Boat Easy Then Hard To Start

[DayCruiser]

1990 Merc Cruiser i/o 130hp 4 cylinder<br />Plugs 1 year old<br />PLug wires new--bought this past weekend to try and eleviate the problem. Guages show no other problems<br /><br />Ok when starting out the boat starts right off and then runs smoothly for a couple of hours.<br /><br />Then when shut off for a swim it is hard to start. To the point of almost running down the battery. I have found if I take the carb cover off and fiddle with the flipper thingy in the carb--then the boat will start. I have done this a couple of times with success. But the boat runs rough after that and then tries to shut off when slowing down to go under bridges and then sometimes just shuts off when docking. THis last time after I put the new spark plug wires in it didnt shut off when docking. But it was still very hard to start after the second shut off.<br />I have a water seperator that was checked a month ago and it showed no signs of water.<br />Seems that after the motor heats up the problems start. Runs at 140 degree's average.<br />Vapor lock or what? This can be unnerving as we all know. How to I remedy? Carb shows signs that its getting plenty of gas. I run Shell V power 89 octane. Should I lower the octane to 87?<br />Thanks in advance!

 

[Bondo]

Re: Boat Easy Then Hard To Start

I have found if I take the carb cover off and fiddle with the flipper thingy in the carb--

Ayuh,............<br /><br />Fix the Choke,+ Your problems will Go Away............

 

[DayCruiser]

Re: Boat Easy Then Hard To Start

thanks!<br /><br />How? Something I can do or one for the shop?

 

[DayCruiser]

Re: Boat Easy Then Hard To Start

The first time I bumped the choke it was stuck in the upright position. I just bumped it to the left

 

[SeaSkwurrel]

Re: Boat Easy Then Hard To Start

Do you know what type of carb you have?

 

[bigbrownbuku]

Re: Boat Easy Then Hard To Start

pumping the throttle will overcome a stuck open choke. check your accelerator pump is working, look down the venturi and goose the throttle/key off, fuel should squirt. check the screen at the fuel line union at the carb, its often overlooked. visually inspect all the connections, hoses and clamps on your entire fuel system. does your fuel pump have a metal bowl underneath? if so remove and clean it. youll likely need a new gasket to refit it.

 

[DayCruiser]

Re: Boat Easy Then Hard To Start

Thanks for the info Ben. I will check all those out. Maybe its not the Choke because I pump the throttle<br />Its not a EFI carb I know that.<br />It could be the 89 octane V-power shell gas causeing it to run hotter and vapor lock. Maybe when I raise the doghouse it cools off quickly? I switched to this gas because i went along the interstate and bought Race track gas and it really ran rough. I think I will check out what you said Ben and switch gas too. Start using 87 octane form another station I trust

 

[DayCruiser]

Re: Boat Easy Then Hard To Start

I think I have solved the problem.<br />The first time I cut the boat off to go for a swim it was hard to start but not too bad.<br />The second time it just wasnt going to start at all and we were drifting close to shore and paddleing lol. Well I throttled it all the way down and goosed it a little from that point and viola!--it started. Next 2 times I did the same thing and it started right up. Before I was pumping the throttle at about the half way point not wanting to flood it. But I guess at 95 degree and very warm waters you dont have to worry about that very much.<br />I also bought a new gas/water seperator(the other was a year and half old) and switched to 87 octane from 89 Vpower high detergent gas. Of course the old gas will have to be run out completely but the mix and the new seperator sure helped it run better(as well as the new spark plug wires bought last week)<br />All in all it was a great day on the water! There is nothing much like it<br />Thanks again for all your help. I hope my throttle sequence helps somebody else out there who is experiencing vapor lock