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Restoring a Rupp Dart super K
#41
Also... Any air leak at hose clamps will cause the pump to lose suction. I fought with this while I was testing a remote fuel purge setup to flush castor oil fuel mix out in favor of synthetic oil mix for storage.

Not exactly what you have, but the principal is the same:


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#42
I have checked the pulse hole, I can see daylight through the hole in the manifold, and the hole in the carb is lined up. I tried 2 different carbs as well. I didn't clamp the fuel lines though... will do that. Lines aren't clamped on the left engine, and it drew fuel right away. When there is a little fuel in the clear line on the right engine, it doesn't even "pulse" when the engine cranks.
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#43
I'd sure like to play with that engine. Use only very good quality fuel hose. Comet Kart Sales has a good hose in the Arrow Kartech black fuel line. I use their bright orange line. It is also soft. I no longer safety wire hoses. I use the plastic snap clamps. Never had a leak.
Kurt has the thought that maybe there's an issue with the second carb you tried, as well as the first. I had that issue in '11 at Bakersfield. I just couldn't get the fuel up to the carbs. Turned out to be a bad carb. It was a freshly rebuilt carb with new diaphragms, needle and seat. We did everything that experienced mechanics can do, and none of us could find an issue with engine or installation. I switched out carbs when I got home, and it ran fine. Ted
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#44
Is it possible that the inlet needles are stuck from storage?
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#45
Possible. If you have a popoff pump/gauge, put it on the carb fuel inlet and see if when you pump it, it holds pressure, then releases. If so, the inlet needle is at least working. Of course, you can take the pump stack off and check the popoff in the normal way. I occasionally need to pop mine loose. It's more common for them to stick when you run castor oil. BE SURE the gasket/diaphragm assembly order is correct. Easy to get them backwards. Here's the Tilly assembly order. TJ
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#46
brian, 
teching out anything requires you follow a straight path .
 starting on one side and working to other is best path
so confirm you've checked each section for possible issues.

on fuel issues you need to check fuel flow from tank to carb first.
 occasionally theres a tank filter in the outlet valve on tank that gets clogged.
next you need to narrow down what isn't working
since engine one fired off perfectly remove carb and install on engine two.
 you already know that  carb is good.

while installing be sure pulse hole lines up.
if engine fires you have a carb issue.
if engine doesn't fire it may be something else.

if you know how to do pop off test carb as that's the fastest test to confirm function.



my best guess is you've probably forgotten something.
when you built the carbs did you flat sand/polish all the flat surfaces?
if not do that first.
did you soak carb gaskets in oil to swell them that often causes micro leaks.
if they've sat a while resoaking gaskets often fixes issues.
is your pump diaphram still good?
like ted said check gasket order.are the gaskets stacked in the correct order. this is usually the #1 issue on failed carbs freshly rebuilt.
if the gaskets aren't new a new gasket set often eliminate odd issues.

did you pull the weltch plug and check the low idle to be clear?
if you're nervous about pulling the weltch plug you can check it by removing idle adjustment needle and gently blowing air down threaded area.
if air comes out both the tiny holes you are all set.
if it doesn't you'll need to clear those two passages. 

another thing to look for is if the diaphram is punched correctly.
on some brand new ones i've found the fuel inlet hole to be as much as 25% covered by overlap.
this is caused by the hole being off to the side a little. oval the hole so the opening is open completely.
 
that's enough for now get back to use with results.

D Cool
Dave L.
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#47
OK, so I got them both running. I replaced the diaphragms in the carb with the ones out of another, tightened everything, put small zip ties on the fuel line as I didn't have any clamps on them. It took a while, it certainly doesn't draw as well as the LH engine, but eventually I got fuel up there. The intake and carb gaskets were installed dry... never heard of soaking them, do you soak in 2 cycle oil? I noticed much better draw after I cracked the idle screw open a little more.

They both tend to stall at full throttle. They run great at 7/8 throttle. Maybe I'm fouling plugs? I mixed 20 oz for 2 gallons, should be roughly 13 to 1. Surprisingly not as powerful as I thought it would be, I suspect there is some tuning needed, and perhaps larger carbs. I have mufflers on the engines as well right now, so I also suspect some significant power robbing there. The kart definitely wants to "push" at higher speeds, the Cheng Shin slicks are new, and maybe will scrub in some more?

Looking forward to dialing it in. My neighbors are gonna hate me... even with mufflers this thing is loud.
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#48
I have the 61 roadrunner kart and twin 580s'. I am collecting parts to assemble. I noticed in the early picks it appears you have a palmini trumpet exhaust! I have one and have been trying to locate another. just curious if you wanted to sell it.
thanks
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#49
nice work  i like it
Richard Stamile
Oceanside NY.
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