engine problems
 

Hi all New here. Was just given a 30ft 1979 Reinell. It has twin 228 mercruisers with 350 chev power. Boat passed survey with flying colors and has also been inspected for charter service, altho I wont be chartering. Boat has not been run for approx. 6 months. So out I go with new batteries and bunch of tools, am quite mechanically inclined, install new batteries and start both engines. Very little coaxing required. Run beautifully, smooth, no vibrations at all. After 30 min of high idling 1000 rpm, the port engine shut down and would not start. When it shut down it was like someone turned the key off. After 40 mins. the starboard engine also shut down. Tried to restart starboard side engine and it would fire up for about 2-3 seconds and shut down. As I have been doing some reading on this I would like to eliminate the simple stuff first. I can tell by age,paint and stuff the port coil may be suspect so taking out one today. As for the starboard engine I am thinking gas issue so will take filters and check lines as I suspect vapor locking there. Reason I wrote all this was in hope some of the people on here could encountered some of these thinks and could help me out. Anyone here??
Thanks very much for the long post. Sorry Dave

I always think trying to diagnose engine troubles on the internet is funny. Could be a ton things and you will get ton of guesses. I would suspect gas. The boat is a '79 you say but was the tank stored full or empty? Was it run last year frequently or infrequently and if infrequent is the gas in there 2 years old? If its a '79 how much sludge in the bottom of the tank? Has the ethanol wreaked havoc on those old gas lines? I would do as you are doing and change the filters. If gas is old get it out of there and get fresh gas. If that doesnt help get it to the marina...........

I believe in KISS.... The odds of both motors doing the exact same thing within a few minutes of each other are pretty high

SO.. Check the fuel first... sounds like out of gas! I would check that first. Then check for spark if gas isn't the issue.


Woodsy

Plugged gas tank vent, loosen the gas cap, see if it fixes it.

I agree with both prior posts. If you have see through fuel filters(my favorite for older boats) watch for fuel and not uncommon for the tank float to fail so you could very well be out of gas.Next pull the distributor caps for corrosion,also is it electronic ignition or points. If it's points change over to Pertronix or a metal file

engine problems
 

thanks guys for your tips.
Will check out all, have worked all day on it, changed filters at the carbs and checked main gas filters, fine, changed out coil on port engine made a huge difference and seems to run just fine. Starboard engine changed carb. filter and also coil, made a big difference. Engine has not shut down yet. Still some work to do on port engine as 50 amp breaker is kicking out so will replace tomorrow. Am finding a lot of the things that I do are going in the right direction.
Gasoline has only been in the tanks since January and the are right full and look good. Will keep informed and again thanks for info on things to look for.
Dave

Thankyou will definitely give that a try
Dave

Would like to take to a marina however the reputation of any marinas in this area are suspect. and I would like to think that my experience in gasoline engines could be as good as marina mechanics
Thks
Dave

Good suggestion................... another place to check along the same line of thinking by eliminating overlooking something simple is. Does this boat have electric solenoid fuel tank selector valves for multiple fuel tank sources. Often (in simple terms)(wired into/ along with / in parallel) with the gas gage.

Generic image of what they usually look like.
https://www.amazon.com/Standard-Moto...a-491240730142

Sometimes the valve can be in perfect working order but the (cheap electric) dash panel toggle switch can be broken from corrosion that makes the switch unreliable and intermittent not allowing a steady flow of electric current to the valve or valves effectively shutting off the flow of fuel to the engine.