Topic: Hello and my CB550 is running on 2 Cylinders

[Pltfn]

Hi Guys,

This is my first post here so I will introduce myself.  My name is Kelly and I am from Golden Colorado, USA.  I was browsing ebay a couple of months back and found this beautiful CB550 with full BCR tank, seat and battery box.  It was painted the most beautiful gold and seamed to me perfect in every respect.  Well, instead of being rational and just buying it and having fun out of the box, I decided I could save a thousand or so dollars and build one myself.

So here I am, waiting for my tank and seat from Benji.  I have redone the exhaust in a Yoshimura Copy (see Carpy's website) kind of way but in bright white.  Rebuilt my forks. Drilled my engine cover. Pulled the oil pan for inspection...  You get the idea, I have been covered in oil and dirt for the last month. 

I finally got her back together enough to start and charge the battery and cure the Exhaust paint last night...  Well, she is now only running on the left 2 cylinders (when viewed from sitting on the bike).  She was running really well before I started my work and I didn't touch anything that has to do with fuel or spark...

I belive that the ignition sytem is the culprit.  The carbs where fine a week ago when I took her off the road, I have no reason to think that they wouldn't be fine now.  I think I may have blown a coil when I arced the battery to the frame while removing the seat lock, is this possible?  Also, from reading about coils on this site, I noticed that one coil is for cylinders 1 &3 and the other is for 2&4...  A blown coil doesn't really jive with her now running on her two left cylinders.  What do you think?

I know what you are thinking, he wants help but doesn't even have any pictures of his progress on this post...  I know, I promise to put some up when I feel like I have made a bit more progress!

-Kelly

[mlinder]

It prolly carbs.
And no, if ti was ignition, at least from points back, it would be either 1 and 4 that dont fire, or 2 and 3. Not 1 and 4. You didn't swap the wrong plug wires, did you? between 1 and 2?

[kslrr]

Welcome to the site.

Your right about the coils.  If one coil was bad you'de be running on cylinders 1&3 or 2&4.  Maybe there's the possibility of 2 bad plug leads at once?  If you have a salvage yard near you, find some extra coils and try swapping them out as one meathod of trouble shooting.

[Pltfn]

I will check my carb bowls for gas.  I would have expected the bike to fire up like normal but then cut out if I have a fuel delivery problem (remaining fuel in carbs from previous running would burn off then it would cut to 2 cylinders)...

I don't have a salvage yard near me (as far as I know).  I will have to bench test the coils...I remember seeing a right up on this somewhere here.

Thanks guys!

[Laminar]

Welcome to the site.

Your right about the coils.  If one coil was bad you'de be running on cylinders 1&3 or 2&4.  Maybe there's the possibility of 2 bad plug leads at once?  If you have a salvage yard near you, find some extra coils and try swapping them out as one meathod of trouble shooting.

My CB550 has one coil for cylinders 1 and 4, and one coil for cylinders 2 and 3.

Most auto parts stores sell a spark tester - you insert one end in the plug wire boot and the other end is a clip you can attach to the engine fins for ground. It makes testing for spark easy.

[Laminar]

Cylinders 3 and 4 (numbered from left to right sitting on the bike) do share a fuel line, so checking the fuel level in each carb bowl is a good idea.

Recheck your plug wires, too - make sure the wires from 1 & 4 go to the same coil and 2 & 3 go to the same coil (again numbered from left to right sitting on the bike).

[noobie dave]

Clean the hell out of your carbs and make sure the air intake system is sealed up good.  I was having problems with 1 and 4 cutting out at higher RPMs; after I sealed up the intake boots and cleaned the "slow jets" I didn't have the problem anymore.

But yeah, you might want to troubleshoot the ignition system first.

[Pltfn]

Excellent, Thanks.

I will let you know what I find.

-Kelly

[Zaipai]

Yea, if the bike was running before you started your work, and it has not been sitting too long its probably the ignition, real easy to have the spark plug wires on the wrong plugs (cough  ) and its an easy thing to check, if not then go after the carbs, fuel line etc.

GL and Welcome to the Forum!

[Pltfn]

Thanks for the Welcome!  I am really puzzled because I literally didn't touch the ignition system or fuel system.  I have previously not ridden it for week intervals with no issue, starts right up with the first kick.  This time the only difference is that I did some work to the bike (all cosmetic and suspension).  I will check the wires just for good measure though!

-Kelly

[Zaipai]

Yeah, that is a an odd thing. Well start someplace and keep going till you find it. If it is the carbs they may have just had the dirt and gum finally clog the carbs.. Wont know till you get moving on it. Keep us in the loop..

[Pltfn]

Well Guys...

Last night I pulled my spark plugs for cylinders 3 and 4 and checked them for spark.  Both had spark, so I am good there.  I noticed that they are covered in black carbon and I likely need to tune the bike, but I will get that done after the cosmetic work is done (one thing at a time).

So it had to be a fuel problem...

I turned the screw on the bottom of the float bowl and got a few drips of fuel, so I thought "well, it has fuel"... but then the drips stopped .

I am absolutely embarased to say this, but it occured to me that the bike was getting pretty low on gas the last couple of times I rode it.  I opened the gas cap and shook the bike around vigerously and couldn't even hear a single drop of gas jumping around in there.

So long story short, I was out of gas .  I now know a little more about my bike (I am absolutly new to this, have only been riding/had a bike for less than 2 months).

Sorry About the anticlimatic ending! Thanks everyone for the help!

-Kelly

[Laminar]

Good to hear that it was something easy.

[KCRSXTypeS]

Well Guys...

Last night I pulled my spark plugs for cylinders 3 and 4 and checked them for spark.  Both had spark, so I am good there.  I noticed that they are covered in black carbon and I likely need to tune the bike, but I will get that done after the cosmetic work is done (one thing at a time).

So it had to be a fuel problem...

I turned the screw on the bottom of the float bowl and got a few drips of fuel, so I thought "well, it has fuel"... but then the drips stopped .

I am absolutely embarased to say this, but it occured to me that the bike was getting pretty low on gas the last couple of times I rode it.  I opened the gas cap and shook the bike around vigerously and couldn't even hear a single drop of gas jumping around in there.

So long story short, I was out of gas .  I now know a little more about my bike (I am absolutly new to this, have only been riding/had a bike for less than 2 months).

Sorry About the anticlimatic ending! Thanks everyone for the help!

-Kelly

AHAHAHAHAHAHAHA That same thing has happened to me a few times...

[Zaipai]

Well Guys...

Last night I pulled my spark plugs for cylinders 3 and 4 and checked them for spark.  Both had spark, so I am good there.  I noticed that they are covered in black carbon and I likely need to tune the bike, but I will get that done after the cosmetic work is done (one thing at a time).

So it had to be a fuel problem...

I turned the screw on the bottom of the float bowl and got a few drips of fuel, so I thought "well, it has fuel"... but then the drips stopped .

I am absolutely embarased to say this, but it occured to me that the bike was getting pretty low on gas the last couple of times I rode it.  I opened the gas cap and shook the bike around vigerously and couldn't even hear a single drop of gas jumping around in there.

So long story short, I was out of gas .  I now know a little more about my bike (I am absolutly new to this, have only been riding/had a bike for less than 2 months).

Sorry About the anticlimatic ending! Thanks everyone for the help!

-Kelly

I am glad if thats all it was then its a good thing. Don't appologize for over looking it. If we all started doing that the forums would be filled with appology's and fewer content!