Aux Tank Set Up?

So, I'm trying to balance the carbs. I rigged up a spray bottle with an adaptor to accept a 1/4" hose to supply the fuel. The first time that I cranked over the bike she ran fast but, I didn't get any leak out of the two over flow tubes. I was getting a small leak into the crank case through carb #2 though. I replaced all of the needle jets to resolve the slow leak problem that I was having. Now I'm getting fuel pouring out of both over flow tubes There is no restriction on my aux tank so, it's, I'm guessing that from the way it acts, the tank switch is in the Prime position. Is this causing my over flow problem? I'm sure that I have I have all of my floats set right. So is my problem a free flow aux tank or, do I still have other problems? What are other folks out there using to restrict the flow into the carbs?

Thanks All
Ken

 

Ken----"other problems" is the correct answer for $100. Although it is not recommended that you ever leave your petcock on the PRIME position, if your valves are closing all the way that still shouldn't matter (if your valves aren't closing all the way, then leaving your petcock on prime will allow the entire tank to drain into your carbs, crankcase, garage floor, hot engine, etc.........you get the picture).


Gotta figure out why the valves are not closing all the way:

a) incorrect, worn, improperly installed, or defective needles, valve seats, or both.

b) floats set waa-a-a-a-yyyyy too high.

c)

 

Thanks Len, I'm now soaking my needle valve seats in carb cleaner, minus the screen covers. I don't think that I did that when I cleaned the carbs last time. Howver, they looked really clean to me but, hey I'll try anything at this point to stop the leakking. If the floats are set way too high and, I have them set at 17.5mm from the gasket base measured to the top edge of the float farthest from the needle hinge. What would be the optimum dry float setting? I am measuring them (using a clear tube off the drain port) less than 3mm from the edge of the float bowl.

Thanks again
Ken

 

The correct FUEL LEVEL for the XJ700 air-cooled bikes with Hitachi HSC33 carbs is 1mm +/- 1mm, so if you're measuring the fuel level at 3mm, then it's way too high (by 50% or 100%, depending on how you like to play with numbers)..................

 

You havn't put the floats back in upside down, don't :lol: it's been done before.

 

Hey Len, you are correct about the 1mm +/-1mm. I'm wondering if when I'm taking my readings with my handy clear tube that, all of the gas has leaked out the over flow outlets and all of my fuel in the bowls are sitting at the gasket line on the bowls. Hey wizard, I thought about that too, you made me double check though. My floats are well hung I just keep getting a flow of gas out the over flow outlets. Thanks though for the help! Got a question though, if the book says that 16mm +/-1mm is the height and, forum common knowledge is 17.5mm where is the optimum setting? Should I just experiment with a higher setting ie. 18.5mm just to get the valves to close?!?

Thanks all
Ken

 

Yes!

 

You have to look at the valve seats to make sure they are shutting off the flow & use the clear tube method to set the heights.

 

OK wiz, now yer just showing off 8O Those carbs must have come right out of the box at some bike show!! I finally got the carbs to stop over flowing. I had to set the float heights to 18.5mm. I thought that I'd never get them to stop hemoraging. I'm leaving the aux tank on the bike for tonight. I have a rubber glove closing off the top. I want to see if I still have a problem on my #2 carb seeping fuel into the intake manifold. Tomorrow I'll try and balance them. I did notice though that, cylinder #3 seemed a bit cooler than the others, I might have another problem. I re-built the coils & I think I might have missed steaking the plug wire on the little spike to make a sure connection. We'll see tomorrow. However, BIG THANKS FOR THE HELP! And, Len, I guess that my post of experimenting with heights was more rhetorical than a real question. As usual, you were right to the point with yer trouble shooter's compass pointing True North.

Thanks again
Cheers all
Ken