2002 Mercury XR6 will be shot dead soon.

[manleysquail]

I need help. I have a Mercury 2002 XR6 with a power lost, sputter. I took it to a Lic. Mercury Mech., he said " I don't know what the problem is, but I've done all I can do." This after three months, and three trips back the same day I picked it up.
1) I've replace the fuel lines and bulb.
2) I've drained the tank.
3) I've added a water/ fuel seperator.
4) I paid the mech. $275 to clean the carbs.
5) I've replaced the spark plus. I get spark out of all off them.
6) I've checked the fuel diapham
It idols just fine. But when you give her the juice, she sputters all the way up. Once I'm on plane, you can feel a short power loss in the seat of your pants about every 5 to 10 seconds.

 

[mikemac]

Re: 2002 Mercury XR6 will be shot dead soon.

I have the same problem. Did you figure out the reason yet?

 

[j_martin]

Re: 2002 Mercury XR6 will be shot dead soon.

I need help. I have a Mercury 2002 XR6 with a power lost, sputter. I took it to a Lic. Mercury Mech., he said " I don't know what the problem is, but I've done all I can do." This after three months, and three trips back the same day I picked it up.
1) I've replace the fuel lines and bulb.
2) I've drained the tank.
3) I've added a water/ fuel seperator.
4) I paid the mech. $275 to clean the carbs.
5) I've replaced the spark plus. I get spark out of all off them.
6) I've checked the fuel diapham
It idols just fine. But when you give her the juice, she sputters all the way up. Once I'm on plane, you can feel a short power loss in the seat of your pants about every 5 to 10 seconds.

I shot about 8 fuel bugs out of my XR4 when I first bought it. Some were installed by the certified Mercury mechanic. (PO's mechanic)

It sounds like you have a fuel delivery problem. That theory would be verified by rigging a 15 lb pressure gauge to the last (unused) fuel port, probably on the port side of the bottom carb. You must have between 1 and 2 lbs of fuel pressure throughout the operating range. It would usually run 2 or so at idle, up to about 5 at WOT.

I found on mine.
1. Carbs mis-adjusted (mechanic installed)
2. Fuel pump wrong kit, damaged check valves (mechanic installed)
3. OEM fuel bayonet connectors, undersized (mechanic installed)
4. Plugged fuel filter, multiple times (mechanic didn't look into why)
5. OEM fuel bulb and primer, not sufficient delivery (mechanic installed)
6. Wrong (soft) vacuum pulse line on fuel pump (mechanic installed)
7. Now down to the original trouble, sludge in fuel tank.

All of these troubles and their repairs were verified with a fuel pressure gauge.

After repairing all the above, I cleaned the fuel tank and installed a Racor Fuel/water separator, and discarded the original fuel filter. I now run fuel that doesn't have alcohol in it. I also installed a Racor fuel/air separator in the vent line, which helps to limit water intrusion. (and also eliminated a fuel spilling problem)

I also found that the mechanic had set up the timing and carb linkage wrong, so it over-oiled at idle, bogged at take off, and went slow.

When I finally got it right, I had to change props to a steeper one, and also develop a stronger butt pucker.

I strongly encourage you to get it right before you run it much. Fuel starvation is the most common problem that burns down these hot V6 engines.

Don't lose faith on that XR6. Tuned up right it'll run like a scalded dog.

hope it helps
John

 

[j_martin]

Re: 2002 Mercury XR6 will be shot dead soon.

I need help. I have a Mercury 2002 XR6 with a power lost, sputter. I took it to a Lic. Mercury Mech., he said " I don't know what the problem is, but I've done all I can do." This after three months, and three trips back the same day I picked it up.
1) I've replace the fuel lines and bulb.
2) I've drained the tank.
3) I've added a water/ fuel seperator.
4) I paid the mech. $275 to clean the carbs.
5) I've replaced the spark plus. I get spark out of all off them.
6) I've checked the fuel diapham
It idols just fine. But when you give her the juice, she sputters all the way up. Once I'm on plane, you can feel a short power loss in the seat of your pants about every 5 to 10 seconds.

Let me clarify what I've said in the last post.

The mechanic installed an Atwood fuel line and bulb, and Atwood plastic bayonet fittings. Each caused a significant loss of fuel delivery. Plastic bayonet components cannot possibly have a large enough bore to deliver the fuel this engine needs.

The mechanic had gone through the carbs. 3 out of 6 floats were set wrong enough to cause either lean run or flooding.

fuel pump had rubber check valves in them. They need to be the clear plastic ones, and not both (I've seen that, duh)

He put a tygon pulse hose on the fuel pump. (it won't deliver the pulse, but flexes instead.)

At this point it might be worthwhile to do a compression test, just to be sure you haven't done damage yet. Odds are good it's just fine, along with the reeds if it idle's smooth.

hope it helps
john

 

[zbnutcase]

Re: 2002 Mercury XR6 will be shot dead soon.

Those fuel connectors (and bad mechanics) have probably burned up more of these powerheads than any other reason. Most Techs are of the small engine (i.e lawnmower) mindset, not realizing these are 2-2.5L two-strokes turning 5500rpm which requires a LOT of fuel

 

[Faztbullet]

Re: 2002 Mercury XR6 will be shot dead soon.

Hey j, you must have a older Xr4 as they dont use the bayonet fittings on the newer engines, some use the clip on styled after the OMC fitting and if I remember correctly the XR6 is straight plumbed on a 02 model. The Xr6 is bad about chipping reeds and reed petals working loose but it sounds more like a CDM module or a terminal burnt off in a spark plug wire boot causing a miss.

 

[j_martin]

Re: 2002 Mercury XR6 will be shot dead soon.

Hey j, you must have a older Xr4 as they dont use the bayonet fittings on the newer engines, some use the clip on styled after the OMC fitting and if I remember correctly the XR6 is straight plumbed on a 02 model. The Xr6 is bad about chipping reeds and reed petals working loose but it sounds more like a CDM module or a terminal burnt off in a spark plug wire boot causing a miss.

My XR-4 doesn't have a bayonet fitting..... any more. Worthless piece of chit they are.

If I'm messing with fuel, decarbing, etc, I can find a screwdriver and disconnect the fuel line.