Author Topic: CB550F blow by Parts and questions!  (Read 1115 times)

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Offline jmcalalang

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CB550F blow by Parts and questions!
« on: June 19, 2011, 11:42:33 AM »
Hey Everyone,

I recently bought a CB550F (75) and I am trying solve a motor dying questions, Do any of you know where i can get 18-21, 10 and 5? Would honda direct perhaps still carry these? or is there some fabrication i could make?

I bought a stock airbox this week in reverting back from the PO's terrible design at using a universal kn filter, and im missing these parts, i have the blow by tube hooked up to the bottom of the assembly but without the 18-21 parts the filter doesnt sit every well in there, nor would the gas/oil be filtered back up into the air-filter for re combustion.

The PO basically had a bracket coming off the aircleaner chamber which he fed the blow by and the air filter, i could be wrong but i thought sucking oil/gas back through the carbs would be creating quite a few of my problems, also wouldnt work very well :). I run VERY rich, and with a wide open throttle the bike will die. Gas mileage is garbage and power seems to be lacking. Ive pulled off the float bowls to look at everything its clean (very clean) and it doesnt appear that he changed the jets when we screwed with everything. So i thought reverting back to stock (like so many wise people have said) would be the best idea.

Cheers,

Jon

Offline bsobolik

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Re: CB550F blow by Parts and questions!
« Reply #1 on: June 19, 2011, 12:17:14 PM »
My bike is missing 10 and 5. In place of 5, someone shoved a hose clamp, which seems to be doing the job.

Offline TwoTired

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Re: CB550F blow by Parts and questions!
« Reply #2 on: June 19, 2011, 12:26:29 PM »
I fully support restoring the air box components (along with a new air filter.  I use the UNI NU-4055 foam/ reusable type).  Used air box bits from the bone yard or bike "customizers" will probably be the best parts supply outlets.  If Honda has them (probably), they will be expensive.

However, the breather system seems unlikely the cause of your engine run problems.

The assumption is always that the bike ran well off the show room floor.
So, if it is returned to that condition, it will run well enough to sell thousands of them. (History proved that!)
The resurection path should begin with the routine 3000 mile tune up check list.  Most certainly, this should be done before "fine tuning" carbs.
Point gap, point timing, spark plugs - clean and properly gaped, tappets adjusted cold, and a compression check wouldn't hurt while "bringing back" a motorcycle.

If all the above are in a "known" state, then the carbs are addressed.
"Clean" means different things to different people.
So, "very rich", could mean that the mains emulsion tube wasn't removed and cleaned during the cleaning process.
Or,... that a main jet oring is corrupted, or that the main jet retention springs are missing, or that the slide needles are set too high, or that the slide needle jet is damaged.
...Or that the float valves are not stopping fuel flow, or that the floats are set incorrectly.

 If you have it running, check the head pipe temps can lead you to a dead cylinder.  Since the carbs use different fuel paths depending on throttle position, you can use this info combined with a cooler head pipe to refine where scrutiny is warranted.

For example, a cold head pipe at idle points to a carb with pilot circuit issues.

These are some ideas for you to investigate.  The more solid data you can provide us, the more directed a response can be made toward a solution.

Cheers,

Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline dave500

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Re: CB550F blow by Parts and questions!
« Reply #3 on: June 19, 2011, 12:38:11 PM »
have a look at the numbers stamped on your slow and main jet,and the position of the jet needle,you said it dosent appear the jets were changed,when pods are fitted people change jets a lot.

Offline jmcalalang

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Re: CB550F blow by Parts and questions!
« Reply #4 on: June 19, 2011, 01:46:07 PM »
So all the header pipes are hot, definitely atleast firing on all, i dont have an IR temp gauge but spraying water burns off on each one, i know the plugs are good cause i also changed all those. i can pull the bowls again and look at the jets this week, hate ripping it all apart though  :(. Idle likes a champ ive set it right in range 950-1050 and it will idle on its own for as long as i let it (last time was 30 mins) followed it up by a 20 minute ride, i went full throttle on the 20 minute ride and it died, though it started right back up and i drove home.

Cost isnt so much a factor, if honda has the parts i would order them, new airfilter was 35$ i would assume the bypass filter on the bottom would be about the same, if the make one...

Does anyone have a link for the 3k tuneup, i could do that just cause im sure it hasnt been done in a very long time.