Topic: Starting Problems CB550

[Wollongongwolf]

Hi all, just a question before I take the bike to the mechanic as I would like to try and sort this myself first.
Been having problems and getting worse trying to cold start my CB 550. I thought I may of been flooding it and I did all the usual tricks to get it started, no luck.
Decided to pull out the plug to see if it was wet and fouled. To my surprise they were dry, but had heavy black carbon. Took all four plugs out and we're all the same. Cleaned them up, bike started straight up.
So with my lack of knowledge, it would appear the bike is running rich, so any pointers on adjusting carbs to make them a little leaner maybe?
The bike seems to be running fine when riding, so what else may be causing this? I run standard 91 octane fuel with with lead replacment at 1%.
Any help would be appreciated.

[streak09]

Hello there. First off, no need to run high octane. Only high compression engines can take advantage. I would first try that and see how it acts. I think that could be attributing to your fouled plugs. Have you check plug gap as well?

[DaveBarbier]

What is your intake/exhaust setup? So it used to start ok but lately it's been an issue? Do any modifications recently?

Are you trying to start the bike with the choke engaged? What happens if you don't use choke at all?


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1978 Honda CB550K

[Wollongongwolf]

Thanks for the replies. Not using hi octane fuel, 91 is normal fuel here, 98 is the highest. Also not using E10 ethonel. Bike always started fine, done no modifications at all. I use about half chock to start, usually turn fuel off on a cold start so not to flood. Done that with all my Carbie bikes since I was a kid. Always seems best way to go.
Not checked the plug gap, is how they came from the box.
So it wouldn't be a mixture thing? Should I try adjusting carbs?

[flatlander]

i guess you're in europe where 91 RON (referred to as "octane") is indeed "regular" pump gas?
most people on this site are in north america where octane rating uses a different scale. 91 octane there would be 95 RON over here, so closer to our 98 RON.

check the plug gap to be sure. and maybe post a picture of the plugs?
and try what dave says, cold starting without any choke.

why do you need to turn off the fuel for a cold start? are your floats not working?

[DaveBarbier]

Plugs should be gapped according to the manual. If your bike is completely stock with stock jets in the carbs and it always ran fine before, I'd avoid changing any carb settings. Maybe I'd drop the carb bowls to look for any debris. It is possible that your carbs need a thorough cleaning. But first thing I'd do is the 3k mile tune up. Plug gap, cam chain, valve tappets, point gap, timing. And, because it's an easy test, I'd check the resistance of the coils, plug wires and plug caps. Can't have a good running bike with a weak spark. Please post the OHMs readings after your tests.

EDIT: And I'd test your battery, too.

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1978 Honda CB550K

[Wollongongwolf]

Carbs were rebuilt 3000 kilometres ago, cleaned the plugs up to get her running and running fine again. I will replace the plugs and check the gaps, keep an eye on them, see what happens. Getting complex for the worlds worst mechanic.
Was thinking about getting rid of the points and replacing with electronic.
Sounds like a job for my old school mechanic.
Thanks for your advice.

[DaveBarbier]

You're welcome. But I'll reiterate that I think you should do the tune up that I listed and check the coils.
Good luck


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1978 Honda CB550K

[calj737]

But I'll reiterate that I think you should do the tune up that I listed and check the coils points and condensers.

My $0.02 piggybacked on Dave's sound advice

[Wollongongwolf]

Thanks, to complicated, will take it to the mechanic , tell him the problem , get it all checked out. By the time I finish working it out, better paying him.
Done 3,000 klms since I got it running and on the road, so would be due for a tune up.

[Deltarider]

First off, no need to run high octane. Only high compression engines can take advantage. I would first try that and see how it acts. I think that could be attributing to your fouled plugs.

Interesting. Why do you think that?

[streak09]

First off, no need to run high octane. Only high compression engines can take advantage. I would first try that and see how it acts. I think that could be attributing to your fouled plugs.

Interesting. Why do you think that?

Well, let me preface that my knowledge is not deep in the subject, but I know the basics.

Higher compression engines are the only ones that can use the higher octane level of the premium fuels. Higher octane fuels can withstand higher pressure before detonating, hence the use in high compression engines. If regular gasoline is used in high compression engines, you will get pre-detonation because it detonates at lower compression. This is not good for performance nor mileage (or engine life).

Running premium in a standard engine wont damage it, but it has 0 advantage (unless you are getting "pinging" from pre-detonation) so you are basically throwing away money. The fuel may not burn efficiently which may result in carbon deposits, therefore fouling plugs.

That's my thoughts behind it...

EDIT: It sounds like he is not using premium fuel though

...Not using hi octane fuel, 91 is normal fuel here, 98 is the highest. Also not using E10 ethonel...

so my initial theory is out the window. I am not versed in international fuel ratings, typical American 

[calj737]

That's my thoughts behind it...

And you are 110% correct.

[Deltarider]

The fuel may not burn efficiently which may result in carbon deposits, therefore fouling plugs.

It's crap. High octane fuel BURNS just as good as regular. Maybe it's time for you to become more 'basic' and have explained the difference between detonating and burning instead of echoing wrong ideas.

[calj737]

It's not about "burn", it's about its compressible nature. The higher the octane level in fuel, the more the engine must compress the air/fuel mixture to extract the energy from the fuel. If you had read his statement completely, and looked to understand what he wrote as opposed to seek an opportunity to "opine your anecdotes" you might have realized where you're incorrect.

[Deltarider]

It's not about "burn", it's about its compressible nature. The higher the octane level in fuel, the more the engine must compress the air/fuel mixture to extract the energy from the fuel.

Oh boy, oh boy, it's back to school for you too and learn about what detonation means and what burning is. If you think it's all the same, you get this kind of nonsense. 'Extract the energy', don't make me laugh with your poetry...

If you had read his statement completely, and looked to understand what he wrote as opposed to seek an opportunity to "opine your anecdotes" you might have realized where you're incorrect

.
I have read it well and for "opine your anecdotes" we have you.

[streak09]

The fuel may not burn efficiently which may result in carbon deposits, therefore fouling plugs.

It's crap. High octane fuel BURNS just as good as regular. Maybe it's time for you to become more 'basic' and have explained the difference between detonating and burning instead of echoing wrong ideas.

It seems that the original intent of this post has been met. If it hadn't, I wouldn't derail it further by replying to you Deltarider, but since it has I will .

I knew good and well that you were fishing for an opportunity to unleash your "Holier than thou" attitude and make me feel inferior next to your watermelon sized head when you inquired about my statement. I've read enough of your replies to know what was coming. I thought about not responding, but knowing that the original poster had gotten the information he was after and had made his decision, I decided to cast my line and go fishing myself. I caught a big melon-headed-ass fish.

You can pick apart my statement as much as you want, I think most of the readers understood what I was trying to convey. If you are right, no one will listen because of the way you choose to respond. Maybe its time for you to become more of a 'basic' person and not dissect every statement just to point out a single flaw and discredit everything that has been said. I think you would find people will receive and welcome your knowledge. Or... you can remain a big melon-headed-ass fish, its your right, and if you want to, to each their own. I'm sure others will enjoy catching and watching the ass fish flop around in all its big-headedness.

I'll lay it out for you because you will probably pick at little sections of my rant: You make an ass of yourself.   

This is my first and last response to such a bigoted post. I don't have the time to waste on such unproductive clatter. I would rather constructively add to the forum with those who respect and civilly dispute their stances.   

[calj737]

it's back to school for you too

No thanks, I've got enough degrees and initials to satisfy me.

I have read it well and for "opine your anecdotes" we have you.

I'll let this pass since you are fighting in a non-native language.