1991 mercury 2.5l efi

[Trikmit]

I just got this motor and it won't start I am not getting any fuel to the filter just before the fuel rail anyone have any suggestions on what I need to do for this? I am not familiar with this type engine I am mechanically inclined but I have no book or anything on this. Thanks

[Trikmit]

Anyone know where the fuel pump is on this motor it is on a laser 388 le I don't here is fire up when I turn the key on. Also what pump should I replace it with

[CNC_Guy]

Make sure your tether is on, my pump doesn't come on on less tether is hooked up. What model 2.5?

[Trikmit]

Mercury 2.5l efi. What tether and where is it at

[Trikmit]

What do you mean which model? I only see the 2.5l efi is there something else I should see serial number is 0d110626 if that helps

[CNC_Guy]

Need to know if a Laser or horn setup. Safety kill switch tether.

[Trikmit]

It is a laser 388 le I don't see a switch like that anywhere where should it be located

[tlwjkw]

send me an email address and i'll send ya a manual in pdf.....

[Trikmit]

[email protected]. Thank you

[tlwjkw]

be patience.. it takes a few minutes ta open....

that serial number shows ta be a 2.5 "hot rod" horn motor originally!... so its no tellin' what ya got... pictures will help.

[Trikmit]

I will take some and send to your email if that's ok

[tlwjkw]

sure...

[tlwjkw]

early 260 hot rod... forget that manual i sent ya.. sorry, don't have hi perf. manual on pdf.

you NEED TO FIND SOMEONE in your neck of tha woods to show ya tha ropes on that motor, especially being so green..... its NOT A NORMAL motor.... you, at tha very least, need a manual for it BEFORE attempting ta do anything to it..............jmo

[Trikmit]

I ordered one and I have tried to find someone but no luck yet. Anyone in detroit mi area know about this motor that can help me out.

[Trikmit]

Do you know about what hp it puts out? Do you know where the fuel pump is?

[Trikmit]

Hey this is a 2 stroke right? Is the hp 260.

[Trikmit]

How much is the motor worth?.

[CNC_Guy]

You will have to follow the gas lines and see what you will find. Hopefully you will find a screw on water seperator (looks like an oil filter) and between that and the tank you will find the fuel pump. A Bosch 044 will work fine if you need to replace it. The tether clip is usually on the dash or control box. The safety lanyard snaps into its little toggle and the other end on your life jacket. As far as worth, all depends on hours, leakdown, what block etc. I got a factory manual off ebay for 20.00 bucks last week. Yes it is a 2 stroke. Use good oil(like Merc Racing) 32 to 1. A compression test will help determine what octane fuel to use.

[Cervelo777]

If it is a horn motor than the fuel pump will be mounted in the boat. It's a Bosch unit let me find the part number. Go to the diamond marine Web site and read up on the fuel system info.

[tlwjkw]

rated 260.. electric pump in tha boat.. should be able ta hear it with key on...

[tlwjkw]

have you heard this motor run?

[tlwjkw]

pics of his motor... pretty clean for its age!

[CNC_Guy]

Mine is wired so the safety lanyard must be in place and the key on. Maybe his is too.

[Cervelo777]

Yep horn motor. Fuel pump will be mounted in boat. Activated by a relay that provides power when key is on.

[Cervelo777]

Sounds like you bought the motor and didn't get the fuel pump from the seller.

[Cervelo777]

Have you found a fuel pump in the boat yet?

[Trikmit]

I think I found the fuel pump since Whitney said it was after the water filter I seen that in there but didn't know that was the duel pump. I do not seen amy thing for lanyard, I do have a switch on dash that says pump I will try that tomorrow to see if that does anything I thought that it was for a bilge pump.

[CNC_Guy]

If you don't have a lanyard kill switch I would reccomend putting 1 in and using it. Have it kill ignition and pump.

[Cervelo777]

It's possible that some one installed a switch to activate the fuel pump. I considered that but it just adds one more switch to flip when starting your motor. If you find that the pump switch turns the fuel pump on then I would install a relay that would make one less thing to do to start the motor. I can tell you the procedure if that is what you decide to do.

[Trikmit]

I definitely will

[Trikmit]

Please do Whitney you can email me at [email protected]. Thank you all for the help on this. Ftom what I was told this is all still original and was only taken out maybe 10 times up to 1999 2000 then just sat

[tlwjkw]

if that motor has been dormant for 15+ years ya better do a whole lotta checks before ya try ta fire it.. if its still a nic motor, could turn inta a pile a junk ina heartbeat... justa suggestion!... good luck with it.

[vnemous]

Is your name Chad?

[Trikmit]

My name is tim

[vnemous]

Ok guy with same issues on Facebook lol

[luv2gofast]

You could just power the pump directly from the battery to test it. Disconnect the wires first. I'm pretty sure the red wire on the pump is +12v anytime the key is on and the ECU pulls the black to ground. It should run for about 5 sec when you turn the key on then it will stop until you crank the starter at which point it will turn back on. The idea is that it needs to prime the lines when you turn the key on but you don't want the pump running if the engine is not running. Pretty standard with any EFI system.

I agree with tlwjkw that you should at lease pull the plugs, squirt some oil in the cylinders and turn it over to lube up the pistons and walls before starting it. That is a very expensive motor to rebuild and needs to be treated right. That's not your typical turn the key and hammer the gas Merc fishing motor.

What's it on and what was your last boat? I hope it's not your first hot boat.

[luv2gofast]

OOPS! I see it's a Laser bass boat. As I said in the previous post, that's a high maintenance Mercury race motor. Needs rings every 100 hours always run 91 octane or you have to add booster, never run it out of gas and use a high quality full synthetic oil. Unless you have the need for speed you would be much better served with a fishing motor and can probably get a very nice, late model in trade and probably some cash. Those 260's are getting hard to find and that one looks like a virgin. Not many have made it that long without some kind of damage. Also would be interesting what prop and pitch it came with. That will tell a bit about what the previous owner had in mind when he put that motor on the boat.

[Cervelo777]

Tim, I recommend you read the fuel system 101 on the diamond marine Web site.Diamond Marine, outboard racing engines, mercury outboard racing
http://www.diamondmarine.com/ scroll down till you see the button for fuel system 101. I agree with alot of what these guys above have recommended. Only thing different I would say is that my fuel pump runs continuously, and you can hear it when you turn the key the first click. Also, Google waterproof painless relay. Many of us use this relay to power the fuel pump.

[tlwjkw]

all run when key is on, stop when key is off unless its been hacked on... gofast is thinkin' all efi's are like tha laser but no so with horn motor.....

[luv2gofast]

all run when key is on, stop when key is off unless its been hacked on... gofast is thinkin' all efi's are like tha laser but no so with horn motor.....

Pretty sure my 280 horn motor runs as I described but it's a different ECU and I have never had a 260 so I suppose you are right about the 260. Must mot be controlled by the ECU.

[Trikmit]

Ok all I did go through the motor first and lube it up and turnEd it over went very easy I had to replace the starter abd the fuel pump was bad replaced engine fires right up and sounds perfect. Fuel pump stays running with key on never shuts off. So how do I correct that or is that not a concern at this time. I need to get a boat plug thus one us missing then it's time for the water test everything else checks good. We are not going to hotrod just want a decent speed and to take the kids and friends out fishing and some water skiing or tubing

[Trikmit]

What is the fuel ratio for this my local mercury dealer is saying 50:1 but I thought they were 32:1.

[CNC_Guy]

32:1 on 260. They are not the best for tubing, they are made to go fast. Get a low pitch wheel so you don't lug motor. Also only 16 amp charging system so watch your electric consumption.

[Trikmit]

Thanks for the info

[tlwjkw]

Pretty sure my 280 horn motor runs as I described but it's a different ECU and I have never had a 260 so I suppose you are right about the 260. Must mot be controlled by the ECU.

yeah, there was an "optional toggle switch" but don't know of any one that had it in their "factory" harness.. some would add it later... but tha neg. does go through tha ecu only its either "on or off".. no fluctuation or timed... most do away with this with choice of a separate relay anyway..... especially when its tha 16 amp used on either 260 or 280...

[Trikmit]

Hey I seen a few different types of relays which one should I use. And then how will the fuel pump work is it timed and when the motor calls for more,it will work?

[Trikmit]

Also if I was to switch this motor out what is,my best options

[Trikmit]

Luv2gofast what ball park range do you think the motor is worth and how do I find out the prop pitch. The prop is 3 blade stainless steel with these numbers 43 77320a 4 24p then in another spot has 374v6. Does the 24p mean the pitch also found the numbers 9751

[CNC_Guy]

A Promax or 200 EFI would be good. Fuel pump stays on all the time when motor is running, that is what the fuel return line is for, so the pump doesn't deadhead.

[Trikmit]

Anyone know the weight capacity for this boat

[Trikmit]

Anyone know where the water pump is for this motor. I just noticed no water spray out the tubes.

[CNC_Guy]

Water pump is bolted to top of gearcase. It sounds like you need to get with someone familiar with these motors to give it a complete check up. You don't want to melt it, worth nothing at that point. Impellor is probably shot.

[Trikmit]

That's the problem I haven't found anyone abd I an nit comfortable with my local mercury dealer as they keep telling me that it is 50:1 even after I gave them the serial number and explained it is a 2.5l 260 horn motor they said all motors are 50:1. I have ordered a manual but not in yet and local library didn't have it. That is why I was asking to make sure. I wasn't sure how many bolts have to come out on the lower unit to come off. Found some rubber pieces in the side panel not sure if it us the impeller or the pick up tube since this is a lower pick up. Anyone have any info on parts that would be needed. I would like to replace anything in question. And have it on hand, also about how much should the parts be?

[CNC_Guy]

Water pump rebuild kit is cheap, get the metal hubbed impeller. You need to see what size water tube you have so you buy the correct housing. Do a search on water pump replaciement, you will learn some tips to make it easier. I leave it in forward when I drop the case. There are bolts on the side, front and in the back hidden by the round plate bolted up to the anti ventilation plate. Try looking some stuff at Pro Marine. I hope you were able to order the factory manual, the other ones miss alot.

[CNC_Guy]

If you have a racing club nearby, go to a couple of races and try to make some connections.

[Trikmit]

I ordered the factory manual or at least I think I did as it was from my dealer.

[CNC_Guy]

You could have the dealer do all the seals in the gear case while its out. They'd better be able to so that.

[Trikmit]

Anyone no what the part number would be fir the wet pump kit? My local place is closed til Tuesday and the others marinas can not find info for this motor so I was trying to have a part number for them to see if they have one in. Thanks

[tlwjkw]

Mfg Part #: 46-42579A4 (http://parts.promarineusa.com/productdetail/M50/1/1/3319)

[Trikmit]

Does it matter that it us a low water pick up and not ghe side us there anything else that would be needed that this kit wouldn't have

[tlwjkw]

no...

[Trikmit]

Also does anyone know a part number for the 2 steering cables from the wheel all the way back to motor I have,one bad that the precious owner hacked off so only 1,cable to steer it I want to replace both of these. Thanks

[Trikmit]

I want to thank everyone that is helping me with this project it is greatly appreciated.

[CNC_Guy]

You will need to see what brand steering you have. Ride Guide is NLA, you will have to measure the length of the cable and put an ad up for a used 1. Teleflex you maybe able to get a new one. Ebay and here have Ride guide stuff pop up reasonable often. In the end, it may be easier to go hydraulic.

[Trikmit]

What is NLA? Can tge steering operate with just 1 cable. What would be required to go to hydraulic?

[vnemous]

No Longer Available. Nice new Uflex silversteer system is $1000+. No you cant steer with one cable. Please dont take this the wrong way but as far as high performance outboard boating you seem to be over your head and believe me things happen fast in this sport. Be careful how you rig stuff. Keep asking questions and buy a good lifevest and wear it. JMO

[Cervelo777]

Tim,

I feel your pain. No one in my area knows anything about the motor you and I have either. Luckily, it is the most common Hi performance/racing motor used by people on this website. For what it is worth, I think it would be good to have the lower unit pressure tested, or probably better yet, since you have indicated that it has been sitting for many years have the seals replaced. (as mentioned above) If you post pictures we can identify it for you . I am about 6 months ahead of you on the very same journey, and my lower unit blew the seals and I wasted the gears. That is a 2000.00 dollar fix. I have been reading this website daily for two years, before I ended with my 2.5 260, and love it for what I do and I hate to steer you to something different, but if you plan to pull people on tubes, I think you would do good to trade this motor for something designed for more standard use. A 225 promax is a very fast motor, but designed by Mercury for the recreational boater, you can probably trade your motor for a very good 225 promax. I wish I had one to trade you becuase it sounds like you may have a very nice motor now and many would love to get their hands on it.

[Trikmit]

Does anyone gave a good video or instructions for replacing the,water pump? I took it apart today to find almost new parts but looks like it was put together wrong as parts are melted together anf the lower housing to the upper housing had,a,small gap on one side. I was suppose to have my kit today but it won't be in until tomorrow sometime. I found a diagram but it onky shows me the numbers snd no description of ehich gasket us which. Thanks in advance

Tim

[CNC_Guy]

youtube has some vids. Watch a couple of different ones to make sure you get it all.

[Trikmit]

I did do that Dave I was just wondering if anyone had directions. I have one question in the lit the top housing is there a seal that goes inside the top and then the seal that sits on top of the water pump?

[luv2gofast]

I did do that Dave I was just wondering if anyone had directions. I have one question in the lit the top housing is there a seal that goes inside the top and then the seal that sits on top of the water pump?


If the impeller or housing looks melted it's because someone ran it on the trailer without water hose connected. It only takes a minute to destroy the water pump running it dry. There is a rubber square ring that slides down on the drive shaft against top of the pump housing. If you got the whole kit it will have a new housing and also that square ring. be sure to turn the drive shaft clockwise as you push the housing over the impeller. Makes it much easier to get on and sets the vanes in the correct direction. Also helps to have an extra person turn the flywheel a bit as you lift the lower unit back up into the motor to help line up the splines. It should go all the way in when lined up correctly. Tricks are to make sure the shift coupling engages with the spline on the front of the LU and there is a plastic sleeve that sits in the water outlet of the pump housing to help guide the brass tube into the top of the housing. I always grease the gaskets to keep them from sticking. Makes the next change much easier. That's about all I can think of but like others have said, that is a factory "race" motor and fragile, expensive to repair, hard to find a standard Mercury shop that even knows that they exist let alone has parts. It should be a very potent combination with the right prop and motor height and will require much seat time to learn how to run it right. For sure you can't run any big outboard safely with a single steering cable and for sure not that hot rod. I am surprised that the prop pitch is 23. I would expect 26 or 28 so be careful and don't over rev it. Take it easy working the speed up slowly and when in doubt trim it down! Lots have gotten in trouble with too much up trim but no one has blown over from too much down trim. Good luck and keep reading posts on this site. There is much to learn!

[Trikmit]

Does anyone know the capacity of the laser 388 le? My wife is tripping about how many can be in the boat and she won't listen to me so if anyone knows please post it so I can show her,and easy her worries. Thanks

[Trikmit]

Also I have morse controls steering g dual cable e300619-192in 4612. Which I believe is the 12ft cable is the teleflex ss15212 the correct unit and is it a good unit or are there any other recommendations. Also anyone in the Detroit area that would be willing to help me on this engine oh I also receive the book from the previous owner and this is a 2.5l efi 280 offshore. She said it was run maybe 10 times the gentleman bought the boat to go into racing but he got in trouble and went to jail and then died shortly after getting out boat has been sitting since 2001 and it as only used for fishing. I was thinking of selling the motor or trading it for more our use any suggestions and what I could get for this motor with it being so clean and low hours??