Author Topic: Carb problem 550  (Read 1646 times)

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Offline uksparky

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Carb problem 550
« on: March 30, 2017, 05:08:19 PM »
New battery came today, had ongoing thing with the wiring of the ignition, but got it sorted, good compression and spark to the plugs, plug wires on right cylinders, drained the carbs..fresh gas in tank....bikes been sitting almost two years....would not start......only under full choke it would run....  not getting over 1,500 rpm, sounded like a one cylinder lol. Only one of the headers was hot others warm, the carbs look like they were rebuilt some time ago. I drained the bowls and filled them using carb cleaner, let it soak overnight, but pulling the bowls in next..
« Last Edit: April 02, 2017, 09:18:08 AM by uksparky »
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Offline DaveBarbier

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Carb problem 550
« Reply #1 on: March 30, 2017, 05:48:47 PM »
I'd bet the carbs have to come off and be cleaned thoroughly. Pilot and mains jets are likely clogged.

Remove all jets and emulsion tubes and spray carb cleaner throughout. Make sure the tiny holes in the jets and emulsion tubes are all clear.

Those are PD carbs and have the pilot jets pressed in. Use pliers (parallel jaw pliers are nice for this) and twist and pull. Don't rock them in their seat. To install, just tap them back in with something soft like plastic or wood.

Offline uksparky

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Re: Carb problem 550
« Reply #2 on: March 30, 2017, 06:28:43 PM »
I could not wait, i pulled the bowls main jets plugged up, the crap gas in the bowls rotted the bowl seals....Where can i get the bowl seals..thanks
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Offline DaveBarbier

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Re: Carb problem 550
« Reply #3 on: March 30, 2017, 06:38:38 PM »
Here's one: http://4into1.com/genuine-honda-carburetor-gasket-set-16010-393-305-cb550k-cb750a/

I would replace the o-rings too because they're probably in the same shape as the bowl gaskets. No need to separate the carbs from each other. But remove the carb rack from the bike to clean them more thoroughly. May need a soak or even some time in an ultra sonic cleaner.

Offline uksparky

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Re: Carb problem 550
« Reply #4 on: March 31, 2017, 04:41:45 PM »
Thanks Dave parts on order decided  not to pull the carbs, got the main jets cleaned, junk gas in there ruined the needle seats, bowl seals, bowl drain O rings ok...Question on the pilot jets, got them out, cleaned them, i can blow air through them but small wire will not go all the way through the jet...is that normal
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Offline evinrude7

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Re: Carb problem 550
« Reply #5 on: March 31, 2017, 06:13:56 PM »
uksparky, i'm no pro here just a newbie and i don't know the 550 carbs.  i have a 750 that sat for 2 years and my biggest problem after getting the carbs, jets, etc cleaned was not setting float height.  once i really took my time and did that it changed everything.   
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Offline calj737

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Re: Carb problem 550
« Reply #6 on: April 01, 2017, 05:20:43 AM »
...i can blow air through them but small wire will not go all the way through the jet...is that normal
No, as long as the wire is small enough in diameter to pass through. The emulsion tubes really need removal and cleaning lest you be tormented endlessly by a stumbling idle.  :(
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Offline DaveBarbier

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Re: Carb problem 550
« Reply #7 on: April 01, 2017, 06:01:29 AM »
Yeah, without carb removal you're doing half a job. Your decision not to remove them was based on what?

Do the jets have a "K" stamped on them?

Offline uksparky

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Re: Carb problem 550
« Reply #8 on: April 01, 2017, 07:02:56 AM »
Yes today  i did get a small auto wire through the #42 pilot jets  main jets #90   no K...My decision not to pull the carbs is that they were rebuilt two years ago and that gas just left in the float bowls...i will spray the crap up into the emulsion tubes with carb cleaner..........thing is i bought this Honda not running 11,000 miles, been sitting two years, at least i would like to get it running on four cylinders, and see how it rides..if i get carb problem i will have to pull em of.....i know i am cutting corners and it might bite me in the arse....thanks
« Last Edit: April 01, 2017, 07:18:18 AM by uksparky »
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Offline Smudgemo

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Re: Carb problem 550
« Reply #9 on: April 01, 2017, 07:36:45 AM »
I'm no expert either, but I just did a full rebuild of my F carbs a few months back and no way would I have been able to get everything cleaned up w/o removing them.  Luckily, even though they hadn't been used in forever, the old gas didn't really cause much corrosion and the brass bits were still Keihin.  Then they sat for a couple of months off the bike after being used with current blended fuel.  I drained the bowls prior to sitting, and decided last night to have a look before reinstalling them.  They were noticeably affected.  Current fuel blends really are bad. I really think you need to remove them to get in there properly, and suggest you use soft wire like copper strands or nylon for opening the jets (if you aren't already.) 

For gaskets, I bought the shaped version from 4-1, but two of them expanded when I dropped the bowls and I wasn't able to reuse them.  Luckily I had the Honda non-shaped version on hand and got things back together.  Your K bike looks like it has more room to work, but when I reinstalled, I found it worked well to install the intakes, then the carbs, then the boots from the air plenum to the carbs (although I admit those pieces were new and very soft.)
-Ryan

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Offline DaveBarbier

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Re: Carb problem 550
« Reply #10 on: April 01, 2017, 07:12:02 PM »
Yes today  i did get a small auto wire through the #42 pilot jets  main jets #90   no K...My decision not to pull the carbs is that they were rebuilt two years ago and that gas just left in the float bowls...i will spray the crap up into the emulsion tubes with carb cleaner..........thing is i bought this Honda not running 11,000 miles, been sitting two years, at least i would like to get it running on four cylinders, and see how it rides..if i get carb problem i will have to pull em of.....i know i am cutting corners and it might bite me in the arse....thanks

Most people that clean carbs this way, from what I've read on this forum, tend to clean them a handful of times and finally do it the right way.

You have no idea what happened to the bike and how it was running previous to it sitting.

One more time, the right way to clean the carbs is to remove all jets, mixture screws, emulsions tubes and clean them individually and have the carbs on the bench to spray carb cleaner through all holes.

Lastly, you have aftermarket jets because they don't have a K stamp. This isn't ideal as they aren't made as well as the factory jets. They can be made to work but it may take some fiddling. Good luck

Offline uksparky

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Re: Carb problem 550
« Reply #11 on: April 02, 2017, 08:43:30 AM »
Thanks for that info Dave...job on hold at the moment. I bought the 550 knowing that the guy i was getting the bike from did not have his name on the title... ...DMV could not do transaction....the guy i bought the bike off had the 550 two years.. the title it was signed off with no date....so the guy who has his name on title sold the 550 to someone else...So DMV want a bill of sale from the middle guy ..to the guy i bought the 550 from....The seller did not tell me about the middle guy, and i did not ask....lesson learned...i contacted the guy i bought bike off and he will look for bill of sale. if that fails??
When the dust settles i will continue with the carbs....so Dave would you recommend me getting the K jets, wonder why they were changed...just checked new Honda jets not available parts from 4 into1 have aftermarket jets so i will leave it the way it is..
« Last Edit: April 02, 2017, 09:11:10 AM by uksparky »
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Offline DaveBarbier

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Carb problem 550
« Reply #12 on: April 02, 2017, 09:26:53 AM »
Oh damn, good luck with the DMV stuff. Sometimes that's the hardest part with these old things. Luckily here in CT they don't require a title on anything older than 20 years. CT also has an ownership affidavit that we can use instead of a title just to help assure the state that it's in fact your property now. Maybe CA has something similar?

When rebuilding carbs many people get aftermarket kits. Those come with brass parts most of the time and people just replace them not realizing that the jets are worse quality and 99% of the time the old stuff is just a little dirty and will last another 40 years if it's just cleaned up. Unfortunately they just throw them away thinking newer is better.

If money isn't an issue OEM is best, but I like to spend my money on bourbon instead so I'd say only replace them if you can't get it running right after everything is cleaned and the 3k mile service is performed. I mean, if it runs right and your plugs are all a nice tan color, who cares who makes the jets?

Hope this helps

Offline calj737

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Re: Carb problem 550
« Reply #13 on: April 03, 2017, 05:00:45 AM »
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline uksparky

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Re: Carb problem 550
« Reply #14 on: April 05, 2017, 03:45:58 PM »
Well i got the engine running after cleaning jets, new needle valves, bowl gasket, set float height....runs ok in garage... low idle bit rattle inside the engine, my last 550 sounded the same....set mixture screws 1.5 turn out 1400 rpm
Present bike 1982 900C Custom