Author Topic: Carb tips  (Read 3080 times)

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Offline Imjustanumber11

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Carb tips
« on: September 15, 2010, 03:24:35 PM »
Hi guys i have worked with carbs before but my new k3 is giving me a fist full of troubles and i was wondering if anyone has any tips or tricks on syncing and tuning.
The main issue im having is it idling at 3k. It has pod filters installed by the p.o. and a kirker 4 into 1 the bike hadn't been run in 6 years but i changed the oil and filter changed the spark plugs and threw in a new battery and it runs but has a very high idle. Ive adjusted the cables and have sprayed the boots with wd40 to make sure that the boots werent cracked and it did not change my idle speed. Help?
« Last Edit: September 15, 2010, 03:28:58 PM by Imjustanumber11 »
70' cb750 K0 The love of my life
14' triumph bonneville

Offline c(b)hris

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Re: Carb tips
« Reply #1 on: September 15, 2010, 03:36:29 PM »
this might be a dumb question but have you turned the idle adjustment screw?

« Last Edit: September 15, 2010, 03:48:17 PM by c(b)hris »
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Offline Imjustanumber11

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Re: Carb tips
« Reply #2 on: September 15, 2010, 04:05:16 PM »
Yeah unfortunately 3k is the lowest i can get it without it killing itself off
70' cb750 K0 The love of my life
14' triumph bonneville

Offline TwoTired

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Re: Carb tips
« Reply #3 on: September 15, 2010, 04:50:47 PM »
Clean the pilot circuits in the carbs.
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

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Offline Spanner 1

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Re: Carb tips
« Reply #4 on: September 15, 2010, 08:25:25 PM »
+1 on the slow jets being blocked..... @ 3,000rpm 'idle' the main jets are slightly open with the needles raised enough to allow the main jet into service, drop the slides/needles with the idle screw and there is no fuel available from the idle/slow circuit after the main is shut-off...... my 2c.
If your sure it's a carb problem; it's ignition,
If your sure it's an ignition problem; it's carbs....

Offline Legin

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Re: Carb tips
« Reply #5 on: September 15, 2010, 11:16:18 PM »
Make sure one of your carb slides isnt bottoming out at idle. When you press on the top tip of each carb pin you should feel a slight movement on each, if one doesnt move then its hard down and thats the problem. Carbs set this way ie by feel at closed throttle are normally very near on synch requiring only fine adjustment with vac gauges.

Offline Imjustanumber11

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Re: Carb tips
« Reply #6 on: September 17, 2010, 02:31:45 PM »
Im also having trouble starting after a little while could this be because the slow jet is clogged?
also whats the best way to clean out my slow jets? i Did check to see if the carbs were bottoming out and they arn't the have about a 1/4" give
70' cb750 K0 The love of my life
14' triumph bonneville

Offline flybox1

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Re: Carb tips
« Reply #7 on: September 17, 2010, 02:38:51 PM »
Im also having trouble starting after a little while could this be because the slow jet is clogged?

also whats the best way to clean out my slow jets?

Yes.

carb cleaner, simple green, and a small bit of copper wire to clear the hole.

and do a bench sync while they are off just for good measure.  ;)
« Last Edit: September 17, 2010, 02:40:55 PM by flybox1 »
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

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Offline Johnie

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Re: Carb tips
« Reply #8 on: September 17, 2010, 02:39:12 PM »
As long as you are cleaning the slow jet you may as well do the imulsifier tube and that jet too. Then re-sync so you can lower those slides.
« Last Edit: September 17, 2010, 02:45:20 PM by Johnie »
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Imjustanumber11

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Re: Carb tips
« Reply #9 on: September 17, 2010, 03:40:18 PM »
Thanks guys im soaking my slow jets and emulsifier tubes as we speak. My 2 and 3 slow jets were clocked sooo bad i couldn't get a needle through it.I don't know what'd i do without the wealth of knowledge on this forum, not ride my bike that's for sure.
70' cb750 K0 The love of my life
14' triumph bonneville

bollingball

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Re: Carb tips
« Reply #10 on: September 17, 2010, 04:05:57 PM »
After 6 years you have to go through the carbs no ifs & or butts about it.

Offline Imjustanumber11

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Re: Carb tips
« Reply #11 on: September 17, 2010, 05:21:01 PM »
the bike was actually dry stored when the p.o. finally parked it. and the floats were clean and dry when i checked it out. I got the slow jets and the emulsifier tubes cleaned up although the emulsifier tubes were pretty darn clean as is. but i still cant get the darn thing to idle and now its just hopping all around the board from 2k-4k and then it will die. As soon as i take the choke off it gasps for air and shuts down on me. Anyone in denver want a case of expensive beer and some money in their pocket? im frustrated!
70' cb750 K0 The love of my life
14' triumph bonneville

Offline Imjustanumber11

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Re: Carb tips
« Reply #12 on: September 17, 2010, 07:37:39 PM »
Hey guys i tooled around with the carbs a bit more and changed out the spark plugs and bam she fired right up with no choke on! I just wanted to re iterate the thanks and how i would be nowhere with out the wealth of knowledge on this forum! Thanks again guys! Im a happy camper now! Now for a photo of her as i know you guys love em. Her name is candy named by the original owner after an iggy pop song.
70' cb750 K0 The love of my life
14' triumph bonneville

Offline Johnie

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Re: Carb tips
« Reply #13 on: September 18, 2010, 06:19:16 AM »
Good to hear. And did you get the idle back where it belongs. Nice looking bike there.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Imjustanumber11

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Re: Carb tips
« Reply #14 on: September 18, 2010, 11:26:45 AM »
Yes yes i got the idle right to wear it belongs just below 1k and its running real smooth all the way up to 60. Now time for some cosmetics and then to get it insured and plated it shouldnt take me too long as its a pretty clean k3 as is and its only going to be my commuter bike so i can dig into my k0 this winter.
70' cb750 K0 The love of my life
14' triumph bonneville