mercury 40hp 2 stroke identity +

[sascha]

Well done America you have it all over the Aussies as we don't have this sort of forum available to us. WARNING...VERY NEW TO THIS<br />I have purchased a trihull with a 40hp mercury 2 stroke outboard with more than one problem.<br />1) Does anyone have any idea of the year of this motor, serial number 8046581<br />2) The motor does not lock automatically when placed in reverse.....major spectacle at higher revs!see 4<br />3) The transom has been cut away to obviously take a short leg motor, but been replaced with a long legged motor and water pours into the boat at higher speeds. How far below the keel should the prop be?<br />4) Motor stalls at low revs....Tune?<br />5) Boat will not plane, maybe beacsue of a combination of all above<br /><br />Appreciation in advance for any help

 

[andrewkafp]

Re: mercury 40hp 2 stroke identity +

Welcome to our site.<br />This is a great place for Aussies with boats... <br />and USA is the home of the Merc...<br />Your motor is has an Australian S/N and would be around 1978, but if you look here your will find the appropriate cowling for your year.<br /> http://tinyurl.com/5ogx9 <br /><br />Sounds like the reverse lock cam needs replacement. It is located at the end of the shift shaft in the lower unit and is responsible for engaging the hooks over the locking bar.<br />There are many Merc experts here that will help with running problems.

 

[joblo33]

Re: mercury 40hp 2 stroke identity +

Hi,<br />1. I also can't find a precise year for the serial number and am having the same problem with my Canadian motors.<br />2. Is the mechanism still there? When you shift into reverse a metal clip should lower down and prevent the motor from lifting off the tilt adjusting pin. If the clip's still there make sure the rod that moves it is present and undamaged and if it is but it's not moving try lots of WD-40 and oil, mine was stiff on one of my 50 horse's until I put some all purpose oil on it.<br />3. I don't have much experience with this but I think the prop should be far enought down that the top of the prop's radius is just a little lower than the bottom of the transom.<br />4. Could be a number of things, try fuel system first as it's the most common cause. (carburator(s)) (This is assuming you've already played around with the rich/lean mixture) If not set the mixture so that it almost wants to stall at idle and then a give it a little turn back.<br />5. It could be from bad tuning or the fact that your long shaft is causing drag. First try playing around with the tilt settings by adjusting the tilt pin. If you fix all your problems and it still won't plane consider getting some hydrofoil/dolphins for the leg, they seem to help underpowered motors get a boat up to a plane.<br />This may not be the best advice you'll get on these forums, as I only work on engines as a hobby and most of what I'm telling you is advice I've recieved from the experts on this forum. Tommorow morning some professional mechanics will probably add to or correct what I've said.<br />Eric

 

[sascha]

Re: mercury 40hp 2 stroke identity +

Thanks for the quick response, I will be away over Easter so won't have much of a chance to do any work on the motor.<br />However I will check out all that you have suggested and let you know how I go when I finally get the boat back into the water!<br />I was also wondering if anyone knows where you can get manuals for these motors. <br />Thanks again

 

[sascha]

Re: mercury 40hp 2 stroke identity +

Thanks sincerely for your prompt replies,plenty to go with at this stage and much appreciated. Looking at the link my motor cowling is identical with the 78 merc, but is matched to the 79 with the lack of stripes.<br />Going away over Easter so will not have a chance to do much, but will let you know how it goes when I finally get it back in the water.<br />Just another question, how do you go about procuring manuals for these motors?<br />Thanks again

 

[andrewkafp]

Re: mercury 40hp 2 stroke identity +

You can by them for around $90.00 AUS or get one from a library and "Refer" to it.. <br />But I must warn you that they are copy right.<br />They are published by Clymer.<br />Here are some handy links for parts <br /> http://www.glmmarine.com/pdf/mm.pdf <br /> http://www.dougrussell.com/partscatalog/collections/index.cfm?fuseaction=collectdetails&colid=01

 

[Smedley]

Re: mercury 40hp 2 stroke identity +

try this one too...www.selocmarine.com

 

[Motor Boater Bill]

Re: mercury 40hp 2 stroke identity +

You can also see parts blow-ups online (very handy, especailly until you get your manual) at:<br /> http://www.mercruiserparts.com/selectModels2.asp?type_id=MERC <br />You will need to figure out what year you have, then corss index it to the US serial numbers to use that site. Shouldn't be too hard.<br /><br />On your idle tuning, adjust the carb with the motor in gear. If you adjust with it in neutral, it will stall when put in gear.<br /><br />Mastertech has carb info and wiring diagrams online:<br /> http://www.maxrules.com/carbindex.html

 

[tollys103079]

Re: mercury 40hp 2 stroke identity +

I have a 40 hp mercury and I cannot figure out what year it is any help would be great.

The only numbers I can find are 18758a4 and a couple of part numbers.

Thanks

Steven

 

[achris]

Re: mercury 40hp 2 stroke identity +

This thread is 5 years old!!!!

Please start your own....