VST or Aeromotive?
02-16-2016, 12:41 PM
#31
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the bulkhead fitting idea still piques my interest though, but......
edit , not to wild about running a hose through cockpit to fuel filler
Last edited by buck35; 02-16-2016 at 12:44 PM.
02-17-2016, 07:11 AM
#33
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02-17-2016, 07:25 AM
#34
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Just a thought because the vst is not one of merc's greatest inventions even when new , bur in a nutshell it's designed to maintain enough pressure to prevent vaporization of the fuel. The diaphragm was revised early on and most were changed or had a tank replaced with the rev version that had a clear hose on top. The fitting that that clear hose connects to on the plenum can become clogged and not vent the excess pressure , weak mechanical fuel pump can't overcome the excess pressure and then you crank run and die when the HP pump sucks the tank dry. Or don't start at all if the diaphragms leaking and not holding pressure and the fuel vaporizes. Very aggrivating. A boost pump kit helps. Merc has a nice kit that's easy to install.
Last edited by Langston; 02-17-2016 at 07:40 AM.
02-17-2016, 07:31 AM
#35
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02-17-2016, 07:47 AM
#36
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Just a thought because the vst is not one of merc's greatest inventions even when new , bur in a nutshell it's designed to maintain enough pressure to prevent vaporization of the fuel. The diaphragm was revised early on and most were changed or had a tank replaced with the rev version that had a clear hose on top. The fitting that that clear hose connects to on the plenum can become clogged and not vent the excess pressure , weak mechanical fuel pump can't overcome the excess pressure and then you crank run and die when the ho pump sucks the tank dry. Or don't start at all if the diaphragms leaking and not holding pressure and the fuel vaporizes. Very aggrivating. A boost pump kit helps. Merc has a nice kit that's easy to install.
I have had some success by putting a wet or iced towel on the vst tank to draw the heat out, but it may have been just the extra wait time. Pain in the arse for sure when it happens.
02-17-2016, 11:27 AM
#37
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How does it bleed excess pressure without a return? Noticed mine started started idling like crap after a couple hard runs, vst float or needle is stuck or the diaphram is ruptured or any other issue inside because there is raw fuel in the clear hose that feeds back to the mech pump. Also is dumping raw fuel into engine, was afraid it was going to wash a cylinder so I parked it for the season
The excess fuel goes to the low side of the pump, suction, and the pressure dissipates as soon as it goes across the regulator. The engine is going to use whatever the engine is going to use, so the less excess that gets pumped the better off the system is because it means you're drawing more fuel the tank.
02-23-2016, 02:51 PM
#38
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have no idea about what or how these Holley pumps would work out ? Just posting to see
http://www.dynosty.com/2016/02/holle...to-new-levels/
http://www.dynosty.com/2016/02/holle...to-new-levels/
02-23-2016, 08:05 PM
#39
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Ordered aeromotive pump,filters and regulator for the project. Starting it soon, thought my tank had an extra bung but it doesn't. Might try the return like Cole did to the low side of the pump or drill and install another bung into the tank. Don't really want to return all the way to the filler hose with a tee, only access to that is up near the helm I believe.
Last edited by camptappakeg69; 02-23-2016 at 08:09 PM.
02-24-2016, 06:41 AM
#40
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the main issue with whole deal was no return to the tank witch kept the fuel hot and lead to the vapor lock deal, dumping it into the suction line of the pump is the way merc did it and did not work, by not returning to the tank 90% of the fuel cooling is not accomplished.
