Topic: Recently purchased a 75' cb550 and need help diagnosing some problems

[Conrad1867]

Hey guys:

Just purchased a 75' cb550 w/ 23k and a clear title from a farm in Michigan.

The electric start was working for about a day and now it won't turn over.  There's just a clicking sound from the starter and sometimes not even that.  The lights and horn sometimes work and other times, when I go to turn the lights on, the power cuts out.  I think it is an underperforming battery.  I've resorted to kick starting it everytime since.  The electric starter button and battery were replaced in the past year.


Also, taking it around the block, the bike dies out every time I slow down to take a turn (I have the clutch pushed in and am switching to a lower gear).  If I don't rev it with the clutch pulled in while taking the turn it will not be running at the end of the turn.  Therefore, I have to kick start it, to get it going again. 
This also occurs, if I attempt to lower the choke while I'm warming up the bike.

I was told the carbs were cleaned within the year and have personally checked that the oil is fresh and new. 

I'm not really sure, what to change besides buying and installing a fresh new battery.  However, I feel like this may not be enough to remedy the situation.


Thanks for any suggestions,

Conrad

[Johnie]

On the easy side, what is the idle RPM set at?  If you are lucky you will just need to set it a bit higher so it will not quit when you let off the gas.  Keep in mind just because he said the carbs were rebuilt a year ago...there are a lot of "stages" to the words "rebuilt carbs."  Maybe he just ran some carb cleaner through...who knows for sure.
Clicking starter could be a low battery or solenoid problem.  Did you pick up a service manual yet?
A good start is to get a new battery that way you know where you are at and can go from there if needed.  Good luck with your project.

[OldSkool]

If I had to guess I would say you probably need to rebuild the carbs yourself. The idle jets on these bikes are a sore spot and clog easily. This could explain why the bike dies at lower RPM's.

[JS550]

A friend has a cb1000 that did the same thing. It was the battery.

[Philly550K1]

hi. welcome to the madness. searching this site will catch you up quickly on common issues and the variety of approaches to same.

assuming you're not the type to just tear into everything and baseline the systems according to the manual (and only a cocky, and/or experienced, and/or masochistic mechanic would do that to a running bike in may, imho...  ...)

my recommendations/opinions (heed them, this is tha interwebs talking):
1) do one thing at a time and observe the effects of each on all your symptoms  2) place "tearing into the carbs" as far down on the list of things to try as you can, after you've baselined the electricals and gotten the valve clearances and compression verified.

a fresh battery isn't the worst step to take.  but i would at least charge the one you have, and take a voltmeter to it with the bike running, to see what voltage you get across the terminals at what rpms. that will be a useful clue before you go taxing a new battery.

start with battery, move to idle setting, continue reading here....

-jon

[Conrad1867]

Thanks for the suggestions.  A friend is dropping by tomorrow with a charger.  I'll start with the battery and go on from there.

How hard is it to mess up a valve clearance adjustment and the like?  That's my low confidence talking..

Thanks,

Conrad

[Johnie]

Thanks for the suggestions.  A friend is dropping by tomorrow with a charger.  I'll start with the battery and go on from there.

How hard is it to mess up a valve clearance adjustment and the like?  That's my low confidence talking..

Thanks,

Conrad

You should be able to do the valve clearance adjustment if you follow the service manual.  It will tell you where the crank needs to be in reference to valve positions for checking them.  You move the crank by the large bolt where the points are located.

[Conrad1867]

Hey guys:

Update time:

Battery charged for over 13 hours on a charger.  The electronic start starts up the bike now, though if  the bike has sat for a while, it still takes some time to turn it over.  So it was an undercharged battery after all.

The problem of it dying continues to persist however. 

[Philly550K1]

let's stick with the electrical for a minute. you should still put a voltmeter on the battery while it's running. even an el cheapo one, set to the "20v" range, red to red, black to black. if you aren't getting well over 13v, your battery isn't charging while the bike is running. if it's running down the battery, there isn't enough juice to fire the plugs strongly at low revs. (trust me -- these issues interrelate in ways you will begin to understand...)    even healthy, the stock setup drains the battery at idle, more so with lights on....

jon

[TwoTired]

You wouldn't happen to be afraid of engine RPMs, would you Conrad?

With the lights on, a normal 550 won't even begin to charge the battery until about 2000 RPM.

The electric starter draws power out of the battery about 120 times faster than the alternator can put the power back into the battery. If you use the electric starter for, say 30 seconds, you'll need and hour or more on the freeway to restore the battery to full charge.  If you can turn off the head light, it will recharge faster.

Each time you idle at a stop light, the battery loses stored power.

This assumes a 550 that has all good electrical components.

[Conrad1867]

Another update:

Decided to buy an "AGM" battery since I've read a lot about them on this forum.  Ended up getting the AGM 2 extreme because the regular non-maintenance Extreme would have had the terminals inwards, away form the cables.  20 bucks extra, but the guy was a bike dude and he gave me 10% off.  Plus a 2 year warranty isn't too bad either.

Good news - Bike starts up instantly with the electric start as compared to the other battery. 

Bad news - the bike still occasionally dies.  I'm beginning to think it might be a clogged fuel line or even worse (Because I don't think I can do it) - it might be the carbs...

I've ran some Sea Foam after topping off using Shell Premium without much visible improvement...

I've read that going at the carbs should be a last resort and I would like to avoid them....

Any ideas and or suggestions are, as always, very appreciated.


Thanks for reading,

Conrad

[TwoTired]

Scheduled maintenance (tune-up) is 3000 miles/3 months whichever comes first.

It's hard to get sympathy from me about run issues, until meeting the scheduled maintenance requirement.

After that, then look into the carbs.

You can still check for tank internal rust.  Or, drain and catch each carb bowl's contents into a clean container.  If there is any non-liquid material floating around inside the carbs that can't fit through a 0.016 inch hole, you will have idle/slow/pilot jet problems.

[WFO]

You have to eliminate possiable issues before you can proceed, i would clean every electical connection and everything from top to bottom and tune up as TT said you might be opening up a long process of future problems when you can fix them before they start.

[Conrad1867]

Hey guys:

The madness continues.

Sorry that I haven't posted for a while, but unfortunately, one of the 35 year old throttle cables decided to break so I was waiting for the parts until today.

Now that the throttle is back in working order...

I bought an O.E.M. air filter and glad that I did.  Comparison wise the new one was the color of icing on a white wedding cake compared to the old sewer colored one.

New spark plugs as well - NGK D7EA's.  The old ones had a moist dark residue on them.  Does this mean too much gas?

Also checked the gap clearance after taking off the break point cover and it's at .35mm so that's fine too.

The problem of it dying at a stop light continues...

Kill me,


Conrad