Fuel problems??? Something Else??? Help Please!!!

[Tim Ford]

I'll try my best to describe my problem.

I have a 1999 Mercury XR-6 150 HP with 3 carburetors, and an after-market holley red electric fuel pump.

The problems began around the first of June. I had just got my boat back from having it polished, and having the carpet replaced. When I got it back, I took it out for the first time, and it did well at first. It took off normally and ran good. My wife and I stopped at a place to fish for a few minutes, then we decided the water was too rough so we were going to go somewhere else. I went to take off, and the problem began...

So at this time, I pushed the hot foot to accelerate, and take off, but instead the engine began to accelerate briefly, then it was as if it wasn't getting any gas, and it just revved down. I tried again with the same result, several times. Finally I realized that if I just barely pressed the gas I could go just a little bit faster than idle speed, but if I pressed it too hard it would "give out." I was far from the boat dock, and very upset (because I thought the people at the boat repair place messed something up). I finally opened up the battery box, and I noticed that the black wire from the fuel pump to the battery had come disconnected from the battery terminal. I replaced it and the boat ran fine for the rest of the day. I thought that solved the problem, but...

About 2 weeks later, I was out fishing, and I noticed that if I got the r.p.m.'s up above about 4500, the engine seemed to lose power, if I began to decelerate at all from there, the boat would rapidly lose power, and eventually it would just die, unless I quickly pressed the hotfoot down hard again, then it may or may not power up. Also, it began to have the same problem at take off too. I would go to take off, and it would begin to rev, then just lose power (like it wasn't getting gas). I would try several times, and eventually it would take off properly, but still, I could not get it above 4000 r.p.m's or it would begin to lose power and "lag" again.

I assumed that since I was having the same type of symptoms as I was when the wire came off the fuel pump that something must be wrong with the fuel pump. So Tuesday I bought a new fuel pump. I replaced the one that was in my boat with the same one, it is an after-market Holley Red Electric Fuel Pump. I thought surely that would fix the problem, but...

I took it out Tuesday afternoon, and it was doing the same thing. It would lose power several times before it would finally take off properly, and lose power beyond 4000 rpms, and die if I tried to decelerate. I called my dad. He suggested that I needed to replace the fuel filter, and spark plugs. So I did that Wednesday. Took it out Wednesday evening... Same thing.

When I got home I called my neighbor, who is an auto mechanic, and he looked at it and noticed that the fuel hose that was going into the bottom carburetor was kinked badly beyond 90 degrees. He said that fuel might not be getting to that carb, but added that even if it weren't getting any fuel at all, the engine shouldn't be dying like that. Then, Friday afternoon I talked to a man that used to race boats, and he told me that I might have something in my carburetors, and I should remove them and clean them thoroughly.

Well, yesterday afternoon, I put some fuel system cleaner in my gas tank, then I repaired the kinked fuel hose, then I sprayed my carburetors with carb cleaner (but I didn't break them down). I took the boat out yesterday evening, and guess what...

It's still doing the same thing.

The thought crossed my mind, that I might be still getting a bad connection to the battery terminal with the fuel pump wire. So this morning I checked the connection and it looked good.  Then I took the fuel lines off the carburetors to clean them, I noticed that there was a filmy, gasoline colored, residue on the inside of the hoses. I took off each one of the hoses, and blew that stuff out of them, and sprayed some carburetor cleaner through them. I also cleaned the carburetors and cleaned the battery terminals.  I took it out earlier this afternoon, and I thought for sure that cleaning those hoses would solve the problem, but now it's even worse than it was yesterday.

I am clueless now.  I know it's not the starter because the starter is only about a year old. It has a brand new fuel pump, brand new fuel filter, and the hoses and carburetors have been cleaned.

What else could it be???

I have noticed that it idles perfectly, and it sounds perfect when I run it hooked to my water hose adapter, but when I actually get it in the lake, against resistance, that's when it won't work.

It's as if as soon as the engine senses water resistance at the prop, it loses power. Could it be that it needs a new water pump?

Any other suggestions?  Thanks in advance.

[fishfordollars]

I feel for you. The best thing is to take it in and have a competent mechanic put it on the scope and get it correctly diagnosed. You have already spent more than that would have cost you. It's probably a fuel delivery issue, which could include a tank of bad gas, but the only way to determine is to get it checked out. There are so many variables now with the ethanol issue it's impossible to shade tree a diagnosis. Your not the first to start just changing parts. A very expensive way to fix an issue these days. Give us a follow up when you find the problem.

Good luck.

[done]

Question and blind guess type idea, can you take off the prop and see if there is anything wound around in there?

My buds tri-hull has an ancient ('70's) 40 HP 2 stroke. Was having similar stuff happening to his shortly after the motor was rebuilt. On an total whim, we guessed maybe there was some resistance on the prop, and when we took off the prop found a mess of steel line wrapped around the shaft in there. We took it off and so far it has been going well.

[cart7t]

As FFD said,  you're best bet with todays OB's is to have a trained mechanic look at them.  You'll wind up spending (looks like you already have) a bunch of unneeded money trying to shotgun the problem with parts and still not fix the issue.  

[Sfritr]

Look up the old thread about sickly Johnson 150.  Almost word for word I just had your issue.  Took it to the shop, replaced the power pack.  Engine runs like new.  They tried to put it on the Dyno, checked the pump, the reed valves etc.  $285 dollar power pack solved the issue.  Hope that helps.

[Way2slow]

Don't try to compare similar symthoms as being the same problem between a Merc and a Johnson. Totally different ignitions systems.

First thing that comes to mind on a Merc giving that problem would be the stator. Merc motors have high speed and low speed windings in their stator and it could be the high speed windings gone bad. The next thing that can cause the problem is one or both trigger modules. Sometimes, about the only what to eleminate either is to swap them out with a known good one so I would try to find someone that knows Merc motors and has some good used parts that can try in your motor before getting stuck with the bill for new ones.

Could be carbs.

Sorry, I don't know enough about Mercs to offer you any expertise in how to check it out.

[bilgerat]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

[haveme1]

I just had carb work done on my 2000 Merc 150 XR6.  

It was dieing when ever I gunned it to get on plane. I could hit the choke some and it would gradually get there.  I was warned about running lean and the massive damage that could happen.  I decided to go ahead and take it to the shop.  

300.00 later it runs like a dream !  The tec said it was real stopped up.  

  I've bought a manual now so I can save a few $$ maybe.

Spraying cleaner in it wont unstop it I was told.  It just cleans the butterfly and walls not the needles nor jets.

[GLADES]

I agree with Bilerat, run a separate 5 gallon gas tank hooked up to your motor. This will tell you if it is your fuel system or your motor.

If it is your motor, pay the $$ for a qualified mechanic to dialnose and repair. If you just swap out parts yourself, your will just be spending extra money. You will have peace of mind.

If your fuel system is causing the trouble, check your fuel tank vent in both directions.Replace water/fuel separator filter if you have one.all checks out OK, I recommend having your gas tank cleaned and replacing all of your fuel lines all the way to the motor.

Your fuel hoses may appear to be good or new on the outside, but the inner wall of the hose could be delaminating (ethanol damage) under vacuum suction causing a restriction. No way to know for sure so just replace them.

I just went through a similiar problem and my gas tank had pieces of clear silicone that were clogging the pick up tube in the tank.

It was driving me crazy trying a bunch of different things without success. It was taking the fun of of fishing having a baulky motor.

Hope some of this helps.

[Nitro 882]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

Remember to mix oil with the gas in the remote tank.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

[Nitro 882]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

remember to mix oil with the gas in the remote tank.

signed "the voice of experience"

[bass or bass ?]

I was having similar problems with my 1967 Evinrude 80hp. I tried just spraying carb cleaner into the jet orfices but no success Changed a lot of parts too. The carb needed removed and rebuilt. Also, the primer bulb didn't seem to be holding anough pressure, so I replaced that too. It seems to be running right now, but I haven't put it in the water yet to test it under a load, which is where the bogging down showed up.

[Ellesar]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

One of the effects of Ethanol in the gas is that some of the hoses are being eating up inside, leading to pieces of hose in the fuel system. Best to take it in so that the problem can be tracked down.  I've been hearing of similar types of issues because pieces of hose are getting stuck in the fuel system (at different places) and impeding the flow of fuel.

[clipper]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

One of the effects of Ethanol in the gas is that some of the hoses are being eating up inside, leading to pieces of hose in the fuel system. Best to take it in so that the problem can be tracked down. I've been hearing of similar types of issues because pieces of hose are getting stuck in the fuel system (at different places) and impeding the flow of fuel.

Do a Google search on ethanol in outboards and you will get an education on the effects it is having on outboard engines.  A lot of people are having fuel problems with their outboards now.  It not only softens and deteriorates certain rubber components, it also disolves the resin from fiberglass fuel tanks and causes the fuel to absorb water.  One common problem seems to be sticky needle valves.  I have a just tuned motor that is already running rough after only a few tanks of fuel.  

I suspect we will all be needing regular fuel system service as a result of this stuff.  I think the jury is still out on whether the new fuel stabilizers will control the negative effects as well.  The longer it sits in your tank the worse the effects seem to be, so the guys that fish once or twice a week may be better off than us occasional fishermen.  

I have heard you can buy ethanol free gas in Alabama and I only live one hour away.  I may just start fishing Lake Weiss and forget Allatoona.  

I'm no outboard expert by any means but my mechanic is really concerned about it.  

Back to top  

[Ellesar]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

One of the effects of Ethanol in the gas is that some of the hoses are being eating up inside, leading to pieces of hose in the fuel system. Best to take it in so that the problem can be tracked down. I've been hearing of similar types of issues because pieces of hose are getting stuck in the fuel system (at different places) and impeding the flow of fuel.

Do a Google search on ethanol in outboards and you will get an education on the effects it is having on outboard engines. A lot of people are having fuel problems with their outboards now. It not only softens and deteriorates certain rubber components, it also disolves the resin from fiberglass fuel tanks and causes the fuel to absorb water. One common problem seems to be sticky needle valves. I have a just tuned motor that is already running rough after only a few tanks of fuel.

I suspect we will all be needing regular fuel system service as a result of this stuff. I think the jury is still out on whether the new fuel stabilizers will control the negative effects as well. The longer it sits in your tank the worse the effects seem to be, so the guys that fish once or twice a week may be better off than us occasional fishermen.

I have heard you can buy ethanol free gas in Alabama and I only live one hour away. I may just start fishing Lake Weiss and forget Allatoona.

I'm no outboard expert by any means but my mechanic is really concerned about it.

Back to top

Be careful when buying gas that is supposed to be ethanol free, I've been reading about numerous instances where handheld testers showed that "ethanol free" gas really contained 5-10 ethanol in some cases. Seems that the only way to know for sure is to use a hand held tester at the pump.

[clipper]

I'm a diesel mechanic with no outboard experience, but I have a suggestion. Sometimes when we suspect a fuel problem we will run the engine out of a remote fuel can. We use a five gallon can.

If you can SAFELY secure a separate fuel can to your boat long enough for test purposes you may find your problem. This is a good test to determine if you have a bad tank of fuel. If the fuel is crap, no amount of additive will make it better.

I've seen fuel hoses go bad internally also. These can be difficult to diagnose as they look fine from the outside but have swelled on the inside, which restricts fuel flow. Also, especially on the suction (or supply) side of the fuel system, tiny cracks in the fuel hose or leaks at hose clamps will allow air to enter. Both of these conditions will allow an engine to run at idle but cause problems under load.

These are things you can try on your own at little or no cost. At the very least, if you have to take it to a mechanic, you can tell him what you did and help him with his diagnosis.

One of the effects of Ethanol in the gas is that some of the hoses are being eating up inside, leading to pieces of hose in the fuel system. Best to take it in so that the problem can be tracked down. I've been hearing of similar types of issues because pieces of hose are getting stuck in the fuel system (at different places) and impeding the flow of fuel.

Do a Google search on ethanol in outboards and you will get an education on the effects it is having on outboard engines. A lot of people are having fuel problems with their outboards now. It not only softens and deteriorates certain rubber components, it also disolves the resin from fiberglass fuel tanks and causes the fuel to absorb water. One common problem seems to be sticky needle valves. I have a just tuned motor that is already running rough after only a few tanks of fuel.

I suspect we will all be needing regular fuel system service as a result of this stuff. I think the jury is still out on whether the new fuel stabilizers will control the negative effects as well. The longer it sits in your tank the worse the effects seem to be, so the guys that fish once or twice a week may be better off than us occasional fishermen.

I have heard you can buy ethanol free gas in Alabama and I only live one hour away. I may just start fishing Lake Weiss and forget Allatoona.

I'm no outboard expert by any means but my mechanic is really concerned about it.

Back to top

Be careful when buying gas that is supposed to be ethanol free, I've been reading about numerous instances where handheld testers showed that "ethanol free" gas really contained 5-10 ethanol in some cases. Seems that the only way to know for sure is to use a hand held tester at the pump.

I was planning to buy a test kit.