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View Full Version : 38's w/ clogged return?


WAB
04-10-2006, 07:30 PM
The return for the slave carb is clogged somehow. It was also acting like it was running out of fuel when I tried to go over idle. I tried to blow straight through the return fittings and cold only get air to come out through the hole that would be on the inside of the carb. Make sense?

I know it not because of way to small jetting, and it should not totally die when it tries to pull more fuel. Could this caused by the clogged return?
How do I clear it safely w/o enlarging the tiny return hole??

butti
04-10-2006, 07:39 PM
you didnt like the single?

WAB
04-11-2006, 01:58 PM
Just bored the 38's myself so I wanted to try them. they ran ok at first, then we took them off to rejet. Then it would not run at anything over idle.

Clogged returns....anybody???

Idok
04-11-2006, 02:15 PM
I need to get my carb back from this man IMMEDIATELY

Mile9c1
04-11-2006, 03:30 PM
Are you thinking that it's starving for fuel? It wouldn't be starving if the return were clogged, it'd be richer.

Big Kahuna
04-11-2006, 03:37 PM
Just bored the 38's myself so I wanted to try them. they ran ok at first, then we took them off to rejet. Then it would not run at anything over idle.

Clogged returns....anybody???


what do you mean you bored them yourself???

Idok
04-11-2006, 03:56 PM
what do you mean you bored them yourself???


you know what he means :bigeyes:

Mile9c1
04-11-2006, 04:22 PM
:bigeyes:


:haha:

Idok
04-11-2006, 04:24 PM
The return for the slave carb is clogged somehow. It was also acting like it was running out of fuel when I tried to go over idle. I tried to blow straight through the return fittings and cold only get air to come out through the hole that would be on the inside of the carb. Make sense?

I know it not because of way to small jetting, and it should not totally die when it tries to pull more fuel. Could this caused by the clogged return?
How do I clear it safely w/o enlarging the tiny return hole??


i used to ask my g/f the same question....:biggthumpup:

WAB
04-11-2006, 06:38 PM
Jeez, do we need a seperate section for f'ing off? somebody just try to help me out and cut the ****. :biggrin: :banghead: :biggrin: :banghead:

Yes, I bored/trued my own 38's; removed the large triangle shaped boss thing, the 3 lines on the inside and opened them up right above the butterflies. Took out a whole buncha alum.
I jetted to 140 highs and 80 lows & it ran ok, but had a slight hesitation at midlow-midrange. Adjusted the screws and only got worse. I was thinking I need to go smaller in the jetting, so I put in 135mains and 77.5pilots(I think) Put it back in the water and it was dying like running out of fuel when I tried to get over idle speed. Even if I am too small on the jets, it should rev for a sec and die back down or run poorly. I had to use the primer to get back in. Thought maybe I messed up something in doing the rejetting or the filters were clogged. It all looked ok but the clogged return for the slave carb. I did not know what a clogged return would make it act.

trued 38's
62t cyl w/ raised & widened exh ports
B pipe w/ long chamber
V-force II

?

#ZERO
04-11-2006, 07:10 PM
The front 38mm Mikuni Carburetor Return Plate has a 0.4mm restrictor built in it because there is only one fuel pump mounted on the back carb. Removing or modifying this hole will cause a fuel pressure drop in the front carb. I would check the pop-off pressure on your carbs or check to see if it has the dull silver 95 gram spring. You should not need more than 77.5 on your pilot jets; I would try 72.5 or 75 jet sizes. Do you have a picture of the top of your carburetors? I would like to see amount of grinding done.

WAB
04-12-2006, 08:25 AM
Ok, so it does not sound like the blocked return was causing the running out of fuel dying issue.
You should be able to cover the hole on the inside of the plate and blow air straight though the slave carb's return tubes though, right?
I did not take a pic of the tops of the carbs after boring. I did not really open up the tops, just cleaned out the throats.