1988 Mercury 150 hp xr4 blackmax

[jackofalltrades]

Hi fellows this is my first login to this forum. I have a 1988 mercury 150 xr4 black max that runs beautifully idling and full throttle out of water with water ears on lower foot. Will crank, time you hit the starter. Let it set for hour or two and overnight you will have to spray gas in carbs to get it to crank. Take it to the lake, go through the same starting procedure. When you push the throttle open it will bog down and smoke pretty heavily. Got 125psi on all cylinders, spark on all plugs and running about 6-7psi on fuel pump outlet. Pumped the bulb up last night and it was still tight this morning and clear inline filter was full. I did clean carbs, checked needle valves all working probably. I'm at wits end please sends some ideas thanks. I bought this boat from my cousin who bought the boat new. He fished in a private club where motors weren't allow to be cranked so this motor has very few hours on it. I have a lot of time invested in this boat. I separated the boat, stripped out everything down to hull and repaired everything. It took me a good year to do this under my garage. The wife is happy its over, but I'm ready to fish if I can get this labor of love running correctly thanks again

 

[racerone]

Re: 1988 Mercury 150 hp xr4 blackmax

They all " run beautifully " in the driveway and sound nice to the ears too. ---Reason being that there is no work for the motor to do.---------Are all the plug wires / ignion wires from powerpacks hooked up correctly ?------Have you checked that the enricher is working properly ?

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Thanks racerone and yes the wires and plugs are correct. The enricher I have no clue as to what that is or where it is, please tell me. thanks

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Ok racerone if you are speaking of what I call the electric choke that shoots gas when you push the key I'm not sure if its working or not. Is this what your calling enricher?

 

[racerone]

Re: 1988 Mercury 150 hp xr4 blackmax

It is just an electric valve that opens when you push in the key.----Pinch off the gas supply to that and see if it improves the running.

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Ok will do, if that's the problem, like I said jackofalltrades master of known

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

will post outcome tomorrow thanks

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Good morning did what you said nothing changed. I took the enricher off and made sure nothing was restricted. After I put the enricher back on and re-priming the bulb it started first try, but after the engine set for a while the same thing happened again. The engine will not start until you physically spray gas in carb. I pulled fuel line from tank and put it in a five gallon can to bypass fuel tank, still no change, same thing happening. I still want to trouble shoot fuel problem before I get into electrical. Its not a educated guess but I still fill like its a fuel carb problem due to it bogging when motor is under load. I changed the bulb I got from wal-mart, I know probably not a good thing but its the only place close and I figure it would be better than the old one. One thing I notice is the bulb will pump up but it doesn't get as hard as I seen on other boats I've owned. Don't have much hair left any help is appreciated my wife said I was to ugly to get away with being bald. So you can see my dilemma ha ha. thanks again

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Oh yea is 6-7psi ok on fuel pump discharge

 

[racerone]

Re: 1988 Mercury 150 hp xr4 blackmax

Fuel bulb must go hard when operated.-----If it does not then there is a leak.---Float valves or diaphragm in fuel pump.

 

[Faztbullet]

Re: 1988 Mercury 150 hp xr4 blackmax

The wally bulbs will not get hard as they only have single check valve they just get a spongey fill..

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Your exactly dead on about the bulb, it just pumps up until a little bit spongy. I'm going to get another fuel pump kit and rebuild again. I took it apart after rebuilding just to make sure I didn't put the gaskets in wrong. I notice both of the flaps didn't look like they were laying as flat as they should be, could just need the pressure to pull them tight. Also I notice the outlet line from the enricher going to the top of the middle carb and out around to the cylinder wall and connect to a inlet port. I removed the line from the enricher and blew thru it could here the air coming out inside the carb, is that normal. I also will get a double valve bulb to correct that. I think I understood your statement to mean the single valve bulb would cause a problem correct.

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Sorry about my slow replies but I work as Director of maintenance by day and RN at night and work on boat motor in between, thank you for your patience and willingness to help.

 

[Dukedog]

Re: 1988 Mercury 150 hp xr4 blackmax

The enricher I have no clue as to what that is or where it is, please tell me. thanks

Not knowing how this works is probably tha reason ya gotta squirt gas in it ta start. If ya haven't figured it out yet let us know and someone will try to explain it..........Its also a clue that it is workin' like it should. Not squirting fuel without be actuated.

 

[Dukedog]

Re: 1988 Mercury 150 hp xr4 blackmax

Also I notice the outlet line from the enricher going to the top of the middle carb and out around to the cylinder wall and connect to a inlet port.

Reread and this concerns me a little. Tha top port on tha enrichner goes to tha port on tha bottom of tha top carb. Tha bottom port of tha enrichner goes to a "T" port on top of tha middle carb. From tha other side of tha "T" it goes to tha top of tha bottom carb............Those are tha only fuel connections for tha enrichner. Nothing goes to any cylinder wall.................

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Wow that's interesting!!! The way I explained it previously was the way it was when I got it. So this maybe explains the hair pulling contest I have been in Ha. I will correct this when I get home. This may explain the vacuum tubing someone put on this engine for fuel lines. I have already replaced all those and cleaned up that mess. I possibly got crossed up replacing those and Mr. Bud light could have caused this that late night when we were working together. I promise I want let him work on this engine again:embarrassed. On a serious note I did check coils and stator with meter this weekend and everything checked out to specs. Also removed each plug wire,one at a time and spark jumps a good inch on all plugs. Thanks Dukedog very good observation. 1 question though what goes on the male port on the left side of the cylinder looking from the back of the engine. I will look a little closer this evening and let you know exactly how its set up. I almost positive the way I explained it previously is the way it is setup up, but you know eye sight isn't as good as it use to be. Come to think of it nothings as good as it use to be physically that is. Thanks guys would be wandering around a lot if weren't for the help.

 

[Dukedog]

Re: 1988 Mercury 150 hp xr4 blackmax

Here is your diagram.....Ya gotta get Fb ta put up tha pdf file.

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

Dukedog your talking to a dummy when it comes to facebook if that's what you mean by Fb not sure how to do that thanks though

 

[Dukedog]

Re: 1988 Mercury 150 hp xr4 blackmax

No, Faztbullet on here!

Tried ta send a pm with a link but iboats won't let tha link go thru. send me an email address, pm if you want, and I'll send tha link.............

 

[jackofalltrades]

Re: 1988 Mercury 150 hp xr4 blackmax

HI dukedog you were correct. The lines coming from the enricher were in wrong place, corrected those according to your instruction. The engine will crank now with a few pushes of the enricher. I have a carburetor kit on the way, the gas will not stay primed up. I believe racerone was correct concerning the fuel pump diaphragm and float valves, because it will not stay primed almost as soon as you pump the bulb up tight you can see the fuel bleed back down in the filter. Tried to so send pm email don't know if you received it or not. I really need that vacuum line schematics. Thanks again for your help. Correction fuel pump kit on the way sorry.