_chiefjt Posted January 2, 2013 Report Share Posted January 2, 2013 So my hitachi carb on my '86 720 flooded. It's just dumping gas down the intake and the glass to check the float level is full. It was good for awhile but now it's messing up again. I adjusted the float a little just so my mom can run to the gas station real quick but it wouldn't start when she shut it off. She had to pedal it to start it. And yesterday I went to start it cause the float level was below that dot and it flooded again. Any help to try and fix it. If not then I guess I have no choice but to buy a 32/36 weber. Trying to save for other stuff for my truck. Quote Link to comment
datsunaholic Posted January 2, 2013 Report Share Posted January 2, 2013 I'm getting mixed messages- you say the float level is "full" then "below the dot". When it's running, is the fuel level (not the float itself) visible in the window? If it's too high, and adjusting doesn't change anything, then either the float is sunk (has a hole in it causing it to sink, which means the float has to be replaced) or the float VALVE isn't sealing. That can be because the needle valve itself is bad, VERY badly adjusted, fell out, stuck, or the fuel return back to the tank is plugged (which causes the fuel pump to force fuel past the valve). The sunk float is usually the cause- modern fuel plays havoc on floats, so they develop pinholes, fill with fuel, and sink. Take the float out and shake it. Hear fuel in it? It's bad. Quote Link to comment
crackerjack69 Posted January 2, 2013 Report Share Posted January 2, 2013 I can send you a stock hitachi float if it turns out that's the problem, but my guess is they're pretty cheap new. Quote Link to comment
h190 Posted January 2, 2013 Report Share Posted January 2, 2013 a carb kit also comes with a new needle and seat. Its always good to replace them. If the problem persists then throw that junk as far over the hill as you can and order a weber. Quote Link to comment
datsunaholic Posted January 2, 2013 Report Share Posted January 2, 2013 Don't bother trying to get the float from Rockauto though- my Mom ordered one a couple months ago and got a Ford Tempo power steering hose. Called 'em and they had the same part number... all in stock were power steering hoses. Quote Link to comment
crackerjack69 Posted January 2, 2013 Report Share Posted January 2, 2013 Don't bother trying to get the float from Rockauto though- my Mom ordered one a couple months ago and got a Ford Tempo power steering hose. Called 'em and they had the same part number... all in stock were power steering hoses. Ha! That's screwed up. Quote Link to comment
ggzilla Posted January 2, 2013 Report Share Posted January 2, 2013 Same thing can happen to a Weber, but you can't see the fuel level as Weber has no sight glass. Quote Link to comment
racerx Posted January 2, 2013 Report Share Posted January 2, 2013 looks like this one for weber 32/36. Yep..happened to me before and could not adjust my carb and would flood. housing was cracked and luckily had another weber and installed the needle seat. Good Luck. Quote Link to comment
datsunaholic Posted January 2, 2013 Report Share Posted January 2, 2013 Ha! That's screwed up. At least she got her money back, and they didn't have her send it back. So if anyone needs a Ford Tempo power steering hose cheap... Quote Link to comment
_chiefjt Posted January 2, 2013 Author Report Share Posted January 2, 2013 Well I adjusted the float so that's why it was below the dot of the sight glass. I've already rebuilt the carb with carb dip cleaner and a rebuild kit. It did come with that new needle so I put that in. I rebuilt it about 3-4 months ago. I have the carb out but I'll test the float. How would I test the fuel return line? Quote Link to comment
datsunaholic Posted January 2, 2013 Report Share Posted January 2, 2013 Compressed air. Should hear air blowing into the gas tank. But do that with the cap off! Cap on, it'll pressurize the tank and blow fuel out the unconnected side of the return piping. Quote Link to comment
_chiefjt Posted January 2, 2013 Author Report Share Posted January 2, 2013 Okay figured. So I tested the float and it seems like its holding up. Put it in a sink full of water ad it stays afloat. I even held it under water for a few minutes and didn't hear any swishing in it so I think it's good. Now to test the fuel return line. How would the fuel return line get plugged? Quote Link to comment
datzenmike Posted January 2, 2013 Report Share Posted January 2, 2013 I have the carb out but I'll test the float. While the carb is off check that the replacement needle valve is fitting correctly. If there is any dirt in there it won't allow the valve to close and gas will continue to pour in and it will flood even if your float is working. You might consider putting your old one back in if you don't find anything wrong. If you have the carb off you can set the float drop. Remove the front cover with the round sight glass in it. Turn upside down and let the float dangle down against the fuel inlet valve and needle. The distance between the bottom of the float and the chamber should be 7.2mm or 0.283"... adjust the float lever until you get this measurement. This should get your fuel level at the correct height. Quote Link to comment
ggzilla Posted January 2, 2013 Report Share Posted January 2, 2013 And sometimes the little float pivot spacer gets lost, then it works erratically. Quote Link to comment
_chiefjt Posted January 2, 2013 Author Report Share Posted January 2, 2013 Okay I'll adjust the float properly. I don't think I have the old needle, it might be around somewhere. I'll spray it with carb cleaner and put it back together after all the testings done. Quote Link to comment
datzenmike Posted January 3, 2013 Report Share Posted January 3, 2013 And sometimes the little float pivot spacer gets lost, then it works erratically. Specially this!!! Quote Link to comment
_chiefjt Posted January 3, 2013 Author Report Share Posted January 3, 2013 Yes I have the spacer. When I put the float back in I pushed the float all the way up and half way going up it gets harder to push up like there's something holding it. It will still go all the way up but it takes more than floating to push it up. Is this normal or is something holding it from going all the way up? Or is the float not supposed to go all the way up? Could that be pressure built up form the needle going up and closing? Quote Link to comment
ggzilla Posted January 3, 2013 Report Share Posted January 3, 2013 That is normal. The float is not supposed to go all the way up. It is supposed to float about halfway, and the pressure you feel of closing the needle valve is balanced by the flotation. If your fuel pump pressure is too high (more than 3.6 psi) it will overload the needle valve. Quote Link to comment
_chiefjt Posted January 3, 2013 Author Report Share Posted January 3, 2013 I have a Facet 40105 electronic fuel pump. I had it laying around so I threw it on since the old one went bad. It measures from 2 1/2 - 4 1/2 psi. Could that be the problem? Haven't tested the fuel return line yet. Just got done adjusting float. Quote Link to comment
ggzilla Posted January 3, 2013 Report Share Posted January 3, 2013 yes, it could be. 4.5 psi is out of spec for a Hitachi carb. A weber requires even less pressure than a Weber. Quote Link to comment
_chiefjt Posted January 3, 2013 Author Report Share Posted January 3, 2013 A weber requires less pressure than a weber? Do you mean Hitachi? Even so, it was running okay for a while, till now. So I adjusted the float and tested the fuel return line which seems to be clear cause I heard some bubbles in the tank. Anything else? Quote Link to comment
datzenmike Posted January 3, 2013 Report Share Posted January 3, 2013 2.7-3.4 on the 720 electric fuel pump. The needle and valve... is there anything like dirt in there that could be holding it open??? Quote Link to comment
_chiefjt Posted January 3, 2013 Author Report Share Posted January 3, 2013 I did see a little piece of something in the chamber of where the needle closes off. Can't explain it very well but yeah. It was down the chamber where you have to take that bolt off to see down at the needle. The piece was about 3 by 3 mm big. Quote Link to comment
ggzilla Posted January 3, 2013 Report Share Posted January 3, 2013 If your fuel pump is putting out more the 3.8 psi, replace the fuel pump. The Hitachis requires max of 3.8 psi. The spec is 2.7 to 3.4 I think it will run fine on that. Quote Link to comment
_chiefjt Posted January 3, 2013 Author Report Share Posted January 3, 2013 Does anyone know the difference between Weber and Redline Weber? I didn't get back to the Hitachi back on. Putting it on tomorrow cause it got too late. Quote Link to comment
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