Topic: yet another newby with dumb questions

[cb550gwdsc]

1977 cb550 F.  It ran pretty well when I got it in April but gradually got worse (that feeling when you know you just got bad fuel).  So I decided to just go over all of it.  Here is what i've done so far:

new plugs and wires
new ignition coils
new points, condensers
new air filter (stock air box)
new boots from air box to carbs
rebuilt the carbs and synched
static timed
points gapped along with tappets gapped
cleaned the tank (it wasn't too bad)
new fuel lines and filter
changed oil and new oil filter

It idles fine but wants to surge a lot when you get over 3 or 4000 rpm.  And backfires some too.  I feel like its a carb issue but not sure what to do next.  I've taken them off 2 times now and gone over them but feel like I did a pretty good job rebuilding them.  Very clean inside and out.  And i've searched the forum but nothing seems to jump out at me.  Fire away please.
thanks

byron

[78whiteorbs]

Does the idle hang any when revved at idle.
spray around intake boots(between carbs and engine) with carb cleaner when she is idling and see if rpms increase any. If so tighten or replace clamps and check again
Did you check the spark advance with a timing light?
Check on startup thst all headpipes are heating up...if you can touch once longer than a a wee bit it might not ve running on al fours or you could have a carb gutting in and out . check float bowl levels using clear tube method.

Thatll give you a little ammo-

[jgger]

What brand points and condensers did you get?

[cb550gwdsc]

Does the idle hang any when revved at idle.
spray around intake boots(between carbs and engine) with carb cleaner when she is idling and see if rpms increase any. If so tighten or replace clamps and check again
Did you check the spark advance with a timing light?
Check on startup thst all headpipes are heating up...if you can touch once longer than a a wee bit it might not ve running on al fours or you could have a carb gutting in and out . check float bowl levels using clear tube method.

Thatll give you a little ammo-

thanks for the reply!  doesn't hang up at all when revved.  i'll check for leaks asap and yes i did put my timing light on it.  timing is perfect.

checking the headpipes is a good idea. 

I did notice when i took the carbs apart that all the float levels were around 22mm.  So i changed them all to 25 and got fuel pouring out the overflow tubes on 3 of the carbs.  took them off and put them back where they were and only a drop or two from carb 2 now.  i'll search for "clear tube method" to get the details.   haven't heard of that one (but then i've only been at this for 4 months). 

jgger:   Daiichi points, NGK plugs and caps.  I got all my stuff from 4into1 and have been extremely happy with their quick service. 

thank you both for helping me out!  I'll do some more work and report back soon.     byron

[evinrude7]

What brand points and condensers did you get?

this^^^   find some TEC points and condensers.

[Gurp]

What brand points and condensers did you get?

this^^^   find some TEC points and condensers.

Always go with TEC so many of us have learned the hard way

[Bankerdanny]

The only dumb thing is not asking for help when you need it. All of us were new to this at some time and even the experienced members still run into a wall sometimes and have to reach out for help.

What does 'rebuilt carbs' mean to you? What did you replace and if you replaced any of the jets, needles, or float seats did you use OEM Honda/Keihin bits?

[cb550gwdsc]

  What does 'rebuilt carbs' mean to you? What did you replace and if you replaced any of the jets, needles, or float seats did you use OEM Honda/Keihin bits?

The kit i got from 4into1 included:

Shaped Float bowl gasket
Top Cover Gasket
Float Needle Valve & Seat
D274 Needle & Clip
Air Adjustment Screw & Spring
Main Jet #98
Slow Jet #38
Emulsifier Tube
o-rings

I did not replace the D274 needles and clips; i just didn't want to get into all that and they looked fine to my uneducated eye.  Don't know if the kits are oem....

Bike fired right up today but ran terribly.  Very rough and constant backfire.  I did check the header pipes today and found that 2 and 3 were cool enough to hold my hand on while 1 and 4 were too hot to touch.  So i took the carbs off (third time), disassembled 2 and 3, cleaned with brake cleaner and compressed air and that's where i stand now.  I'll get everything back together tomorrow and let you guys know what is happening.  thanks for all the views and comments!  byron

[Gurp]

Check the fire on 2 and 3. Sounds like you need to adjust one of your points.

[TwoTired]

Swap your condesers and see if the fire issue moves to 1-4.  If so change the 1-4 condenser.

You still have the stock muffler and air filter?

Cheers,

[AwesomeCB]

I've only got two cents to offer... You wrote you synced the carbs. Bench sync or did you balance using a manometer? If only bench sync, then you know what's next.

[cb550gwdsc]

Check the fire on 2 and 3. Sounds like you need to adjust one of your points.

Thanks for that.  I have to say that i woke up this morning and the first thing to pop into my mind was "2 and 3; what do they have in common?  same points and condenser!"  So maybe i didn't need to take the carbs apart 3 times.  Maybe I should have checked my new points and condensers again.  I'll do that this afternoon and report back. 

This 4 carb world is so different for me.  I've spent several years restoring air-cooled vw's so points, condensers, distributors, and carbs are not new.  but 4 at one time?  sheesh.  byron

[cb550gwdsc]

I've only got two cents to offer... You wrote you synced the carbs. Bench sync or did you balance using a manometer? If only bench sync, then you know what's next.

I used the mityvac from horrible freight to sync.  I'd love to have something with 4 gauges but i don't want to invest in that since i hope i won't be doing this many more times.  It worked great except for having to stop everything and connect to the next cylinder and go again.  I made sure I was at the same rpm for each reading.  did i miss something?  thanks  byron

[calj737]

I used the mityvac from horrible freight to sync.  I'd love to have something with 4 gauges but i don't want to invest in that since i hope i won't be doing this many more times.  It worked great except for having to stop everything and connect to the next cylinder and go again.  I made sure I was at the same rpm for each reading.  did i miss something?  thanks  byron

Not exactly perfect, but you will be very close. Certainly close enough to enjoy your bike.

[78whiteorbs]

  What does 'rebuilt carbs' mean to you? What did you replace and if you replaced any of the jets, needles, or float seats did you use OEM Honda/Keihin bits?

The kit i got from 4into1 included:

Shaped Float bowl gasket
Top Cover Gasket
Float Needle Valve & Seat
D274 Needle & Clip
Air Adjustment Screw & Spring
Main Jet #98
Slow Jet #38
Emulsifier Tube
o-rings

I did not replace the D274 needles and clips; i just didn't want to get into all that and they looked fine to my uneducated eye.  Don't know if the kits are oem....

Bike fired right up today but ran terribly.  Very rough and constant backfire.  I did check the header pipes today and found that 2 and 3 were cool enough to hold my hand on while 1 and 4 were too hot to touch.  So i took the carbs off (third time), disassembled 2 and 3, cleaned with brake cleaner and compressed air and that's where i stand now.  I'll get everything back together tomorrow and let you guys know what is happening.  thanks for all the views and comments!  byron

Kick it over check spark on two and 3 to rule out fuel.
1 coil fires 2-3 and one fires 1-4 (wasted spark)  clean your contacts and coil wires and ground right there at the coils.
Also if you swap coils and get fire on 2-3 and not 1-4 bingo... Could be points to as mentions but I like methodically trouble shoot in order of electrical flow when possible. ...u are close ...share ur victory when u succeed!!

[cb550gwdsc]

So i replaced the new 2,3 condenser with the old one that came with the bike (my hoarding tendencies pay off occasionally) and, voila!  runs like a champ (well, it runs much better).  also the 2,3 points were a little grey so cleaned that up.  seems it was the condenser all along.  at least i understand my carbs better now after fiddling with them for the past month.  yes i've been screwing around with this issue for a while and was ashamed to ask for help.  thanks for all your ideas.   

i think it still could be a little better.  what do you think?  (sorry for the poor video quality--old phone)

byron

[78whiteorbs]

Sweet victory!

Thanks for the follow up. May help the next guy...
Id recommend the 3k mile tune up if you havent yet as well as a mandatory carb sync afterwards for smoothest response and performance.
Well done!

[cb550gwdsc]

here is a beauty shot.  thanks again to everyone.  byron

[Bankerdanny]

Nice. I love a 550F with the original header. I loved the sound of the Kerker on mine, but that sweeping stock header just looks so cool.

[Motorcycle jones]

You forgot the most important part of all. The float needle! If they are not perfect it will never run right.
There are rubber tipped needles and all metal ones.

If you look at the all metal float tip you will see a shiny ring. that is actually a step worn into the needle. Replace it.

If it is a rubber tip needle the rubber pointed tip can be out of round and distorted. Replace it.

And rest the float height BY THE BOOK.

[cb550gwdsc]

I'm back.    Not running well again.  It really only ran well for about an hour.  So i decided to check the timing again.  Just started from the beginning.  disconnected the points and set them with my ohmmeter; adjusted to get the F mark aligned.  starts up and idles ok but 1,4 will not advance using my timing light.  2,3 advances to the correct mark with no problem.  reset the points gap over and over.  advance mechanism is clean and works great.  i mean, if it advances 2,3 then it must be ok for 1,4 also right? 

then decided to check the boots that connect the carbs to the engine.  sprayed wd-40 and you guessed it,  now i've got genuine honda boots ordered.  $10 bucks each.  ouch.  but i knew this hobby would not be cheap when i got into it! 

so my question is are these two issues connected?  and if so, why?  if not, what's next?

and on another front.  took the carbs off to wait on my new boots to arrive and noticed this:



probably just a tiny sliver left.  and the one on the other pair is slightly bent also so i'll just get new ones.
my haynes book lists it as part of "carb connector set B"  how do i order a part i cant put a name to?  so please someone tell me what to order (and who do you guys like to order from?  i only know about 4into1.)  thanks for looking in and commenting.  byron

[Bankerdanny]

There is somebody here on the forum that sells them, I will try and track it down