Author Topic: CB550 K3 custom project  (Read 1551 times)

Offline thomaspigeon

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CB550 K3 custom project
« 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
« Last Edit: February 01, 2021, 11:53:25 PM by thomaspigeon »

Offline Nurse Julie

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Re: About to start my project, but it doesn’t...
« Reply #1 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.
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Offline Macabethiele (Ted)

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Re: About to start my project, but it doesn’t...
« Reply #2 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.
« Last Edit: September 05, 2020, 08:54:07 PM by Macabethiele »
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Offline thomaspigeon

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Re: About to start my project, but it doesn’t...
« Reply #3 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


Offline Nurse Julie

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Re: About to start my project, but it doesn’t...
« Reply #4 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.
Im a Nurse, trust me, this won't hurt.....much !!!

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Offline deltarider

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Re: About to start my project, but it doesn’t...
« Reply #5 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.

Offline Macabethiele (Ted)

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Re: About to start my project, but it doesn’t...
« Reply #6 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.
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Offline thomaspigeon

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Re: About to start my project, but it doesn’t...
« Reply #7 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

Offline thomaspigeon

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Re: About to start my project, but it doesn’t...
« Reply #8 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


Offline Nurse Julie

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Re: About to start my project, but it doesn’t...
« Reply #9 on: September 06, 2020, 09:58:23 PM »
With those resisted plug caps fitted, you need to fit non resisted plugs. (D7EA)
« Last Edit: September 06, 2020, 10:01:01 PM by Nurse Julie »
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline thomaspigeon

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Re: About to start my project, but it doesn’t...
« Reply #10 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...

Offline Nurse Julie

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Re: About to start my project, but it doesn’t...
« Reply #11 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.
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline deltarider

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Re: About to start my project, but it doesn’t...
« Reply #12 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.
« Last Edit: September 07, 2020, 07:03:02 AM by deltarider »

Offline Seabeowner

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Re: About to start my project, but it doesn’t...
« Reply #13 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.
Phil
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Offline Macabethiele (Ted)

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Re: About to start my project, but it doesn’t...
« Reply #14 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 .
Honda CB400F2 under restoration
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Mercedes R129 SL500

 

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