# Problems with 150 Mercury



## ron9876 (May 9, 2014)

I have a 1994 150 EFI Mercury XRi. I haven't used it much the last couple of years and took it out for a test run. After running a few miles it started having what seemed like a problem getting gas and wouldn't idle or run very fast.

Took it home, removed the old gas, new spark plugs and fuel filter and new gas. Took it out for another test run. It started and idled fine off the trailer but after a couple of minutes couldn't keep it running. It was putting out large volumes of white smoke. It would start and run a few seconds and die again.

I assume that I have a gas flow problem since I tried to run it with old gas and it was running fine when I put it in storage. Does anyone have any good ideas of how to repair this. I was thinking maybe fuel injectors but they look expensive to replace and not something to tackle on my own. Is there anything else that I should try?

Thanks in advance for any input.


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## bountyhunter (Apr 28, 2004)

slow down, \easy stuff first. mix up some sea foam and run it thru, run about ten min then let it sit couple hrs, would not hurt to do this a thew times. sounds like you filled it full of junk gas , others will chime in, but don,t throw money at it till its time.


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## slowtroller (Sep 28, 2011)

Ditto what bountyhunter said, you may need to use several cans.


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## Popspastime (Apr 1, 2014)

Metal tank moisture?? Old existing fuel, Ethanol separated, dirty filter at carb? Dirty carb? These will be your top engine killers. almost forgot.. fuel line dilapidation inside.


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## Gods fisherman (Apr 22, 2016)

This is a good link on seafoam. Good luck


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## UFM82 (Apr 6, 2004)

Your issue is the old fuel. Unless the white smoke is actually steam in which case you have issues other than the fuel system.


If an injector was over-fueling it would be black smoke. If it were over-oiling it would be blue/grey. Is there residue in the hub of the prop? You said you changed the fuel filter and put in new gas but did you purge the lines? Depending on the layout of your boat you could have a significant amount of fuel in the line. I think had you been able to run the engine long enough to clear all the old fuel it would have cleared up. The only time my engine has white smoked has been during a SeaFoam treatment. Once it clears the smoke goes away. 

Do you have two filters? My '93 150 XRi uses two, a water separating filter located in the bilge and then one on the engine. They'll hold a pint each.


How did it sound while it was running?


By the way, just so you know, that engine is one of Merc's best ever. The block is as close to bullet proof as you can get, the fuel system is very robust and even the ecm is solid. It'll run at 6,000 rpm without any issues and it'll start with a bump of the key. Merc performance guys loved those engines. Mine's a '93, hours are unknown, has been in saltwater numerous times, still looks great, pushes my boat along at 50 mph and had cost me very little to maintain. Hang on to it- great engine.


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## ron9876 (May 9, 2014)

Thanks for the input. I will try the Sea Foam.

I will also check the filter before the fuel injectors. The engine ran normal the first time out until it started to stall as though not getting fuel. Basically sounded like it would when idling. After changing plugs and fuel filter it started nicely off the trailer but didn't last long before it stopped. It was missing some, sounded like not getting fuel and then wouldn't restart.

it has been a great engine for me. Have it on a 93 Gambler Intimidator. I am going to put it on the market as soon as I get it running because I simply don't use it enough since I moved north. Hate to lose it but I have started wading creeks/rivers for smallmouth and I tend to end up on the 10 hp lakes when I go out on a boat.


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## fastwater (Apr 1, 2014)

bountyhunter said:


> slow down, \easy stuff first. mix up some sea foam and run it thru, run about ten min then let it sit couple hrs, would not hurt to do this a thew times. sounds like you filled it full of junk gas , others will chime in, but don,t throw money at it till its time.


...and don't trust your alarm/shutdown system. Look back and make sure it's peeing.


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## UFM82 (Apr 6, 2004)

I've found that by adding two gauges to a boat the majority of powerhead-destroying issues will be eliminated. A temp gauge and a water pressure gauge. If you have an engine capable of supporting those two gauges, I suggest adding them if you don't have them. The temp gauge will tell you right away if something is amiss with either the oiling or the cooling system and the water pressure gauge tells you instantly what shape your water pump is in. I installed both on my boat and can see what is going on before the alarms go off. For anyone who wants peace of mind while out boating these two items are necessities.


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## bountyhunter (Apr 28, 2004)

great add on, just think of all the VRO engines it could have saved.


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## UFM82 (Apr 6, 2004)

Funny you say that. I've known/know many people with the system and don't know anyone who has lost an engine solely because of that. Although I did have the VRO pump fail on my '97 50hp because it was disconnected improperly. Other than that, I don't know anyone. But I will say that when I am screaming down the river at WOT the alarms could go off all they want and I'd never hear them. Thus the gauges.


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## fastwater (Apr 1, 2014)

UFM82 said:


> Funny you say that. I've known/know many people with the system and don't know anyone who has lost an engine solely because of that. Although I did have the VRO pump fail on my '97 50hp because it was disconnected improperly. Other than that, I don't know anyone. But I will say that when I am screaming down the river at WOT the alarms could go off all they want and I'd never hear them. Thus the gauges.


I have.
Happened to a guide down on Cumberland during a striper trip a buddy and I booked. Mtr didn't last 3hrs into our trip. And he had just got this mtr back from having warranty work done on the same VRO system. 
No loner mtr or anything from Merc. He was just down the first go round and was gonna be down the second time.
Felt so bad for the guy we paid him his total fee + tip anyway. Of which he didn't want to take but after some coaxing finally accepted.

Needless to say, right in the middle of peak season for him, he wasn't a happy camper.


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## ron9876 (May 9, 2014)

So I checked the final fuel filter and it was clogged. A replacement at locals stores was $309. Not a typo. Small filter. Nothing fancy. Needless to say didn't buy it but I was able to clean the filter and reinstall. I think I found my main problem. So put some Sea Foam in and started to run the motor. it kept dieing after a few seconds. Realized that the ball wasn't staying firm so started looking for leaks. Found a leak from a hole in a brass fitting on a line that comes out of the electric fuel pump. It doesn't look like something that wore out. it is a square brass fitting that has a line from the electric fuel pump on one side and a hole on one side. It was a stream coming out when pumping the ball not just a dribble.

Can't find anything on the internet that tells me what could be causing the leak. Can anyone offer any input?

Thanks for the help so far.


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## fastwater (Apr 1, 2014)

ron9876 said:


> So I checked the final fuel filter and it was clogged. A replacement at locals stores was $309. Not a typo. Small filter. Nothing fancy. Needless to say didn't buy it but I was able to clean the filter and reinstall. I think I found my main problem. So put some Sea Foam in and started to run the motor. it kept dieing after a few seconds. Realized that the ball wasn't staying firm so started looking for leaks. Found a leak from a hole in a brass fitting on a line that comes out of the electric fuel pump. It doesn't look like something that wore out. it is a square brass fitting that has a line from the electric fuel pump on one side and a hole on one side. It was a stream coming out when pumping the ball not just a dribble.
> 
> Can't find anything on the internet that tells me what could be causing the leak. Can anyone offer any input?
> 
> Thanks for the help so far.


A pic. of the fitting/leak may help.


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## Meerkat (Aug 10, 2008)

I would wonder where the junk in your filter is coming from. There are a couple of recent threads on this forum that discuss deterioration on the lining of the flexible fuel line. I have seen this myself on a line only 4 years old. You may want to check &/or replace.


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## ron9876 (May 9, 2014)

I am assuming that the old gas is what caused the filter blockage.


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## Meerkat (Aug 10, 2008)

May not be your problem but here is a picture from the other thread


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## Alaskan (Jun 19, 2007)

If it sat that long unused, I think it is worth replacing fuel line and ball. That check valve could be going bad as well. Also, did you verify your tank vent hose isn't blocked in some way?


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## ron9876 (May 9, 2014)

I think the problem in general was the final fuel filter was clogged. After repairing that is when I realized that I also had a fuel leak. I described it above. Odd to me that there would be somewhere in a motor that is apparently designed to leak in the right situation. I plan to take the electric fuel pump cover off to see if I can find the problem.

Really appreciate everyone's help. I can do the work on engines but I don't have the knowledge needed to diagnose the problems. Thanks.


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## fastwater (Apr 1, 2014)

ron9876 said:


> I think the problem in general was the final fuel filter was clogged. After repairing that is when I realized that I also had a fuel leak. I described it above. Odd to me that there would be somewhere in a motor that is apparently designed to leak in the right situation. I plan to take the electric fuel pump cover off to see if I can find the problem.
> 
> Really appreciate everyone's help. I can do the work on engines but I don't have the knowledge needed to diagnose the problems. Thanks.


Fuel leakage from special brass fitting with hole in it...
Doing a bit of reading, seems you may have some o-ring leakage on your steel fuel lines at the rail allowing fuel to internally leak and circle back to the fuel fitting with the hole in it.
Posts #2 and #4 in this article may help you:

http://forums.iboats.com/forum/engi...outboards/211259-pressure-reg-vapor-separator

FWIW, if you find these orings bad and are around Canal Winchester, there is a place called Hersch Packing that would probably have(or can get) the proper orings. Would naturally have to be gasoline/ethanol resistant and high temp. Orings. You would most likely have to take an old sample oring in for them to get proper measurements. 

Hope this helps...


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## Shad Rap (Nov 10, 2010)

Meerkat said:


> May not be your problem but here is a picture from the other thread


Classic fuel varnish...fuel left in lines...it'll varnish the injectors too.


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