One of two of my new blown chevy engines shuts off after being run over about 45mph 2600rpm for about 3min. then easily restarts imediatly after shutting it self off. It acts the same when run at higher power levels the other identical engine does not do this at all. ???

carb motors? im not a mechanic but guessing fuel problem. electric/ign problems wouldnt be that consistant and restart every time after shutting down. check carb floats setting and other fuel supply things, in my opinion. good luck

Had a friends boat do something similar this weekend. Speedo hose fell off and pitot hose was spraying the distributor cap.

does it run bad before shutting off..or clean shut-off...if clean shut down sounds electrical to me..what ignition ? have a safety lanyard ?

Could be bad fuel pump. I had one that would idle fine then shut off at about 3500. Do you have fuel pressure gauges?

It shuts down pretty clean and always after about 3 min. over 2600 RPM. 45mph. Fuel pressure is stable about 7-8 psi at the carbs. It sure acts like a fuel issue, but everything seems to be okay. I reset the float drop thinking the needle valves were not open enough with no improvement. The needle and seat are the largest available as per mfg. recomendation. The ignition is all MSD ProBillet dist. blaster coil, 6M box with external rev. limiter chiped at 6500. could a rev limiter malfunction this way?The engine seems to run fine until it shuts down. WOT. it makes huge power but quits at about the same time. )-:

Could be a ignition wire from your coil or dist grounding out. My truck used to do that until i found the tach lead was grounding out. Just a stab in the dark.

switch coils frop one engine to the other,if no change you just eliminated the posability of a coil issue.it seems like an electrical issue,you will find it by the process of elimination.keep us up to date on this problem.

Fixed!!! an intermitently malfunctioning brand new Holley max pressure regulator on the rear carb works fine then suddenly drops to zero psi. I ran a different temperary fuel pressure gauge and caught it in the act. This engines drains a float bowl real fast at 46gph. The oil filled gauge reacted too slow to catch the pressure drop before the engine would quit. A new one is on the way from Jegs a $29.99 fix. The cheapest yet!

sure sounded like a fuel issue,good job finding the culprit and not very often do they end up being the cheap part