Engine only idles while choke is in.

[Therman]

I have a 1988 Evinrude 70 hp VRO and it will start for about twenty seconds then slowly sputter and die, unless I keep bumping the choke or put it in gear. I suspect its somthing with the carbs and I'm hopeing it can be narrowed down.

 

[halfmoa]

Re: Engine only idles while choke is in.

You're not getting enough fuel. Possibly dirty carbs, obstructed fuel lines, or fuel pump issues.

 

[Therman]

Re: Engine only idles while choke is in.

Ok, ill check lines and isn't ther a way to test the pump like pull the fuel lines off the carbs and see if its squirting fuel steadly.

 

[halfmoa]

Re: Engine only idles while choke is in.

Well that's certainly one way but that can be misleading. The way I've always checked to see if the pump is working is to pump the bulb and see if it runs by keeping fuel pressure manually. This may not work with your motor so if anyone disagrees with me please chime in.

IDK what year OMC went to alcohol resistant fuel lines but that can cause multiple issues. That's something to keep in mind too.

Also see this link to rebuild your carbs. http://forums.iboats.com/showthread.php?t=244013 Probably not a bad idea either!

Follow up question, does it run fine when it's in gear? As in not having to keep choking it to keep it running?

 

[halfmoa]

Re: Engine only idles while choke is in.

Alternatively you may have a gasket leak somewhere in the fuel delivery system.

 

[Therman]

Re: Engine only idles while choke is in.

Ya it will stay running in gear with no choke. Also, i just started it and it idle well for over a minute before dieing alot better then before. This engine hasent been ran for 6 years and im wondering if i just need to keep running fuel through it.

 

[halfmoa]

Re: Engine only idles while choke is in.

If the engine hasn't been ran in 6 years and it's 24 years old a carb rebuild is in order, fuel pump diaphram may be shot, who knows how many gaskets have dried out and exactly how old is the fuel? If you're running it with 6 year old fuel that's a problem for sure.

I'd also look into eliminating the VRO system...

 

[Therman]

Re: Engine only idles while choke is in.

The fuel is brand new and the VRO is out. If fuel is getting to carb and pumping bulb doesent keep the engine runing then that eliminates the fuel pump correct.

 

[halfmoa]

Re: Engine only idles while choke is in.

The fuel is brand new and the VRO is out. If fuel is getting to carb and pumping bulb doesent keep the engine runing then that eliminates the fuel pump correct.

I would think so. Hopefully another member will confirm that. The possibility of a blockage between your pump and carbs cannot be overlooked in addition to the other issues I could think of. Honestly I'm leaning toward rebuilding the carbs ESPECIALLY since it sat so long. Think of all the junk that could be in the bowls.

 

[Therman]

Re: Engine only idles while choke is in.

Ya it sounds like a good idea. Is there somewhere i can get step by step dirctions other than a manual for a carb similar to mine i looked at those ones posted above and im still a little confused im gonna look again.

 

[halfmoa]

Re: Engine only idles while choke is in.

It's really not as hard as you'd think...not nearly as difficult as a standard motor vehicle carb. I'm not sure whether the rebuild kit for yours would come with instructions but I'm sure a copy of the service manual will have it. That's money well spent (says the guy who still hasn't bought one).