Topic: Post hibernation 76' CB550K starting issues

[WJL75]

Finally there is some nice weather here in WI, and had my bike out last week for a quick ride. 

It started after a a few minutes of kicking and screaming, nothing bad after a long winter hibernation...but #1 header was not warming up when idling.  Pulled the float bowl on #1 and it's as clean and shiney as can be with no deposits at all. 
 Checked the spark plugs and there is spark on each of them.

After the ride, #1 was as hot as the others, and the second ride the next day it fired right up and was warm when idling.  Fast forward to yesterday and it will not start. 
It did start for about one minute last night, and idled, but would not respond to any throttle.  I checked the cable and it clearly IS moving the carbs when the throttle is opened.

What should I look for next?  I've never had to adjust the timing before, but it seems the most likely culpret for me.  The only weird thing is that it seemed to run fine last week.

[bryanj]

Has it run out of gas?

[WJL75]

Plenty of gas in the tank...I'd guess about 3 gallons left.  Even tried flipping the petcock to reserve.  While I had the float bowl off on the #1 carb, I checked gas flow into it while in both positions, and it was fine.

[Gordon]

Battery fully charged?

[WJL75]

The battery was on a tender all winter.  After a half hour of trying to start it, I put it back on the tender for about 4 hours until the light was solid green again.

[Johnie]

Even with the timing out a little it should respond to throttle.  Almost sounds like a fuel issue to me.  How about maybe some dirt got into a jet or 2 or floats hanging up a bit?

[WJL75]

I was hoping not to have to pull the carbs, but I guess that is the next step.  Too bad, as it is going to be near 70 here today, and my new KLR 650 does not come in until next week, so I am rideless.

[bikehenge]

drain the fuel into a fuel can and use it in your lawn mower (or in your case: snowblower? ha).
Put fresh gas in the tank and try again,  you might also use some SeaFoam fuel system cleaner.

At this point your plug may be dripping wet so a fresh plug may be helpful.

Rob

[TwoTired]

If the carbs were as clean as you say, I'd pull out the spark plugs and look at them, if not change them out right.  The center electrode insulator should be tan, not black.

With the carb bowl off you can easily remove #1 slow jet (while the carbs are still on the bike), and see if light will pass through it.  Evaporation can leave deposits in that tiny orifice.

Cheers.

[WJL75]

I had seafoam in with the gas all winter.  I will try that tonight.  Thanks for the ideas everyone.  Keep em coming.

[WJL75]

If the carbs were as clean as you say, I'd pull out the spark plugs and look at them, if not change them out right.  The center electrode insulator should be tan, not black.

With the carb bowl off you can easily remove #1 slow jet (while the carbs are still on the bike), and see if light will pass through it.  Evaporation can leave deposits in that tiny orifice.

Cheers.

I'll take a look at them tonight after work.  I have a nice set of old guitar strings for just this reason.

[WJL75]

Looking over the Clymer manual it say basically to remove the slow jet...  Can anyone here elaborate as to how (without breaking it)?  It there a pin, or is it screwed in place?  I did a search within the site but found nothing specific.  Keep in mind I'd like to leave the carb rack on the bike.

[TwoTired]

On the 76, the slow jets unscrew.  Correct length screwdrivers are most helpful. As are inspection mirrors to see what you are doing without shrinking your head.

Note how much torque you use when removing, and use the same to reinstall. Use too much torque and they break off.  This causes blue words.

Cheers,

[WJL75]

Thanks TT.  I will try this out tonight after a stop at Ace Hardware for a mirror.  I've said it before and I'll say it again...this site is fantastic.

[76 cb550]

I don't think the guitar wire is a good idea. 

It's steel isn't it.  Everything I've read says to use a single strand of multi-stranded copper wire.  The steel can widen the hole on the jet.

NOTE: not everything to be honest...some things say not to use any wire.  Use compressed air instead.

[WJL75]

I'll take a look, you may be right.  I know I have some wire that is definately copper around somewhere too.

[TwoTired]

I don't favor guitar strings, but I have used them once or twice.  I rounded off the pokey ends to prevent scoring the soft brass.  It's also good to know your wire is smaller than the orifice you are clearing.  Jamming an 0.018 wire in a 0.016 hole is not good.  A 0.009 or 0.010 string should allow the pressurized carb cleaner to do the finishing job.

Cheers,

[WJL75]

I checked #1 and #4 slow jets,  Slow jet on #1 was clogged.  I need to still look at #2 and #3 tonight when I get home and can get some better lighting. 

Looked the the plugs and #1 was cabon fouled, black and oily.  The others were a little cabon fouled...definately not tan. Could this be due to repeated failed starting attempts?

While inspecting the in-line fuel filter, I noticed that the fuel line is just starting to crack (I saw one small one starting), so that is getting replaced today, along with at least one of the plugs and the in-line fuel filter itself.  Should I just replace all of the plugs while I am at it?  They were all new last year.

[Johnie]

Sounds like you are finding the problem.  I install new plugs every year.  They are cheap enough and how she runs depends a lot on those plugs.

[TwoTired]

Looked the the plugs and #1 was cabon fouled, black and oily.  The others were a little cabon fouled...definately not tan. Could this be due to repeated failed starting attempts?
Should I just replace all of the plugs while I am at it?  They were all new last year.

Prolonged idling and/or choke operation can foul spark plugs.

The plugs need to get to a temperature where they will self clean unburned combustion deposits.  (assuming fuel mixtures are correct)  The chambers burn rich and cool during idle and cold weather draws combustion chamber heat away rapidly with those big cooling fins on the motor. (The fins are designed to save the engine from overheating while driving flat out on hot weather.  So, it is over-cooled in other situations.)  Of course, choke dumps extra fuel in the chambers.

If your carb mixtures are correct, the plugs should self clean when you get it wound up on the freeway for 15-20 minutes.  In other words, make the engine work hard and make heat to burn off that soot.

Or, perhaps the cost/benefit ratio is a better option for you to simply replace all the plugs?  How much is a nicer running engine worth to you right now?  Would you rather ride or tweak on the bike?  Is money tight?  I don't know your whole situation.

Cheers,

[WJL75]

Thanks for the input TT.  I replaced the fuel lines, filters and plugs, and she's a one kick bike again!  That first ride felt good.  Idles fine and other than needing to add some fork oil (no sign of leaks, just seems soft to me) she runs like she's in top form.

Thanks again to all for your help and assitance.

[TwoTired]

Sounds like a job well done!

Keep the rubber side down, OK?  And have fun!

Cheers,