old merc

[launchpad]

I have a 1972 80hp merc and it is very hard to start.If I spray some quick start into the carbs it will run on first crank.After that it dies.Does anyone have any suggestions.........."HELP"

 

[timmathis]

Re: old merc

Do not use starting fluid in it!!!!!<br />It will do a lot or harm to it. It has no oil in it.<br />You have a fuel problem. Fuel pump? <br />If you want to spray anything in it use a pre mix.

 

[brad needs help]

Re: old merc

you might try cleaning the carbs and tim is right do not use starting fluid ont it, it takes all the oil out of the cylinder, you will do alot of damage to the motor.

 

[launchpad]

Re: old merc

Thanks for the valuable info.........I am trying to find info on my merc but have had no luck.The serial # is 7146479.I have been trying to find info on this motor such as year but no luck.I need this info to order the parts that I need.Anyone know where I can find the info. Thanks, Al

 

[Motor Boater Bill]

Re: old merc

www.oldmercs.com will provide info and parts.

 

[launchpad]

Re: old merc

I typed in the wrong serial # it is - 7146479 not 7146479.I

 

[launchpad]

Re: old merc

I checked with www.oldmercs.com and had no luck,anyone else have any suggestions.<br /> <br /> Thanks

 

[roger3645]

Re: old merc

Check www.maxrules.com far as I can tell that's a 1981 Mercury made in Canada. As far as starting goes. Do you have a good firm ball after squeezing 4 or 5 times? If not you have a fuel delivery problem. Check gas lines from the tank and on the motor for leaks (Just takes a little leak for the system to start sucking air). Once runing, spray some gas mixture in each carb, should kinda of stall the engine when you spray into each carb. If the engine speeds up, then your not getting enough gas to that carb. Most likely a dirty carb. You'll need to take them off and clean them. Dirty carbs can ruin an engine. No other way to get a good cleaning without taking the carbs off. I found out the hard way.

 

[launchpad]

Re: old merc

Thanks guys for all the great info.Time to do the testing.Again thanks.

 

[davebad22]

Re: old merc

You might be able to find some parts here.

http://www.mercurypartsexpress.com/PartsExpress/ProductSelection/ServiceParts/sphome.asp?CID=

 

[Tuck_72]

Re: old merc

Had the same "no fuel" problem on this 1975 150hp....Come to find out, I didn't pump the bulb enough.....Dad said after the primer bulb gets pressure and is firm, give it a few more slow pumps......Also, a little choke at first to get it all working.....Now fires up fine.....

 

[tashasdaddy]

Re: old merc

parts and manuals

oldmercs.com

 

[JasonJ]

Re: old merc

As Tuck says, you gotta give that bulb a few squeezes after it gets hard. Also, trim the motor all the way in if it has power trim. When you give that bulb those extra squeezes, it unseats the float needles and allows gas to enter the venturi through the main jet. With the motor trimmed in, this fuel trickles into the reed blocks, and the motor fires right up. If you do it with the motor trimmed out, the fuel trickles out of the carbs. Old mercs require a bit of barbaric techniques to get them going. I had your starting problem until I adopted the above stated technique. Now it starts quickly even when it is 29 degrees out. Good luck....

 

[Rex]

Re: old merc

I got the book on the engine but first make sure you
keep gas in the carb's and that will help brake-up the old
build-up of the old gas that smell like varish. If do that for
about 2 to 3 weeks then tap on the carbs with rubber
handle end of a dead blow hammer the floats will come loose most of the time. Then check it out but the other people are right but let the gas work for you it will take a little time!!!!!!!!!!!