looks fine. Could you have sliders lifting up at different speed? I should probably create a topic about this.

Thanks
Tom 
Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 07, 2020, 03:32:00 PM
Okay I'm new to this forum but did you check the sliders before you reassembled the carbs on the inlet manifold. It sound to me as though you have sticking sliders near the top of the travel could be muck in the carbs or check the links at the carb top where the springs & little T shaped rods are.

I did the drill bit initial setting on mine and they all fully opened from the throttle action. Is there an issue with the two cable adjustments preventing the throttle from fully opening ? Are you sure you put the T shaped rods in the right way up they seem to act like a pushrod for the throttle movement?
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 07, 2020, 04:10:46 PM
Actually I start to have a massive doubt about my multimeter reading. I’m pretty bad at it

I attached a photo of the reading of the coils HT

What are your thoughts?

@macabethiele I’ll have a look tomorrow at this

Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 07, 2020, 05:39:45 PM
Actually I start to have a massive doubt about my multimeter reading. I’m pretty bad at it

I attached a photo of the reading of the coils HT

What are your thoughts?

@macabethiele I’ll have a look tomorrow at this

Have you checked the battery in your Multimeter I had to change mine after a couple of years use .

Are you getting a good fat visible spark when you check it with a loose spark plug ? Don't forget you get the extra sparks on the other cylinders as there is no distributor fitted.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 12:57:37 PM
@macabethiele I found the culprit, it’s the arm set link that got more play on carb on 1 & 2 not sure if I’ll change it for the price!  https://www.cmsnl.com/honda-cb550f-super-sport-550-four-1976-usa_model467/arm-set-alink_16018323004/#.X1oSxyV4WEc (https://www.cmsnl.com/honda-cb550f-super-sport-550-four-1976-usa_model467/arm-set-alink_16018323004/#.X1oSxyV4WEc)

@julie, I’ve set up the float height following your topic but its overflowing quite a lot on 2 of those. I’m really desperate with those carbs. They are from a cb550 f1 so the height should be 22mm and I made sure both sides of the float were level.

Maybe my overflowing pipe too low for some reasons as I’ve seen they were slightly bent, all the bits inside are new so that can’t be this

The carb reference is 069A Keihin
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 01:15:43 PM
I figured out the pin for the floats are getting stuck...

I’ve attached some photos to make sure I do the things right

Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 10, 2020, 01:21:32 PM
As long as the bottom clip is in the right position this prevents the float from dropping too far down and jamming the valves open- on my Carbs the spring clips span across the width of the bowl stopping the float from dropping too far down Yours should do the same thing if you have them fitted correctly for your carb.  When I had my bottom clips in position with no bowl fitted they stopped the floats from descending too far and allowing the needle valves to drop down too far and jam open.

As regards the carbs fully opening:-
As long as you have the little spring & plunger thing in the right position you should have no trouble with them opening fully. I see no reason why you should ever need to replace the levers as shown in your link unless something is missing. There is what I would describe as a fixed half hip bit that's black in colour and fixed - you then have the small plunger with the wide end facing the fixed cup, then the spring then the lock screw & nut etc. When you fit the throttle link ball into the slot the two halves form a perfect support either side of the ball bit! I cant imagine you ever having enough wear to justify replacement of the link.
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 10, 2020, 01:26:59 PM
I'm just trying to get my head round your photos, something doesn't look right 🤔🤔🤔 I will find a float in a bit and have a look.
Also, if you have fitted all new brass ware, unless they are genuine Honda, there is no guarantee the float vales are shutting fully in the seat.
Title: Re: About to start my project, but it doesn%u2019t...
Post by: thomaspigeon on September 10, 2020, 01:59:07 PM
@macabethiele, the slider open fully but I have a gap that I do not have at the bottom. Im  pretty sure their is more play on 1 arm set as I can feel it but I do not think it is a big deal. If it is, I will change them.

So the float looks upside down for me too but they were that way when I opened them (it does nott mean it is right but they are going the same way on cmsnl)

I managed to have them not leaking with a higher float so the valves are sealing properly

I tried to change the shape of the Float tab were the valve is Seating on to make sure the pin does not get jammed. But it does not work...
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 02:41:21 PM
Thinking the spring in the float valve maybe too stiff and prevent the valve to close properly
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 10, 2020, 03:06:00 PM
So let's clarify. Your bike is a CB550/4 K3 but instead of the standard PD carbs fitted to that model, you have 069a's fitted. Is that correct?.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 03:10:40 PM
Yes indeed. I don’t know why or what happened in the past to have this fitted
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 10, 2020, 03:15:54 PM
Yes indeed. I don’t know why or what happened in the past to have this fitted
Not too unusual really, PD's are the work of the Devil and some owners changed them, and the manifolds, for the 069a's. I can't see why the float needle pin won't depress. Can you pist a pic of the carbs laying down flat, with the floats facing uppermost?.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 05:00:43 PM
I’ll make 1 post per photo so you can have some good quality
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 05:02:29 PM
More
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 05:04:44 PM
I sticked the floats up high to see if I had any leaks and nothing. So it’s definitely float/valve related
Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 10, 2020, 05:28:29 PM
Don't you mean you set them lower or do you mean if you pushed the floats up then it closed the valve ?

The lower the float height in the bowl the greater the leverage between the Tab and the float needle so it shuts off earlier?

When setting my float heights with the Carbs upside down the float Tab would be just  touching the sprung part of the needle valve without depressing it. I then measured the gap between the Carb body and the bottom of the float that on mine were flat - as per NJ's pictures in her float height setting guide.

Looking at your upside down picture the spring clips look the wrong way up to me ? I'm an amature so listen to NJ.
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 10, 2020, 05:39:03 PM
I can see by your photo #1 that the floats aren't level overall and # 2 from the left shows the float arm is bent as the floats are sitting at an angle. As far as the float tang is concerned, remove the floats and flatten the tang so it is flat, its got that hook effect to it at the moment. As Ted has just said, when the floats are fitted, you pull the tang up higher to reduce float height, and push it down further to increase float height. The floats are on the correct way up. The spring clips are the correct way up.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 10, 2020, 08:39:23 PM
Alright after a day of fight. I can say it, no more overflow!

I had to raise some float to 23mm. I don’t know if some spring got more resistance or anything else but it works...

I’ve put everything back on try the spark and.... no spark, I’ve seen a live wire grounding from the electronic ignition... it might be blown inside now.

Reading on the coils after the plug caps is 5000ohms, weird. I have to investigate this now  :-[ :-[ :-[
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 10, 2020, 08:48:24 PM
Alright after a day of fight. I can say it, no more overflow!

I had to raise some float to 23mm. I don’t know if some spring got more resistance or anything else but it works...

I’ve put everything back on try the spark and.... no spark, I’ve seen a live wire grounding from the electronic ignition... it might be blown inside now.

Reading on the coils after the plug caps is 5000ohms, weird. I have to investigate this now  :-[ :-[ :-[

Well done on the carbs. Nothing worse than carbs with an Incontinence problem 😁😁😁😁
Title: Re: About to start my project, but it doesn%u2019t...
Post by: thomaspigeon on September 10, 2020, 10:56:57 PM
Hahaha thanks Julie!

Till the next episode... :D
Title: Re: About to start my project, but it doesn’t...
Post by: robvangulik on September 11, 2020, 12:00:14 AM
I'm just trying to get my head round your photos, something doesn't look right 🤔🤔🤔 I will find a float in a bit and have a look.
Also, if you have fitted all new brass ware, unless they are genuine Honda, there is no guarantee the float vales are shutting fully in the seat.
Maybe that the "hinge " is on the bottom instead of the topside?

Aand there was another page my PC only showed after posting. Sorry.
Title: Re: About to start my project, but it doesn’t...
Post by: paulbaker1954 on September 12, 2020, 02:20:39 PM
Alright after a day of fight. I can say it, no more overflow!

I had to raise some float to 23mm. I don’t know if some spring got more resistance or anything else but it works...

I’ve put everything back on try the spark and.... no spark, I’ve seen a live wire grounding from the electronic ignition... it might be blown inside now.

Reading on the coils after the plug caps is 5000ohms, weird. I have to investigate this now  :-[ :-[ :-[

What brand of electronic ignition is it?
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 14, 2020, 05:04:12 PM
Hey I don’t really know the name of the electronic ignition,

I bought it through David Silver. It’s a Japanese make :  https://www.cmsnl.com/honda-cb750k4-four-1974-usa_model482/ignition-assyelectronic-kokusan_03020300505/#.X1-ToiV4WEc (https://www.cmsnl.com/honda-cb750k4-four-1974-usa_model482/ignition-assyelectronic-kokusan_03020300505/#.X1-ToiV4WEc)

It looks like it’s fried, I plugged a 12V light on the yellow and blue leads and nothing. I probably made a short with that live wire  :-\

Title: Re: About to start my project, but it doesn’t...
Post by: AshimotoK0 on September 14, 2020, 06:13:04 PM
Hey I don’t really know the name of the electronic ignition,

I bought it through David Silver. It’s a Japanese make :  https://www.cmsnl.com/honda-cb750k4-four-1974-usa_model482/ignition-assyelectronic-kokusan_03020300505/#.X1-ToiV4WEc (https://www.cmsnl.com/honda-cb750k4-four-1974-usa_model482/ignition-assyelectronic-kokusan_03020300505/#.X1-ToiV4WEc)

It looks like it’s fried, I plugged a 12V light on the yellow and blue leads and nothing. I probably made a short with that live wire  :-\

I would have serious concerns about having such delicate and unpotted, not even conformally coated,  electronics (on initial viewing from web photo)  in the area normally occupied by the points plate. Even in the mid 1970's Boyer Bransden were savvy enough to have a remotely mounted and full potted electronics module with just inductors on the points 'plate' PCB.

What do other electronics guys on here think? The use of electrolyic capacitors in that location (which gets quite hot ... is also very questionable IMHO)
Title: Re: About to start my project, but it doesn’t...
Post by: SteveD CB500K0 on September 14, 2020, 07:00:05 PM
Conformal coating.

Takes me back…


Sent from my iPhone using Tapatalk
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 21, 2020, 10:07:38 PM
Hello everyone,

So I need to change the name of this topic as my project started!  ;D

For some reasons the electronic ignition came back to life...

Now, it's running really poorly that was kind of expected. When I open the choke fully it dies, I guess it's too lean so I'll have to change the idling and main jets. I didn't make the baffle yet and I still didn't receive my new pods so I'll have to wait for this being done. I found it kind of unresponsive/delayed when twisting the throttle.

Also, it's kind of ticking on the top engine so I'll have to check those valves.

When I checked the spark, it wasn't huge either...

You can watch/ hear it below :
https://www.youtube.com/watch?v=af05AX-ZU94&ab_channel=TheTallTom (https://www.youtube.com/watch?v=af05AX-ZU94&ab_channel=TheTallTom)

https://www.youtube.com/watch?v=tm86UACgQyk&ab_channel=TheTallTom (https://www.youtube.com/watch?v=tm86UACgQyk&ab_channel=TheTallTom)

Let me know what you guys think
Thanks

Tom
Title: Re: About to start my project, but it doesn’t...
Post by: Nurse Julie on September 21, 2020, 10:30:50 PM
That top end ticking sounds like a leaky exhaust manifold gasket.
Title: Re: About to start my project, but it doesn’t...
Post by: thomaspigeon on September 21, 2020, 10:52:24 PM
That’s a good news, I’ve got a set of new ones!!
Title: Re: About to start my project, but it doesn’t...
Post by: SteveD CB500K0 on September 22, 2020, 06:53:08 AM
You can change the name of your thread.

Go to the first post and edit it there.
It won’t change on the existing replies but will on all future ones.

Steve


Sent from my iPhone using Tapatalk
Title: Re: About to start my project, but it doesn’t...
Post by: McCabe-Thiele (Ted) on September 22, 2020, 10:56:14 AM
Wow that sound of it running is music to my ears I'm really chuffed for you- that is where I want to be by mid October at the latest if I can!

I expect mine to be noisier due to the known cam chain rattle and leaking exhaust though. ;D
Title: Re: CB550 K3 custom project
Post by: thomaspigeon on February 02, 2021, 12:11:24 AM
Hey everyone,

So after a couple of month going quiet and working on the bike, I'm back!

So far I've rebuilt the top end, new pistons, re-bore, new rockers, new valve springs, gaskets, you name it.
Also I have re-done the wiring from the ground, I'm also gonna make my lithium battery next week. Not saying I've put some elbow grease to polish the exhaust, engine...

Thanks to the lockdown I literally went down the rabbit hole to make this bike nice and shiny

Now, I have a question. My oil pressure warning light doesn't go off when the engine is not running. I tried to test the continuity between the top screw on the oil pressure switch and the engine or the frame but nothing. That's should mean the sensor doesn't ground anymore if I'm right. Is it the kind of thing that happens often? The oil light worked for some time (like a couple of minutes) beforehand. I tested the continuity between the Neutral switch and the frame and it works fine.

I test the oil pressure and it's fine (65/70psi)

Let me know what you think!
Thanks

SimplePortal 2.3.5 © 2008-2012, SimplePortal