4.3 hard to start after run awhile.

Havasujon

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Joined
Jul 20, 2012
Messages
14
I have a 1991 Hurricane Deck boat. The 4.3 V-6 starts easily when cold..runs great,lots of power. After running mid rpms for 20 minutes to an hour or so I drop to an idle to cool for several minutes as recommended in the manual,then shut down to relax. Problem is when we're ready to go again,it takes 30-60 seconds of cranking for the motor to catch. Pumping throttle a touch does not help. Have not tried starter fluid..any ideas? Thanks in advance!
 

Fleetwin

Lieutenant Junior Grade
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Nov 23, 2011
Messages
1,141
Re: 4.3 hard to start after run awhile.

I suggest you repost this to the appropriate outdrive area: MerCruiser, Volvo or OMC.
 

Havasujon

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Jul 20, 2012
Messages
14
Re: 4.3 hard to start after run awhile.

Since it has a Yamaha out drive,I thought other was the right area?
 

Bondo

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Apr 17, 2002
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70,525
Re: 4.3 hard to start after run awhile.

Since it has a Yamaha out drive,I thought other was the right area?

Ayuh,... It is John,... Right when it don't start,... Pull the spark plugs,....

Are they Wet with fuel,..??

Are they Dry, 'n No fuel,..??

Are they Sparkin',..??
 

Havasujon

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Jul 20, 2012
Messages
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Re: 4.3 hard to start after run awhile.

I will check these things and get back to you..Thanks!
 

Ming15237

Seaman
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Feb 25, 2013
Messages
69
Re: 4.3 hard to start after run awhile.

I will check these things and get back to you..Thanks!

If you find no fuel my guess would be you are suffering the great effects of ethanol in today's gasoline. What happens is the fuel basically boils away while sitting in the hot fuel lines as the engine sits for a bit, this is also known as vapor lock. The fuel pump can not pump air, and therefore you must wait for the fuel to re-condense in the fuel lines before the engine will restart.
 

Havasujon

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Jul 20, 2012
Messages
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Re: 4.3 hard to start after run awhile.

Bond-o,Ming..You may have it..Got it to happen,plugs have spark,no gas when it does it..I drive a 1995 Eagle with a V-6 that's doing the exact same thing..crank,crank crank till it starts after running a while. We are having 110-115 temps right now too.. So what can be done for vapor lock? Thanks..Jon
 

Bondo

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70,525
Re: 4.3 hard to start after run awhile.

Bond-o,Ming..You may have it..Got it to happen,plugs have spark,no gas when it does it..I drive a 1995 Eagle with a V-6 that's doing the exact same thing..crank,crank crank till it starts after running a while. We are having 110-115 temps right now too.. So what can be done for vapor lock? Thanks..Jon

Ayuh,... Before ya go blamin' Vapor-lock,...

Make Sure the tank ain't restricted, 'n the fuel pump is pumpin',...
 

Ming15237

Seaman
Joined
Feb 25, 2013
Messages
69
Re: 4.3 hard to start after run awhile.

Bond-o,Ming..You may have it..Got it to happen,plugs have spark,no gas when it does it..I drive a 1995 Eagle with a V-6 that's doing the exact same thing..crank,crank crank till it starts after running a while. We are having 110-115 temps right now too.. So what can be done for vapor lock? Thanks..Jon

Bond-o has a very valid point we don't want to jump to conclusions just yet. There are bottles of ethanol fuel treatment out there which can be purchased at your local boat stores, I would exclusively stick to boat supply stores as this will not be the first time they have seen this, and they will know which additive to give to you. I would try this first. Now automotive fuel systems are a little different, and they have a check valve in the electric fuel pump that back in the day went bad quite often, how you test that on your car is simply attach a fuel pressure gage to the fuel rail on the engine, turn the car on then shut it off, if the gage falls to zero, you either have a leaking fuel injector, (which is not out of the question given the vehicles age) or a bad fuel pump check valve, (which is the far more likely culprit). Can you give me some more specifics on your boat and motor? Is it a IO or outboard? Age of boat? Any other work done in the recent past? And the boat is not fuel injected correct? My guess is that it's carburetor, which is nothing more than a glorified toilet, so don't let it scare you. That being said try the ethanol treatment first, and next time after you run the boat and stop simply pop the engine cover open and let it sit that way, this will help with the temperatures in the engine compartment. If she starts right up you have found your problem. They do make wraps for the fuel lines to help insulate them from heat, but they're is no protecting the carb which is sitting on top of the hot engine with a bowl full of fuel just waiting to evaporate.
 
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