Mercury mercruiser 170 3.7 Engine stops and won't restart

[capt David 1984]

Hello everyone I am a new owner of this boat it is a Regal comodor of 85 I recovered this boat because the previous owner could not take this problem any more the boat works very well he invested more than half of the total value of the boat the two engines work very well cold start starts very well everything seems to work well as I say several mechanics include me because I am a mechanic but I am new to boats several places have worked on this boat and comme up with different diagnostics and do their test and no one finds including me After chasing my tail listening to others I lost money and time I am at the 5th test on the water and once again the boat has stopped working I think the coils are the problem but that's not what everyone else said they told me to check the filters or told me to check if the engine is overheating or that I have water in the tank But that's not it. The first place decided to change the old stator system and install a 12v alternator conversion then the second to install an electronic point kit. Another mechanic diagnosed a gas problem And they redid the carburetors i did rebuild the alternator fuel pump water separator filter fuel pickup tube antysiphon valve i have look for air leak In short everything should be good but always after a run of approximately 20 minutes the engine stops and refuses to start So I let the engine and the coil cool down and the engine starts and runs normally. And start and stop after letting it cool down for a while it restarts just fine but stops again after a while The temperature dials indicate good no overheating but when I check the coils when it no longer wants to start they are boiling hot So I cool them and the engine starts and runs normally.Again I was wondering if anyone else has any ideas on what I should do at this point. I really want to change the coils but I'm afraid I'm missing something. Someone told me that with an electronic point kit I should change the coils for 12v without resistance but I don't want to invest more without knowing if that's really the problem Anyone have any idea?

 

[Bt Doctur]

what happens when you connect a remote tank to the engine?
If it now runs ok,I have your solution to the problem

 

[capt David 1984]

what happens when you connect a remote tank to the engine?
If it now runs ok,I have your solution to the problem This is something I'm considering I wanted to use a primer bulb Between the gas pump and the tank, if I have a restriction it will quickly be visible on the primer bulb which will deflate. And collapses on itself siphoning from the inside?? But I haven't done that yet because when I check the carburetors they are full of gas the gas problem is always the first thing that comes up. Other mechanics tell me but I really rule this out because I have redone almost everything in the fuel circuit But yes I will do it next time on the water and see because that is always the first thing to check and just to really rule out this option after having changed a carburetor and redone the other changed the two gas pumps I am starting to tell myself that it is something else The boat is currently in the water in the workshop, it is impossible to run it for hours but it never does the problem out of the water The problem only occurs after 20 minutes or half an hour and does not do the problem at full throttle just when I slow down or approach the port, harbour

 

[Scott Danforth]

Do not use a primer bulb. It is not USCG approved

 

[Bt Doctur]

test directly to the motor from a remote tank , then report back

 

[capt David 1984]

I can try this but I'm afraid I'll be left stranded again. I need two tanks that will do the job but little space to install the fuel tanks when I talked about using the primer bulbs it was just to diagnose the current tanks by installing them I could clearly see where the restriction problem is if there is one but use an external tank only once the problem is present.? The problem always arises at the wrong time when I come to park the boat without both engines, it is difficult to control and risk damage other boat