After warm up...it starts to die..... help!

Ok for those of you that are interested I’m trying to trouble shoot my engine problems still.<br /><br />It’s an 2000 Mercury 135 outboard.<br /><br />Here is the problem.<br /><br />I take it to the lake fire it up. I runs great for 10 or 15 minutes. I can go fast, slow, whatever…..<br /><br />Then all of a sudden it is running very rough in idle and kills. When I try to get it some throttle it gets to a point where it should take off…. But sounds like it is getting flooded and kills when I give it more throttle…….. Then it dies at idle (trolling speads) and when trying to give it throttle.<br /><br />But I discovered today if my buddy pumps the primer bulb right at the point that it starts to die (or just before) …..boom it takes off. Then it seams to run fine for a while….. and then starts doing the same thing again…..<br /><br />So it seams to me that maybe I don’t have a good connection from the gas tank….. but why in the heck does it work fine the first 10 minutes?<br /><br />When I pump that bulb it never does it “rock solid” like on other boats I have had but it is not supper “squisheey” either.<br /><br />I guess I can get a new bulb. There is also a filter 10 inches from the bulb and I can replace that as well. (Is this a water separator possibly?) I can replace the hoses as well.<br /><br />Am I going in the right direction here? Any other ideas on what it could be.<br /><br />Any help would be appreciated.

Re: After warm up...it starts to die..... help!

To eliminate your fuel system, or confirm it is the problem, borrow a seperate fuel can and hose from someone and hook it up to your motor. Run the motor again. If the problem persists then you have effectively proven that the fault lies between where you made the new connection and the carbs. You would then have to systematically check each component for leaks.If the fuel pump is more than 2 years old it would be a good time to renew it as the kit is not expensive and can easily be done yourself. If your new connection is made downstream of the water seperator filter then that would be the next thing to look at. When you remove it (unscrew) tip the contents of it into a clear jar and check for water/debris. Do one thing at a time so you don't lose track of where you are.<br />Good luck.<br />Andy

Re: After warm up...it starts to die..... help!

Couple of thoughts on this would be defective primer bulb, gas tank not venting properly or worn fuel pump.

Re: After warm up...it starts to die..... help!

I think I fixed it.... The gas cap was broken and would not lock down.... so I guess too much air was getting in. I replaced it plus all the hoses and primer bulb and took out the in-line filter that was on there. I may add the filter back on after I test it but my engine guy tells me I don't need it....hmmm. Well I'm going to test it out in the next few hours.. wish me luck...<br /><br />Joel

Re: After warm up...it starts to die..... help!

Not likely to be too much air getting into the fuel tank through the cap. This will only allow the fuel to flow easier due to no vacum if anything. More likely the cure is the bulb, blocked filter or degraded fuel lines.<br /><br />My guess was exactly as RodC had mentioned.<br /><br />Hope its ok for ya now...<br /><br />Stan

Re: After warm up...it starts to die..... help!

Replacing the fuel filter will help to keep the trash out, or you will be doing business with your "engine guy"

Re: After warm up...it starts to die..... help!

Well.... it is still doing the same thing. Like I said I replaced all the hose and the bulb and the gas cap and made sure it is venting correctly at least I think...<br /><br />Same deal I get it going and have to have my friend pump the bulb a few times as I accelerate or else it just dies......<br /><br />So whats my next step? Fuel Pump? I know it is pumping but is there a way to test it?<br /><br />What other steps would you take? (Before taking it into a boat shop.... seams like every time I do that it costs me another $1,000.)<br /><br />Thanks for any help

Re: After warm up...it starts to die..... help!

sounds like the fuel pump is bad, change filters and should cure the problem

Re: After warm up...it starts to die..... help!

Heyday the next step would be the fuel pump. Very inexpensive and quite simple to perform. One other thought though. How long is the fuel line between the tank and the engine and what diameter is the hose ? Is this a new problem or something that developed ?

Re: After warm up...it starts to die..... help!

I've only had the boat for about a month and It has alwayhs had the problem. The hose is abou 6 feet I believe....

Re: After warm up...it starts to die..... help!

At 6ft long I wouldn't think the hose could be the problem. Should be 5/16"ID minimum though. Possibly even 3/8" for that big of motor. Are you sure the tank is vented ? Without proper venting the pump will create a vacuum inside the tank preventing fuel from being drawn out by the pump. If you are not sure, loosen the gas cap and see if that makes a difference. Other than that get the pump rebuilt, its cheap and will eliminate one of the variables. Good idea to have it rebuilt every couple years anyway as a preventative maintenance measure.

Re: After warm up...it starts to die..... help!

sounds like venting to me. take your gas cap completely off and try it, or better yet, take the cap off, take the fitting off the end of the hose, put your inline filter back in, and just stick the hose in the tank. see if that helps. if it dosnt, you can eliminate venting. if it does, re-do your tank system.