What's the best way to hook up a remote needle valve? The valve has one fuel line fitting on the end opposite the needle, and one coming out the side at right angles to the needle. It would seem to me that the line from the carb should go to the fitting on the end. That way, any suction from the carb would not act on the needle threads, which might allow air to leak into the fuel line. Problem is, the picture on the K&B website shows it the other way (its a K&B 61). The flow would be the same either way. Its sucking in air I'm concerned about. Any opinions?

It's not supposed to make any difference which way you hook it up.

You need to try a real short piece of fuel line over the threaded area as a sealer?
Jim

That's exactly my point w8we! We all (well, lots of us anyway) put that little piece of tubing on the needle to keep air from being sucked in around the threads. That's why I think the remote needle should be hooked up so that the threads are under pressure, not suction. On the other hand, doing it my way might result in fuel leaking out around the needle threads. Maybe I just need to try it both ways and see what happens.

yes, try it and let us know because it is such a problem

jim

...if that were the case (air leaking past the threads),
on a needle valve, then every needle valve ever made
would be defective. I don't think so.

The side inlet is the inlet side for the fuel, and the end
is the carb side. Real simple.

And " IF " there was an air leak through the threads of a
needle valve ( that would remain constant ) probably one
click of richness would compensate for it.

Dave.

Yup Dave, I agree. The side inlet is for fuel from the tank and the end goes to the carb. Its just that the K&B website shows it the other way, as do ads for Magnum and Horizon engines with remote needles . It isn't a big deal, but if there's a good way and a better way, I'll go with the better way every time, which is why I asked the question. As for air leaking in through the threads, you're right again. If its uniform its not a problem. If not, then it can be a problem, as evidenced by all those engines out there with the the little chunk of fuel tubing on the needle to stop the leak. I wouldn't call it a "defect", its just what a carb without a needle o-ring does. Thanks for the reply.

If the threads were going to leak air they would leak no matter which way you hook it up, also on my K&B 100 I hooked it up one way and then changed it and there was no difference, the fuel flow sees a restriction either way.

Hobbsy: Since the pressure on the downstream side of a flow restrictor is less than the pressure upstream, the tendency to "suck air" is greater on the carb side of the needle assy. I just thought that the thing should be hooked up so that the threads were on the high pressure side and not on the "suck" side. Since you tried it both ways successfully, then the answer is: "JUST HOOK THE DAMN THING UP ANY WAY YOU WANT AND GO FLYING FOR CRISSAKES!" Thanks for the help.

does anyone have a pic of this, i am having some trouble keeping my magnum 40 xls running on take off and this might help.