Engine Cutting out
 

Hi, I have a 1988 420 HP and the engine cut out today. The engine is getting fuel. It has thundbolt IV and Accel Super Shock Coil. I came back on one engine and when I got back I hit the reset braker and the engine started for a couple min and cut out again. The only thing I did to the engine this year was to change out the MerCruiser Water Temperature Sender. Could a bad temp sender cut the engine out? Please advise.

Did the button click when you pushed on it?
If it did than you have a short or overload somewhere that is blowing the breaker.
IF you don't understand DC power systems get someone involved that does. You don't want to burn up the boat.

A temp sender normally wouldn't keep a motor from running. Guess the press of the breaker was just coincidence.

Need to know what is missing. Your need air, fuel and spark, and appears you have fuel and air, so check for 12V on the coil when the key is ON

you need a mixture of fuel and air in a burnable amount,you need spark at the correct time and the mixture needs to be compressed in the combustion chaimber.now find the missing part.

check to make sure your not losing 12v on the purple ignition wire. Check your ignition switch and the 9 pin cannon plug for connection problems.

Ignition switch ????

Accel Coils are junk IMO.

Its a 1988 carb engine and pretty simple. It needs spark, fuel and air with the correct timing.

Hi, now I can't get the engine started. Its so simple but I can't figure it out. I have fuel, the motor is turning over but won't run. It seems like its trying but just never turns over. So is it the Accel Coil, Thunderbolt Ignition or distributor cap? Please help. Its pissing me off! LOL

No mention of spark
Don't check for spark using a timing light, use a spark gap tester and make sure its white or blue in color

How do I do that?

When you have a spark tester (just like one below), anyone's 12Vdc multimeter, and anyones test light let us now and we'll (OSO members) go thru things 1 by 1 to check and how to check.

$10.00 $13.00 $8.32


https://cimg5.ibsrv.net/gimg/www.off...cef70cc660.jpg
https://cimg7.ibsrv.net/gimg/www.off...55f4ea81cf.jpg


https://cimg0.ibsrv.net/gimg/www.off...987c3611da.jpg

No, not really. Battery's can have a short inside that 'sucks' all the power from the alternator leaving no power for anything else, or just a low powered thing or two. + it can cook your alternator after a bit.

Both are part of a system that keeps all systems with clean and stable power. Both need to be in good working order.

Thanks, I just ordered spark tester, 12Vdc multimeter, and test light. Whats the first thing I should test?

Power at the coil. + terminal. Purple wire. Should be 12vdc with ign key on run.

if you have TB IV:

https://cimg7.ibsrv.net/gimg/www.off...cfa4bc0088.jpg