Topic: All of a sudden....blaaaah!

[ironrod75]

A few questions...

1975 CB550
1) Identification chart says it is a K1. BUT K1 has is a 4-4 exhaust. I have a 4-2 with one pipe on each side. Is this unusual or perhaps a dealer modification?

2) Just FYI, this 550 sat covered in the garage since 1984. I got all the rust out of the tank, rebuilt the lower half of the carbs, new plugs and it fired on the first try. It ran but had some power issues which I figured was because I had not vacum synced the carbs yet. Drove it all summer like that. So last fall I drove to the store and all was as it was, went in for 15 minutes, came out and it just wouldn't stay running at idle and ran really rough when I could keep it running. Barely got it home and put it to bed for the winter. My #1 carb had been leaking from overflow, so yesterday I eyeballed the float adjustment to stop the overflow. (I know this is improper, but I wanted no leakage while I figured out the initial problem.) It's a very hard start but I can get it started and it will run at a low idle (800 rpm) after it's warm. But if I try to accelerate quickly, it just dies.

I cannot figure how one carb going fully out of whack would cause this sudden problem, so I figured maybe junk in the fuel line. I dumped the tank and there was a few eraser size very thin pieces of rust and some small particles, but the in tank filter was clear and flowing.
Could it be electrical?

Thanks for the help.

[Jimsun]

First question is your current exhaust are probably jardines 2-1 (lively sound).

Second question

Remove the carbs fully. Clean the bowls again and make sure that ALL THE PASSAGE WAYS ARE CLEAR. Reassemble. Then test ride

[Stev-o]

Hey...

1.  The previous owner could have changed the exhaust for any number of reasons.
2.  Sounds like you need to do a proper clean of the tank and carbs.

[ekpent]

Make sure its even running on all 4 cylinders by checking head pipe temps. Along with tank and carbs make sure the timing is good and the points are clean and the condensers are good if stock. What kind of air filter do you have, stock box or other ?

[ironrod75]

@ Jimsun...yes, 2-1. DOH!
@ Steve-O....Original owner was my dad, but he may have changed them. I didn't consider that.
@ ekpent....How do I check pipe temps? Bought an air box from Honda but it fit fer carp. Foam filter. I put the stock one back on, but I blew it out and it looked okay.

@ All....I was afraid that I'd have to clean the carbs again. I was advised against separating the carbs previously. Do I have to do so to clean them properly? Short of an interior coating of the tank I think I've done all I can to clean it. If the constant production of the very fine rust is getting past the in-tank filter, will an additional inline filter work? I considered installing a Dynatek DYNA S electronic ignition. Are they straight forward to tune or do I need a degree?

Thanks for the help.

Wes

[mystic_1]

How do I check pipe temps?

If you do not have a fancy non-contact thermometer, feel them with your hand as the bike is first warming up.  You'll be able to tell if some heat up more quickly than the others after just a minute or so.

If the pipes are already hot, fold up a wet rag and touch it very briefly to the pipes near the head.  You'll be able to tell from the sound of the sizzle.

Having acquired a number of small burns from hot pipes over the years, I now use a non-contact thermometer 



mystic_1

[lrutt]

Add an auxilary fuel filter after the petcock and reclean your tank. Then fully strip the carbs and do a thorough cleanup on them.

Once you've done that you can do a bench sync using a drill bit under the slides. Open the idle adjust until you can slide a 1/16" bit under the slide, then go down the line and adjust each carb so it has the same clearance under the slide for the bit. Almost like setting valves. You will be surprised at how close that will get you and will likely be adequate if you don't have a set of gauges. I've only had to very minimally tweak carb syncs after doing it that way.

Same for setting points if you don't have a timing light. Disconnect the condensors and use a VOM. I prefer the old analog VOM meters to the DVM digital meters for this. You can get timing spot on doing the static method this way. Rotate the motor until you see the F line up, the needle will just start to move as the points close.

Once you are done bench tuning, take it for a ride. You just might be amazed.

[ironrod60]

@ mystic_1....lol As I started reading your advice about touching the pipe, I thought "Love it! This guy is a wise-ass just like me!" Then read on. I'll try the hand test first.

@ All...Here is a picture of my 550.

[ironrod60]

@ Irutt...."Then fully strip the carbs..." = Just so I understand.....separate all the carbs?

1) How many turns on the initial air/fuel screw?
2) Idle speed rpm?

[flatlander]

do you have a service manual? if not then now's the time to download:
http://manuals.sohc4.net/cb550/

[Tews19]

@ mystic_1....lol As I started reading your advice about touching the pipe, I thought "Love it! This guy is a wise-ass just like me!" Then read on. I'll try the hand test first.

@ All...Here is a picture of my 550.

Wow I like the bike.

[ironrod60]

@ flatlander....I'll dwnld it. Gacias!

@ Tews19...Thanks!

[seanbarney41]

If you have not done the regular 3000 mile tune up as specified in the manual, you probably have several other problems in addition to dirty tank and carbs.  I would service your timing chain, valves, and points and timing first.  You need to get a manual.

[ironrod60]

I'll do the tune up.

Also, do I completely separate the carbs? I've had different views on the wisdom of this, mostly because putting tyhem back together is quite a job for a novice.

[evanphi]

I'll do the tune up.

Also, do I completely separate the carbs? I've had different views on the wisdom of this, mostly because putting tyhem back together is quite a job for a novice.

Not a big job. Just take your time, stay organized (one bin per carb), watch some YouTube vids beforehand... and TAKE PICTURES.

[Tews19]

Take completely apart and as Evan said bag each carb individually. Its very easy, you have to pay attention to detail and not lose any parts.

[ironrod60]

Well, I'll give it a go. What about a source for videos? I tried youtube, but all I get are total rebuilds, and mostly cafe racer conversions. Does sohc have a videos section?

[evanphi]

What model carbs do you have? The number should be stamped on the carb body.

[ironrod75]

Carbs are 022A

[bender01]

I wouldn't separate the carbs. Probably a piece of junk got into the emulsifier tubes or other jets. I don't like fuel filters but you may need one for awhile to  make sure all the junk got free in the tank.

[grcamna2]

I'd deal w/ the rust in the fuel tank right away.The 'vinegar treatment' works well but you need to let it sit full w/ straight vinegar for a good while to get all the rust out.Then flush it out completely w/ water and dry it out as soon as possible w/ a continuous blast of high volume compressed air or the hot exhaust from a shop vac. outlet so that it won't 'flash rust' on you; seanbarney41 gave me 'the formula' on how to do it right 

[ironrod60]

I can let it sit. How long is a good long while? Hours? Days?

[ironrod60]

Oh BTW, I adjusted the valves.
It's clear that I was running rich. I pulled the plugs and every one was black and wet. It doesn't smoke gray, so it isn't oil. Aside from that it smelled like fuel.

[grcamna2]

I can let it sit. How long is a good long while? Hours? Days?

2 full days(48 hrs) should take care of it.

[ironrod75]

Can I ask about a source for miscellaneous videos on bench syncing, etc.?