volvo dies after running for awhile than it wont start up again

[rwrcrappie]

i have a volvo 170 aq -b out drive 270 about 1970s .motor starts ok but after we run it hard for about 10 to 30 min.we start to troll and it dies.then u have to lift the motor up to get it started again.its very hard to get it running again.most of the time it takes 1 hour before it starts.for some reason u have to make sure the motors out of the water.it runs good in my drive way but when u put it underwater it wont start.but sometimes it runs ok u run it hard and then troll for 7 hours and no problems.but other times it dies and your stuck out 10 mile and thats not good when u cant get it started.it has 3 carbs.like i said if i start it in the driveway i dont have any problems i can run it than turn it off and then it starts right up.something happen when u put it in the water.its hard to start

 

[HorizonblueDK]

Re: volvo dies after running for awhile than it wont start up again

Strange problem.

The only thing I can think of, when an engine dies and won't restart, when warm, is a faulty part in the ignition system, usually the coil.

 

[Senior B]

Re: volvo dies after running for awhile than it wont start up again

You say it has 3 carbs? Or have you put 3 carbs on it? As was said above, sounds like you have an issue with heat & or ignition. Now if your carb is running very rich or flodding itself a bit, you could have an issue with vapor lock which would be more prounounced by overly advanced timing. Check your cooling system You say you don't have overheating problems but it does take a lot to keep the motor happy but poor flow through the exhaust really heats up the engine area and everything else How about ventilation in the engine compartment. Check your timing and set it at spec. Next check your carb mixture screws and ensure they're not in too far. All of these checks I've mentioned cost nothing are quite easy. If it persists bad coils are notorious for failing when too warm. Good luck.

 

[Don S]

Re: volvo dies after running for awhile than it wont start up again

It's very simple to check. When the engine dies and doesn't start, check to see if you have spark.