Topic: What can I do while I wait...1976 CB550k

[Nortstudio]

Ok folks.  You all have helped me through some early issues, and I am extremely thankful.

Next up, I have some issues that have me scratching my head.  Please excuse the long post...

History: Seller was less than diligent about maintenance. Came with 4-4 exhaust; one muffler missing, 2 more rotted/rusted through.  Last one shabby at best. Weird thing is that it ran fairly well, although I couldn't really hear the engine very well. Acceleration/Performance was fairly smooth. I recall it burning liquid off all four headers equally (half assed heat test - don't ask about the liquid .

My moves: I replaced the exhaust with a 4-1 (thanks Tango for this and all the help).  First thing i noticed was that there was a "ticking."  Then I started noticing that there was hesitation around 3000RPM - most notably in 2nd gear.  If I twist the throttle quick, it scoots right thru the hesitation, and has a bunch of giddy up.  From everything I've read & heard, seemed to be running lean.

But then, next I changed the spark plugs.  Rode it for a bit, and noticed the #4 header was not as hot as the other 3.  Checked the plugs (photos below) and every one of them was different.  Most notably, the 4th plug was cleanish (less typical deposit looking stuff) but had oil/moisture on it.  The other three were various states, #1 looking about as perfect as I can tell from web photos.

My next step will be to check the valve clearances, and timing.  Unfortunately I will need to wait on the proper tools.

My question is this: is there anything I should check before getting right to the tuneup process I have read about here? I know that I need to do plugs, timing, valves and then carbs.  But is there something I can be doing while I wait for the tools?

Appreciate your consideration.

#4 oily

darkest of the bunch...

leanest of the bunch...

best looking of the bunch...


  

[seaweb11]

Seems to be running lean and rich and hot and cold, all at the same time?
I can't remember, did you do the complete carb clean rebuild yet?

[dave500]

the lean ones might have a vacuum leak?get the carbs apart and spend a few days on them.,check the plug caps resistance,or just buy new ones.

[TwoTired]

My moves: I replaced the exhaust with a 4-1 (thanks Tango for this and all the help).  First thing i noticed was that there was a "ticking."  Then I started noticing that there was hesitation around 3000RPM - most notably in 2nd gear.  If I twist the throttle quick, it scoots right thru the hesitation, and has a bunch of giddy up.  quote]

The ticking is probably and exhaust head to header leak.

I'd defer working the hesitation until after the complete tuneup and carb sync.

Do check the tank for rust/crud and verify that the filter is intact.
Take off the float bowls and look inside for sediment/gum.  Or, just drain the contents of the bowls into a clean pan.  Any specs of "stuff" larger than 0.016" spell pilot jet stoppage.  Can't "tune" that out.

Is your air filter stock?

Cheers,

[Nortstudio]

Sorry, should have stated:

No carb overhaul yet.  I JUST got an exhaust going

Stock air box setup, with replacement filter on the way.

I put the exhaust on with the new gaskets, seemed to fit ok, and there is no obvious air leaks.  Would these be so tiny I wouldn't feel it?

The spark plugs are brand new.  What does the reference to plug resistance mean?

I did the test spraying wd-40 around the boots to see if there was a change in rpm.  No change.  Am I doing this test wrong?

I will be moving on to the carb sync, but seemed I should have the timing and valves correct, based on the methods I have read here.  Does that still make sense?

Thanks for your reply folks!

[DavePhipps]

Take carbs off and do a complete cleaning. remove all jets and clean them. I used a strand of copper wire to clean mine out. Then blasted the jets with carb cleaner and then with 100PSI air. I then did the same for all pasages in the carbs themselves.

While you have the jets out, check the sizes. You have a K bike wich came with a 4-4 and are now running a 4-1. I think the 4-1 requires a 100 main jet at least. I would check the carb FAQ for that info. TT can verify if he would like to.

Like others said check for air leaks at all carb connecters and airbox, and check plug wires and caps
My other advice after doing all of the above is, adjust valves, set points, check ignition timing, sync carbs.
All of the above effect how you bike breathes and burns fuel. Unless it's all set correctly you might end up running in circles trying to diagnose this. Unfortuantely this statement comes from personal experience. Don't ask, it's a long embarrassing story.

[Nortstudio]

Thanks Dave.  Can you tell me how to test the plug wires and cables?

Also, what's the best test for the air leaks near the carbs/air box?

[DavePhipps]

I can't remember off hand, and don't have enough time to do a search. I'm getting ready for work.
Somewhere on the site it tells what values you should get when testing caps, wires and coils with a multimeter.
You're already doing what I would do to check for leaks.

[Nortstudio]

Thanks dave.  I will search some more, I'm sure I will find it.  Appreciate all the help.

[TwoTired]

I put the exhaust on with the new gaskets, seemed to fit ok, and there is no obvious air leaks.  Would these be so tiny I wouldn't feel it?

Yes, it let's the sound escape.  The end of the header must be supported at or near it's final position before the head bolts are tightened.  If not, the gaskets crush unevenly, leading to leaks.  You can localize the "tick" source by using a piece of aquarium tubing, and using it as a sound guide.  One end goes in the ear canal, the other end is used to "probe" the sound source.  When the probe gets near the source of the sound, it gets louder.

The spark plugs are brand new.  What does the reference to plug resistance mean?

If there is an R in the plug's number.  It is a resistor plug.

[Duanob]

tsk, tsk! Do the 3000 mile tune up FIRST before the carb tune ALWAYS! Then see how she runs. After that when you have the carbs off, pull your intakes off, it takes a few minutes and replace the intake gasket O-rings. they are cheap and after 34 years get brittle and crack. They are the same size as the tappet cover O-rings. Check you carb boots off the intakes to make sure they don't have any cracks or holes. Clean everything and reinstall. That should be about it for vacuum leaks from carb to motor.

Plug caps, make sure they fit tight on the end of the plug wires. They screw on and off. If you need to, cut a bit off the end of the wire and screw the caps back on.

Let us know when you get to the carbs and we can walk you through that process.

I have the same bike and have been through a bunch of this already.

[DavePhipps]

How to test plug boots/caps

http://forums.sohc4.net/index.php?topic=66828.0

[dave500]

a cheap digital multi meter will be needed to test the resistance of the actual spark plug caps,they unscrew from the wire,dont use plugs with an "R" in the number these have restistance,read the manual with the cheap meter youll need to buy if you dont have one,,itll come in handy further down the track when you start to ask about charging and indicators not working maybe.

[Nortstudio]

Thanks guys!  

Dave, Thanks for the plug link.  TT mentioned "If there is an R in the plug's number.  It is a resistor plug."  The new plugs I put in are NGK D7EA with the number 7912 on there as well.  So since it has no R, am I skipping the test?

Duanob: I am definitely planning on doing the 3000 mile tune up, just waiting on the right tools.  I was just looking for some things I might be able to do before they arrive (could be middle of next week, with my luck!).  The list i have read a few times here (and has been suggested by friend/member Steve) is that I should do timing, valves and then get to the carbs last.  

I also wanted to make sure I had the exhaust correct, since I figured ALL things are related (starting to gibe me a headache) and before I had basically 4-1, but with a 4-4 exhaust  Seems i might need to order new gaskets for the exhaust pipes again too - if i did as TT mentioned and lined them up a little off when tightening.  Ugh!

I'm fine with all this, except right now, enthusiasm running hot, patience running cold, like the plugs

Appreciate all your time folks.  I'll let you know how I make out.

[Nortstudio]

Quick Plug gap question.  The manual I downloaded stated that the plug gap should be .024-.028.  I made them right in the middle.  There is a data sheet from Old Man Honda that lists the same year/model should be .028 - .032.  Which is best?

Thanks.

[DavePhipps]

The plugs you have are a non-resistor.
While waiting, some things you could do are work on tidying up the headlight wiring. Cleaning all electrical connctors and coating them with some dialectric grease.
Check and regrease bearings where needed. Lubricate all cables, adjust and lube chain.
Check regultor and rectifier for proper operation. Basically check all the little things that can cause issues down the road.

About plug gap, I'm not really sure, but I like your approach.

[Nortstudio]

Thanks dave, that's about where I was netting out. 

There are plenty of things that I can do to tidy up this baby (rather unattractive baby at that!).  I'm just all hot to trot because there are so many things to do, and it's pouring rain outside.  My workshop is the curb in Brooklyn, so i try to get all my ducks (read; knowledge) in a row before I head down to attempt anything new....which is EVERYTHING right now

I have some of the things I need already for some of your suggestions, and that's where I will start once the weather stops being ornery.

[Duanob]

Add to Davephipps list check your fork seals and replace your fork oil. If your gators are torn or missing you can bet you will be tearing down and rebuilding your forks. Not a hard job and nice knowing it's done. Also the headset bearings need cleaning/regreasing/replacing. What about your brakes? They need to be working properly before you ride the thing. Rebuilding the master cylinder and replacing the caliper piston seal should be on your list unless it's been done. Lots to do!

[TwoTired]

Quick Plug gap question.  The manual I downloaded stated that the plug gap should be .024-.028.  I made them right in the middle.  There is a data sheet from Old Man Honda that lists the same year/model should be .028 - .032.  Which is best?

If you are using the stock ignition and coils, Honda would seem to be a good reference.
I've been gapping my Cb550 plugs at .025" since 1975.
I haven't won any GP races.  But, I like to think they just lost my entry form.

Cheers,

[Nortstudio]

That's exactly where I set it.  Good to know I'm not so far off...on some things

They'll find that form someday....someday.

[Nortstudio]

I'm was already on the brake tip too.  Got started with that first - before I even had the exhaust.  Seemed to be the safest place to start.  Only trouble there was the damn rusted/frozen bleeder.  I'm trying to check things off the list.  It's pretty long, and seems to grow longer each 10 minutes I sit and stare at the bike....  Pretty fun though, and the learning has been less painless, due to all the help here.  

Thanks again.

[DavePhipps]

I'm with ya Nor. My garage is a patch of gravel under a tree.

[Nortstudio]

But, oh how the neighbors love my oil spills

[TwoTired]

You could ask to borrow a cup of kitty litter from the neighbors...






 

[Nortstudio]

Bought my own.  A bunch in fact. Thinking about getting a cat!