There, we fixed it (kinda)

Lanse

Well-known Member
Hey guys!!

Hope everyone's having a good weekend... A little while back, I posted that my Shadow was having some running issues, and I called a buddy of mine who is good with engines and told him what it was doing, and he said it was a probably a carburetor problem. Wouldn't surprise me, I have a deep hatred of the things...

So, lastnight he stopped out and we took the bike apart and then we (mostly he) disassembled them and we cleaned them out with boiling water. It was the first I'd heard of the boiling water trick, and sure enough, it pulled out a large amount of crud and then we used some aresol carb & choke cleaner on the rest of it. Put it back together, got it running, and then sea-foamed it. She sounds a LOT better, except the problem Im having now is:

1) It cuts out under load unless the choke is on
2) It cuts out under load unless you leave the tank open.

This is another problem I've had off and on since I bought the bike, it'll be running fine, then it acts like its going to die, but you can pull in the clutch and it'll stay running and recover. I'd attribute this happening without the choke on to the fact that we dumped an almost full can of sea-foam into two gallons of gas (lol) and there's some marvel mystery oil in there too, but I don't like how it cuts out with the choke on. It doesn't happen nearly as often or as badly, but it still happens. I think the tank vents are clogged on this thing, although I don't know where they'd be or how to fix them...

Its ALWAYS something, but to its credit, when its running, it runs MUCH better even with the sea foam. Im glad we took it apart, we found one of the boots inside the carb had not seated itself right, and also one of the intake boots was off...

Any advice? The video tells more and goes over the cleaning itself a little better than I can type out. Hope you guys enjoy it!! :)
video1
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Another way to clean those carbs, use Pine-Sol cleaner. Do not dilute. Soak the carbs overnite, then use the hot water. Use a E-string from a guitar, run that small wire through the jets and openings to insure they are open. Then you may use the spray type carb cleaner and compressed air. This is the way I was told to clean carbs on my Honda 750custom..It works..
 
I don"t know the specifics of your carb but requireing the choke to help under load usually indicates a lean mixture.
Make sure it is really clean.Carb cleaner may help you really get a cleaner carb. Put a small wire through the passsages and blow them out with compresed air making sure they are clear. Make sure your main jet is clear and adjusted properly. Look at the needle and make sure it is not damaged. Make sure the float level is correct and you have unrestricted fuel flow to the carb.

Alort of problems arw erroneously ascribed to the carb when the ignition system is not performing properly. Make sure you have a FAT, BLUISH-WHITE SPARK, the color of lightning. Make sure the advance is working correctly and the ignition is properly timed.
 
Never heard of it huh? Most of us were blessed with two ears and one mouth. Not hearing is mostly caused by not using them in that proportion. :)^D

Posted this numerous times on several boards.

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(quoted from post at 15:21:53 11/11/12)

1) It cuts out under load unless the choke is on

Thats a sign its lean. Give the gas in the tank (that has Seafoam in it) time to work. It will start cleaning itself if its a gunked up gas issue. I think you said earlier the previous owner had screwed up the jets by drilling them, if thats the case, you may have put in to small of jets. Double check the needle height, some bikes it is adjustable. For a lean high speed issue, you would RAISE the needle, in other words, LOWER the clip.

Since you found the rubber boots not on the carbs correctaly, that is a suspected air leak spot and could be causing the lean problems. You may need to replace them because if they were put on folded or funky, they might not ever go back to shape. Test like other engines by using a propane torch to look for leaks or using grease to do a temp air seal.


(quoted from post at 15:21:53 11/11/12)

2) It cuts out under load unless you leave the tank open.

You said it, tank vent. Usually in the gas cap. Rust or bugs plugged it up. A plugged vent could be your lean issue as well as the other problems I listed. Its an easy test too, open the gas cap and do it redneck style, put a yellow chore glove in the tank to keep the gas from slopping out and take a ride. Smile at the people laughing at you....
 
The tank vent is probably built into the cap. I know that Honda ATV's of that vintage cap's were about 2 inches tall and had a valve to open and close the vent. They were known to go bad, had a 125 3-wheeler that would pull a vacuum on the tank, would start trying to die, crack it open and off it went again.
 
I boil them in water with detergent before I disassemble and then after soaking all parts in carburetor cleaner I boil again before rinsing and cleaning the ports/chambers/passages.

Any brand of detergent cleaner used liberally will work to soften the gunk and loosen the jets or plugs.
 
loosen cap,check for rust in tank,make sure no air leaks on multi carb setup,sync carbs on multi carb setup. old four carb setups were really fun to sync,especialy if the fuel flow was low.looks like you have two instead of four? also,remember you cant set carbs if ignition is not good.i believe jc whitney still sells a carb sync setup for multi carbed bikes.
 

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