Author Topic: Fuel jet clearing  (Read 2464 times)

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thegoochking

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Fuel jet clearing
« on: May 16, 2008, 11:07:17 AM »
Hey guys i was told that if i put carb cleaner in with my gas it will help clear out gunk from my fuel jets which i was told is probably the culperit to my idling problem. Will this actualy work? the bike hasnt been ridden in about 5 years till recently and probably longer from the owner before that one.

Offline mystic_1

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Re: Fuel jet clearing
« Reply #1 on: May 16, 2008, 11:17:52 AM »
With a bike that's been sitting that long, I'd say the jets should be pulled out and soaked in carb cleaner.  Adding carb cleaner to the gas is more of a preventative measure, in my opinion. 

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Offline Gordon

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Re: Fuel jet clearing
« Reply #2 on: May 16, 2008, 11:24:27 AM »
Fuel tank additives can help clear out jets and fuel passages that are only partially clogged because the cleaner can get through the holes.  Jets that are clogged from sitting are often completely blocked by gum and varnish because of the very small size of the holes (idle jets especially) and have to be manually cleaned.

thegoochking

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Re: Fuel jet clearing
« Reply #3 on: May 16, 2008, 11:33:22 AM »
any guides or advice on pulling the jets and cleaning them? ive never done engine work and brand spanking new. Dont want to go and make the bike worse by screwing something up

Offline TwoTired

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Re: Fuel jet clearing
« Reply #4 on: May 16, 2008, 11:33:43 AM »
I think those add-to-gas cleaners will only do "something" when there is still some fuel flow through the jets.  If the slow jets are currently plugged, there is no flow through them.  And, getting cleaner to them is going to be "iffy", as the blocked part sits higher than fuel level in the carbs.

Agitation would be the only hope, in such case, even if slim.  Running the bike with blocked slow jets will likely overheat the motor/blue exhaust pipes, and be no fun to drive about.

If you have lots of girl friends, you could borrow their massage vibrators and strap them to the carbs, buy batteries in bulk and let the bike buzz for a few days.  Take pictures and post them here!

Or, you could take out the slow jets and clean them.

Your call..

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.

thegoochking

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Re: Fuel jet clearing
« Reply #5 on: May 16, 2008, 11:41:42 AM »
HAHA that picture would make for a nice post. The bike runs i can actualy take it out. I just cant get it to idle at anything less then 3000 or just under the 3000 mark. Which is why i think theres a blockup somewhere. But im not mechanicaly inclined, How much damage can i do by pulling those jets and cleaning them.

Offline TwoTired

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Re: Fuel jet clearing
« Reply #6 on: May 16, 2008, 11:48:13 AM »
How much damage can i do by pulling those jets and cleaning them.

A lot, if the only tools you own are hammers and chisels!

Probably should give us some information about the bike in question.  Some carbs have easier to clean jets than others.

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.

thegoochking

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Re: Fuel jet clearing
« Reply #7 on: May 16, 2008, 11:49:03 AM »
the bike is a 1973 cb500f

crystalhelix

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Re: Fuel jet clearing
« Reply #8 on: May 16, 2008, 12:09:50 PM »
At a minumum pull the idle jet, and main jet and clean them out and look through them to make sure they are clean.  Also pull the emulsion tubes.  There are also tiny filters on the back side of the filler needle nut.  That's where I found most of my rust debris.  A bunch in the emulsion tubes as well.  And clean out the float bowls.

Offline TwoTired

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Re: Fuel jet clearing
« Reply #9 on: May 16, 2008, 01:35:07 PM »
Well ok, but the F models didn't happen till 75 in the US and all the Cb500 here are K models.  A 73 would be a K2.

Anyway, those carbs can be 75-80% cleaned with them on the bike, and certainly the slow jets.  But, it will take some dexterity and prowess to do it in the small space that is there.

Tough to recommend this to someone who professes to be "not mechanically inclined".

You have to remove the 4 screws holding the float bowls on the bottom of each carb, which allows access to the inner bits.  Proper length, correct fitting screwdrivers are a must. It is here I make an assessment of just how gunky they are inside.  If it's too bad I put the bowl back on and remove the carbs from the bike for a bench overhaul.
If it is just filmy and some thin deposits on the inards, then you locate the short post with a slot in it and unscrew that from the carb body (Important - note how much force it took to remove it).  Hold it up to the light and look through it.  There is a hole  inside that tube about 0.016 in. diameter. Aerosol carb cleaner will often clear the hole, and a bit of compressed air can help.  When you can see light through them again, you can put them back.  Don't use any more force to install than when you took it off, or you'll break it off, usually causing blue words to permeate the area.  1&4 carbs aren't too hard to access. 2&3 are more challenging.  Mirrors, patience, and ability to stand on ones own head, is a great asset.  But, the actual process is the same as the outer carbs.
Unless you plan on replacing all the Orings inside the carbs, leave your main jet in place as well as the main emulsion tube, (which usually require removing the slides to poke them out from the top.)  Especially since you report your bike running above 3000.  Do all the head pipes get hot?

With the insides back into position put the bowls back on and pray the bowl seals don't leak.  Check/clean your petcock sediment bowl/filter, and your gas tank for fuel contaminants, or your clean jets won't stay that way.

Or, pay someone $400 or more to clean your carbs. (Now, you know why I learned to do this myself.)

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 neil young

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Re: Fuel jet clearing
« Reply #10 on: May 16, 2008, 01:44:08 PM »
(Now, you know why I learned to do this myself.)
how true.......how true ;) not to mention the horror stories i have heard about paying big bucks and still having problems with the carbs.or what ever else was worked on.
my first bike (81 Yamaha Seca)was a money pit to me and a gold mine to my mechanic for about 3 months untill i couldnt take it any more and decided to get a manual and look at things myself.waaaayyyyy better off.after that the difficult part was finding the parts #'s and locating the stuff i needed.
« Last Edit: May 16, 2008, 01:50:22 PM by neil young »
1972 CB500 k1
1974 CB550
1977 cb 550
82 suzuki GS 750tz.......16  valves  baby
2008 Triumph Scrambler

thegoochking

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Re: Fuel jet clearing
« Reply #11 on: May 16, 2008, 02:07:48 PM »
Ok let me take that back im not mechanicaly not inclined i just have never worked on any type of engine before. Ive got tons of tools so i have any tool i would need. Im just not very comfortable with messing with the carborator. But i also am not going to pay a mechanic 400 bucks or more to clean the dam fuel jets for me.

thegoochking

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Re: Fuel jet clearing
« Reply #12 on: May 16, 2008, 02:09:17 PM »
it is a cb500 four says it on the side pannels. Maybe something is wrong haha the title says its a 73 but if the fours started after that then i dont know what the hell happened.

Offline neil young

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Re: Fuel jet clearing
« Reply #13 on: May 16, 2008, 02:22:17 PM »
side panels dont mean #$%* ;D
i have a 550 engine in a 500 frame ...with 500 side panels ;)
1972 CB500 k1
1974 CB550
1977 cb 550
82 suzuki GS 750tz.......16  valves  baby
2008 Triumph Scrambler

Offline eurban

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Re: Fuel jet clearing
« Reply #14 on: May 16, 2008, 02:23:39 PM »
The "F" doesn't stand for "Four" but rather denotes the sport models which typically have sportier styling / ergonomics and a 4-1 exhaust.

thegoochking

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Re: Fuel jet clearing
« Reply #15 on: May 16, 2008, 02:30:52 PM »
it says 500/four on the panel, has a black 4-1 exaust. How else can i tell what year it is

Offline TwoTired

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Re: Fuel jet clearing
« Reply #16 on: May 16, 2008, 02:41:13 PM »
The F models were introduced as the Supersport for the 75 model Cb550s.  These were made through 77. (F0, F1, F2)

The CB500 was introduced in 1971 and was produced through 1973.  These were denoted by Honda to be the K0, K1, and K2 respectively.
The line changed to the Cb550 in 74 and the K model was again offered, beginning with K0 through K3 for the 77-78 model.

The K and F designators are important when you wish to order parts for your machine.

As the story goes, "K" is a Japanese translation for a word meaning "revision".  I don't know what the "F" was derived from...

The frame serial number will translate to the year/model of production.
73 Cb500 production began with SN # CB500-2100001~

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 andy750

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Re: Fuel jet clearing
« Reply #17 on: May 16, 2008, 02:52:21 PM »
I don't know what the "F" was derived from...

F = Fast

The simplest solutions are the most obvious but often overlooked  ;) ;D

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thegoochking

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Re: Fuel jet clearing
« Reply #18 on: May 16, 2008, 04:28:57 PM »
Ok since i see i have tons of support at this awesome forum, i am trying to locate a slow oil leak i have. The previous owner said they were tighting the screws to put the oil pan back on and tightened to hard and heard a crack. Now the oil is leeking out from somewhere that seems to be arround the edges of where the can connects to the block and also seems to be coming from up arround where the chain is. I cant seem to pin point the leak. 1 does anyone have any imput on where this leak might be comming from and 2 does anyone know where i can get an oil pan for a 73 honda cb500?

Offline neil young

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Re: Fuel jet clearing
« Reply #19 on: May 16, 2008, 05:35:59 PM »
wash the bike and then spray some foot powder on the gasket areas of the engine.
 as for the oil pan .....ebay and scrap yards are your life now ....enjoy!
1972 CB500 k1
1974 CB550
1977 cb 550
82 suzuki GS 750tz.......16  valves  baby
2008 Triumph Scrambler

thegoochking

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Re: Fuel jet clearing
« Reply #20 on: May 16, 2008, 07:15:33 PM »
Here She is      

Offline mystic_1

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Re: Fuel jet clearing
« Reply #21 on: May 16, 2008, 09:12:14 PM »
Wow!

She looks nice.

mystic_1
"A ship in harbor is safe, but that is not what ships are built for."
- John Augustus Shedd

My build thread:  http://forums.sohc4.net/index.php?topic=68952.0

Offline neil young

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Re: Fuel jet clearing
« Reply #22 on: May 16, 2008, 09:57:37 PM »
snazzy 8)
1972 CB500 k1
1974 CB550
1977 cb 550
82 suzuki GS 750tz.......16  valves  baby
2008 Triumph Scrambler

thegoochking

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Re: Fuel jet clearing
« Reply #23 on: May 17, 2008, 06:18:28 AM »
Yea now i just need to get her running right  ;D