Author Topic: '78 550k - yet another question  (Read 5046 times)

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Offline egar

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Re: '78 550k - carb cleaning
« Reply #25 on: July 31, 2005, 07:30:02 PM »
TwoTired,
 Thanks yet again. Would you advise totally dismantling the carbs from each other for the next cleaning? I printed out the pages for this process from the Web site that had the link containing the manual. I keep getting this funny feeling my floats aren't perfect in measurement. It's amazing that the human mind could conceive of all these tubes and parts working in synch to fuel the engine. I must say this is a true education for someone who has never been much of a mechanic. But it is what I asked for when I sought a cheap bike to bring back from the dead.
sohc4

'04 ST1300, '70 cb750KO

Offline TwoTired

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Re: '78 550k - carb cleaning
« Reply #26 on: July 31, 2005, 11:57:33 PM »
TwoTired,
 Thanks yet again. Would you advise totally dismantling the carbs from each other for the next cleaning?

You're welcome. And, no, I don't think so.  I haven't encountered carbs that couldn't be cleaned while still assembled in the bank. But, then, I have not seen your carbs. It is significantly more work and requires a higher degree of finesse to dismantle, then reassemble and properly adjust all the linkages if you do.  I would certainly not attempt such with out first having gasket sets for all the carbs and the interlinking tubes.  The 77-78 cb550k carbs are more difficult to separate than earlier models.  The choke butterflies have peened screws on a shaft common to two carbs.  I don't see what advantage separating the carbs will buy you unless it is necessary the chemical dip them.

I keep getting this funny feeling my floats aren't perfect in measurement.

Why do you think this is?

It's amazing that the human mind could conceive of all these tubes and parts working in synch to fuel the engine.

Well, carburetors weren't conceived this way. They evolved. You know in the same way grass huts evolved into skyscrapers.  I can assure you there isn't anything there that isn't needed.  The systems are there in response to some requirement in engine performance.  Also, you only need to understand how one of the carbs work, as the other three are just copies.
Perhaps it will help if you imagine the carbs supply not just fuel, but a combustible mixture of atomized fuel and air. The carburetor meters both as well as controls the total volume supplied to the cylinders.

I admire your willingness to learn something new.  Rescuing neglected machines can be quite rewarding.  The payoff of having it move you through the breeze because you made it work again can be adictive, though.

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 bryanj

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Re: '78 550k - yet another question
« Reply #27 on: August 01, 2005, 01:08:22 AM »
Those pilot jets have "cross drilled" holes in the bit that you cant see and they block up.
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline egar

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Re: '78 550k - yet another question
« Reply #28 on: August 01, 2005, 04:42:26 AM »
Bryan J,
           The holes on the sides of the pilot jets were nice and clear when I put them back in last time. I could see sunlight through them. Thanks, though, they're easy to overlook. I didn't even see them the first time.
sohc4

'04 ST1300, '70 cb750KO

Offline egar

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Re: '78 550k - Celebration
« Reply #29 on: August 01, 2005, 03:24:19 PM »
You guys are the only group that would comprehend my elation. The bike fired up and stayed running for the first time since I bought it! I killed the engine and fired it right back up a few minutes later! What a feeling. My family thinks I'm nuts but I had to share the joy.
Thanks, TwoTired, for all your help! Needs some tuning but at least I can move onward to the next steps. Will keep you all up to date. What a badass sound this little bike makes! It was idling high so I backed off on the main idle screw, but now it sounds like the carbs need adjustment. I don't mind at all. I've already succeeded beyond my wildest expectations. I'll shut up now.....
sohc4

'04 ST1300, '70 cb750KO