Not running good

[crash1980]

After installing a Dan-Marc 111, doing the "shiny desmog", and adjusting the valves I took it out and at first it did great.  It would hit double the posted limit in no time but then when I started running out of road and slid back down to a cruising 60-65 it runs like crap.  Doesn't act like it's getting fuel.  I stopped for a quick u turn and it didn't act like it had enough fuel to to want to go from a dead stop. 

I'm wondering if the Dan-Marc is causing a fuel restriction.  My thoughts are that there is enough fuel to get it up to speed in the line and carbs but once the extra reserve is used it is starving for what is coming through the valve. 

I was under the impression that the valve used a 1/4 fitting, but it actually uses a 1/8.  I used 5/16 fuel line, plumbed into a brass tee with a nipple attaching a 2nd tee that is plugged in case I decide to add an aux fuel tank.

Any thoughts from anyone? 

[gordonv]

It's been said many times, don't mess with the fuel line length. If you just cut the line and added the valve, then the line has been lengthened. You want it in a continuous slope from the petcock to the carbs, no uphill at all.

Did you have the tank off? Venting from the tank being replaced can also be a problem. The line being pinched, not allowing air into the tank for fuel to drain.

[John Schmidt]

Which model of DanMarc did you buy? You don't want the one with the built in filter, it does seem to restrict flow. I've had mine installed for years with no problems.

[crash1980]

I got the 111. I ended up unhooking the valve and going into the extra tee I had installed and it ran with no problems.

[John Schmidt]

I'll bet your fuel line isn't all downhill from the petcock. Your description sure sounds like the problems associated with that. No reason why the Dan Marc shouldn't work for you.

[The emperor has no clothes]

I got the 111. I ended up unhooking the valve and going into the extra tee I had installed and it ran with no problems.

I used the 121 for the larger orifice size. Did you remove the extra tee from your setup ? Many have used the 111 with no issues. It's probably an issue with too long of line causing it to droop with the tank installed or the extra tee causing a restriction.

[crash1980]

No, I didn't pull the additional tee.  I just removed the plug and installed a new hose the same length as the original and plugged the line still attached to the valve. I wanted to try the most simple solution at a time to see if I could narrow down the problem.