Topic: guys please help, bought first cb 550 four

[andy8190]

so i just bought my first bike 1974 cb550 four. i didnt get a chance to ride the thing before i bought it but was show videos of it idling fine, and even saw the guy ride it in person and saw it idle. well i got it home today and started it up fine, road it around the block 3 times and it died. started back up but wouldnt say on, finally got it to stay on but had to give it lots of gas bc it wouldnt idle. now it wont start at all. what could this be? the kick starter worked fine earlier but now it has no resistance. could it be a timing issue bc i bought it at an elevation of 6500 and i am at 3000? please tell me i didnt get the shaft on this bike.

[mystic_1]

Well, doesn't sound too bad so far.  Elevation changes won't effect timing (ignition) but will affect carburation.  Your idling problems sound like carburation too.  Have you looked in the gas tank to make sure the gas is clean?  Sounds like you may have sucked a bit of dirt into your carb jets, which would account for the it-used-to-idle-ok-but-after-driving-it-a-bit-it-won't-idle-well-anymore symptom.

What's your mechanical skill level?  Sounds like a carb cleaning is in your near future, that's rather often par for the course on any used bike you'll buy.  I'd also drain the gas and replace it with fresh, if possible, you don't really know how old or clean the gas currently is.  Gas goes bad after some months, the gas in there could be years old for all you know.

What's the condition of the bike, otherwise?  Is the engine stock or has it been modified?  How are the tires?  Battery good?  Make sure the charging system is working.  Check for intake leaks?  Changed the air filter and oil?

Got pics?  We love pics here. 

Oh, and welcome to the madness!

mystic_1

[fuzzybutt]

check to be sure your gas cap vent is working. my 750k did the same exact thing when the tank vent got plugged, just fire it up and run it till it dies, then pop open the gas cap and see if it runs better again.

[andy8190]

so i should try and start it without the gas cap on?

i will go take some pics and come back and answer the rest of the questions best i can

[andy8190]

this is first pic. more coming

[andy8190]

what else would you like pics of?

[Really?]

Maybe ping the guy you got the bike from and see if he is familiar with the issue.  Maybe he has the answer.

I wonder if your battery has no juice left in it.  Maybe it is not charging or the battery finally just gave out.

Shell 93 octane and Seafoam can do wonders for dirty carbs.  I used have to clean the carbs every 6 months on my XVZ12DN until I started using Shell gas and Seafoam.  Been two years now and no need of cleaning.  Idles great.

[andy8190]

i did call the guy and he doesnt know what it could be, but if it were the battery the electric start wouldnt be firing would it, i sounds like it is firing ok just not actually starting. im not super mechanically inclined but i know what a dieing battery sounds like from experience. what about the kick starter issue, no one has addressed that, it has no resistance right now

[Really?]

Sorry, musta missed the part about it still cranking over.

[Really?]

Yea, I didn't.  I see nothing.  Oh well.

[andy8190]

well yeah the electric start still sounds strong but just wont get it started. maybe its not getting gas?

[andy8190]

What's your mechanical skill level? 
not mechanically experience unfortunantly
 I'd also drain the gas and replace it with fresh, if possible, you don't really know how old or clean the gas currently is.  Gas goes bad after some months, the gas in there could be years old for all you know.
the guy i bought it from said he rode it the other day and it did fine, put like 200 miles on it over a period of time.

What's the condition of the bike, otherwise?
the condition known is only what i was told, good working order
 Is the engine stock or has it been modified? 
assuming stock
How are the tires?
front tire looks a little weathered good tread, back looks good
Battery good?
battery seems fine
  Make sure the charging system is working. 
Check for intake leaks?  where were intakes be?
Changed the air filter and oil? have not done these yet

[andy8190]

could anyone answer this question, in the pic of the engine up close if you can see the 3 or 4 tubes below the choke lever, what are these? bc i noticed they dont go anywhere except to the bottom of the bike they don't connect to anything, they are just open


just looked and i think they are the carb overflow tubes, a little bit of gas came out of here earlier, is that significant?

[mcuozzo]

Andy,

I'm new to the world of Honda SOHC bikes as well so we are in the same boat.  Well actually you are in a better boat because I bought a basket case $100 bike to restore.  It is nowhere near running condition.  Carbs are off and are being cleaned\blasted.

Since I'm rebuilding everything on the bike (out of necessity), I can tell you that the tubes you are asking about are overflow tubes for the carbs, they should lead to nowhere!!!

So that's one thing you can check off the list...

[andy8190]

well thank you for that one, the thing that worries me the worst i think is that the kick starter gets no restistance sometimes. that cant be a good thing it seems. well i paid a pretty good sum for this bike so i am getting pretty frustrated. it looks great cosmetically though, i just want it to run as well as it looks

im prolly gonna bite the bullet tuesday and take it to the mechanic, i hate to though they rape you

[mystic_1]

This may be a stupid question, but do you realize that, in the pictures, your choke is on all the way?  Choke should only be needed for cold starting and initial warm-up, a few minutes.  Choke should be off otherwise.

mystic_1

[andy8190]

yeah i turned it on after trying to start it regular to see if mayyybbeee it would help.

but i could have left it on too long and flooded it, is that possible?

[mystic_1]

Another possible stupid observation:  Your fuel valve (petcock) appears to be in the OFF position.

mystic_1

[andy8190]

yeah i turn it off every time i turn the bike off

i might have left it on choke too long and flooded it, is that possible?

[05c50]

Andy, Welcome to the world of vintage motorcycles. You are right about those 4 tubes-overflows. The fact that gas came out of them may be significant. You may be on your way to figuring out your problems. For the most part, gas should not leak out, if it does, it may indicate a sticking float, or dirt/rust stuck in the needle valve. You are about to get very intimate with your carbs. Sounds like they may need a good cleaning. Lots of info on the site about that... just do a search. By the way, I have a 77 550F and those #@$% carbs are @#$% to get off the first time,but after about 4 or 5 times, it's not so bad. Keep us posted.
  Oh yeah, I almost forgot....don't hold in on the clufch lever when your using the kick starter

.............Paul

[andy8190]

thanks guys for all the recommendations and tips, please keep them coming, i took the carbs off of my 1975 bronco and cleaned those so if i have instructions i feel pretty comfortable. does anyone know a link to good ones? i will try that tomorrow before i take it into a shop. looks like im gonna be buying tools tomorrow haha

[andy8190]

05c50 thanks for the advice on the clutch

i dont have the problem of getting resistance on the kick starter anymore haha. im wondering if it is a fuel intake problem bc the need to keep it reved to run earlier today.

[mystic_1]

OK well first I'd do a basic check of a few things like spark (unscrew one plug, reconnect it to the wire, hold against engine and crank, should have spark), battery voltage (should be >12.5 with bike off), and wiring (none chafed, broken, corroded, or on fire) before you tear into the carbs.  If all seems well then cleaning the carbs is probably next.

Once you're committed to a carb cleaning (which I still consider likely to be needed), go HERE and scroll down to "CB500/550 Shop Manual" for an electronic copy of the manual.  Also grab the parts book for your bike, and the "Honda Common Service Manual".

Finally, download the Honda Carburetion Manual which is available in the Technical Library on the main website.

Once you've done your reading, mostly you'll need a phillips screwdriver, a flathead screwdriver, solvent, brushes, and lots of patience

Start by pulling off the carb rack, then flip it over and take off the float bowls.  You should be able to judge condition right away, parts should be clean and free of debris.  Unscrew and clean out the jets and float valves, then re-assemble and reinstall.  See where that gets you.

mystic_1

[andy8190]

like i said i might just bite the bullet and take it into the shop bc i am in grad school and am super busy these next 2 weeks. how much am i looking to spend for a tune up and a carb cleaning if needed?

i dont have anything to measure the volts of the battery

[mystic_1]

Hard to say, I've never had that done at a shop.  Call around and get some quotes, some places won't even work on bikes this old.  I'd guess at least 2 to 3 hours at the shop's labor rate, plus whatever for parts.  They'll likely want to replace the jets and float valves.

On the other hand you could probably do a basic cleaning in a couple of hours, hardest part is getting the carbs off and then on again.  No need to remove the carbs from the rack or take apart linkages, at this stage.  Just hose out the float bowl area and jets.

cheers,
mystic_1