Another SM needle question

[rzola]

The brit SUs use standard threads (non metric) on many of the threaded holes and the Hitacis use metric

[dogma420]

Uhh guys, Bruce Palmer who just posted is the owner of Z therapy...if want to ask any of these questions to him, do it.

[dogma420]

bpilati--

The Z isn't in that position anymore, it just looks good, like a woman with her arse in the air...

[Bruce Palmer]

Uh, guys let me clear up another misconception. I am not the owner of ZTherapy, just really good friends with the owners. I have managed over the last 30 years or so to put several hundred thousand miles on Hitachis and SUs before that. My other business interests allow me the time to talk to customers and I hope to bring some counsel to the customers with carb related issues. I can help some of you make intelligent decisions, Steve Epperly is the one who can make these carbs work and a Z car haul the mail. Thanks for the promotion but I like things just the way they are.... When I go past what I can say with a degree of certainty I'll kick the inquiry to Steve. As long as our last job continues to sell our next job we feel we have to be doing something right......

[bpilati]

bpilati--

The Z isn't in that position anymore, it just looks good, like a woman with her arse in the air...

I never thought of it that way, you have a point.

BTW, it must have been interesting rolling off those ramps. :nervous:

[dogma420]

uhh...I don't think rolling down them would work! I don't think you can drive a z up on ramps without damage either...they just work great after **jacking it up with a floor jack** as a stable place to put the car....

[bpilati]

I was trying to be funny.

[cj71z]

Hey guys I'm reviving my post cause I'm having another problem again. I replaced my needles and can't get my car running right. I ended up getting a wierd bug in my back carb. I replaced my needles, needle valves, and put new 1/4 in fuel line from rail to each carb. I blew out all my lines again with pressurized air and also replaced my fuel filter again. I have my carbs balanced and when it's completely warm I get the mixture settings right and she purrs at 700 RPM. When I pop the throttle the car returns to idle, but now runs a little rough. I lower the mixture nut and the idle comes back up. I immediately think stuck needle valve so I tap it with a screwdriver and now it dumps gas all over. I rechecked the float levels and they're both shutting off at 3/8 from the float cover. I put it back together and start it up, now my car idles good. I pop the throttle and now it runs rough, this time my back carb is dry when I open it up. What's going on here, could it be a bad float? I just replaced my mech fuel pump a month ago and it was running great before the new needles.

[beandip]

If when you tap on the float bowl and the carb then floods , sounds to me that the needle valve is at fault. Also it seems the fuel level is a bit high in the bowls. Could there be a fleck of crud in the float valves causing them to stick open , or just plane stick in one position ? Do the floats move up and down freely inside the chambers when you turn the carb upside down ? From what you are describing here this sounds like the problem .

[Arne]

I agree with Beandip that the needle valve and/or float on that rear carb seems to be causing a problem, sometimes sticking open, others sticking closed.

I set my float levels much lower than you did, about 9/16". (The spec I used said 14-15 mm.) I then verified that the actual fuel level in the bowl with the fuel pump running was at 23 mm below the seam between the float bowl and the float cover (as shown in the attached image). I screwed the mixture adjusters all the way into the carb (full lean), and then backed both adjusters out 2.5 full turns. All of my adjustments were based on that as a baseline setting.

[cj71z]

Hey thanks for the responses. I was thinking about crud in there so I checked the fuel filter again and it was gunked up. I cleaned it out and ran it again and it did the same thing. I then looked inside the float bowl and I found some sediment like fine dust. Would particles that small continually give me problems? I also ran another test where I checked the volume of fuel being delivered from the fuel rail to the carbs. I cranked the motor and the back carb ended up with twice the amount of fuel going to it. Could this be a natural case because of increased pressure at the end of the fuel rail being caused by a smaller hole as it enters the fuel return area of the line? The people who owned it before me said they had the tank boiled and relined. When I got it the tank was nearly empty, maybe it rusted again?

Beandip: the floats move freely up and down when I turn the float cover upside down. My floats are the originals, I tested them by seeing if they'd still float in fuel or sink, they floated.

Arne: when I set my floats lower they seems to run out of fuel under acceleration. I'm concerned with the fact that I put 1/4 in. fuel line to the carbs. I think I had 5/8 in. before, but not sure since they were all rotted away. Possibly the smaller size is limiting the flow of fuel to the carbs?

Chris