hard re-start merc.xr6 2003

[kansas drifter]

hi everyone.I'm new to the forum and am hoping to get some help getting my dream boat more dependable. I have a 2003, 22ft. fisher pontoon with a mercury 150 xr6. The motor is a carbureted,oil injected. Here's the problem; I pump the primer bulb and motor starts and runs just fine. I drive out to my drift fishing spot,shut it off for a half hour,it runs ok until the carbs run out of gas.After about 8 pumps on the primer bulb it gets hard and the engine will then start and run just fine. I'v re-kitted the fuel pump, checked the screen in the pick up tube,replaced the gray fuel line [ it was very deteriorated on the inside] and replaced the primer bulb. Another thing i tried was to pump the primer hard after shutting the engine down, doing a 1 hour drift, then starting the engine. This did not help either. What else is there? Any help would be very much appreciated.

 

[Maxz695]

Re: hard re-start merc.xr6 2003

It sounds like a clogged jet tear the carb apart and do a very good cleaaning with all parts removed blow air and cleaner through it before replacing the new kit. Just the fact that the fuel line itself had gunk in it tells me the rest of the carb might not look much better. particals have acumulated inside the carb from the deteriorated hose

 

[j_martin]

Re: hard re-start merc.xr6 2003

It sounds like a clogged jet tear the carb apart and do a very good cleaaning with all parts removed blow air and cleaner through it before replacing the new kit. Just the fact that the fuel line itself had gunk in it tells me the rest of the carb might not look much better. particals have acumulated inside the carb from the deteriorated hose

Naw, there's a filter between the fuel pump and the carbs that would catch any debris.

What you have is a pinhole leak in the suction line somewhere, be it the primer bulb itself, the line, one of the connections including the bayonet connection on the engine, or the pickup tube inside the fuel tank. Could also be an internal line in the engine. It might be aggravated by bad check valves in the new primer bulb.

when it's running, it pulls enough fuel so the air bubbles don't make much difference, though they eventually will, and probably manifest as fuel starvation at WOT and a burned piston or two. When you stop, the weight of the fuel in the line pulls it back into the tank.

On this engine, If you've installed any AtWood or other aftermarket parts, like fuel line or bayonet fittings, discard them immediately and put OEM parts on. It'll save you major repairs.

hope it helps
John

 

[kansas drifter]

Re: hard re-start merc.xr6 2003

Since the engine has 3 carbs I think I'll try finding a pin hole leak first. I did replace the siphon valve at the tank with a plain fitting, and the primer bulb would not work, so I put the old siphon valve back on. I wasn't aware that there is fuel line inside the engine, any ideas on how to check that? It will be about 2 weeks before I can get it all checked out. Thanks for the feedback.

 

[jeffersondodson561]

Re: hard re-start merc.xr6 2003

When you put your fp back together did you make sure the gasket stayed in place while attaching the fp to the block? You may want to verify, and if you pull the fp off again look at the pulse hole (the hole in the block) that the fp attaches to. I have seen this carbon up a couple of times in older OMC's, a pin hole leak could also be a loose hose when ever doing a carb overhauls I always rebuilt the fp's and used p/n 54816311T religioulsy, it is a tie strap and if you examine it closely you will see why about .25 a piece OTC.

 

[j_martin]

Re: hard re-start merc.xr6 2003

If the primer bulb wouldn't work with the standard fitting, there's something wrong with either the fitting (air leak) or the primer bulb.

To find suction line air leaks, add a short piece of clear vinyl hose temporarily between the fuel bayonet and the end of the hose to it. You need a short piece of clear hose and a splice barb to do that.

Under the covers, if there's a leak, it'll be obvious if you watch the hoses while you put pressureon the primer bulb. They won't leak when running, they'll suck air instead.

 

[kansas drifter]

Re: hard re-start merc.xr6 2003

Oh boy... where to start. I think I may have found the problem. I would like to thank j_martin and max for your guidance. I got another primer bulb, and installed that with clear tubing (temporarily). Under the hood, the fuel line was attached to the fittings using zip ties instead of hose clamps, so I installed hose clamps. The bulb still wouldn't get hard, so I checked the pick up tube in the fuel tank, and discovered that it was a loose fit, and would suck air when the primer bulb was pumped. Apparently the manufacturer relies on a pressed on fit to seal the pick up tube, but it isn't good enough, and there's no room for a clamp on the tube and have the tube fit inside the tank. I'm not sure what to do about that at this point. The aluminum to aluminum fittings in the gas tank are a really bad idea, as the threads were stripped, so it involved having to tap new fittings. Thanks again for your ideas and suggestions.

 

[jeffersondodson561]

Re: hard re-start merc.xr6 2003

The fact that your threads were stripped on your pickup doesn't necessarly mean you have an air leak, it is just a fitting. To determine if you have an air leak, pull your pick up out (check the screen) and put a pressure and a vacuum gauge on it (the other end needs to be sealed). Pump the pressure up to about 15-25 psi and it should hold for about 10 minutes and then vacuum test it and pull as many hg's as your test will pull. As far as zip ties, on the pick up, once you have it fixed I would put an Oeticker clamp on it.

 

[j_martin]

Re: hard re-start merc.xr6 2003

The fact that your threads were stripped on your pickup doesn't necessarly mean you have an air leak, it is just a fitting.

:facepalm:

 

[j_martin]

Re: hard re-start merc.xr6 2003

If twere mine, I'd tape the hole to whatever pipe thread would clean it up, then either get a new dip tube assy, cut it to length and install it, or make one by drilling out a compression adapter and fitting copper tubing through the fitting and sealed with a ring and a compression nut. You can solder any adapter you wish to the top of it, probably a right angle 5/16" or 3/8" hose adapter.