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Hard starting 1974 Mercury 1150

S

Schallock

New member
My Mercury 1150 won't start unless I use "Chemtool" as a starting fluid. Once it fires up it will start until it cools down. I have replaced the fuel pump diaphragm and needle and seat in the carbs. I am mixing fuel 50:1 regular gas. Very frustrating...anyone have any suggestions?
 
I believe that motor uses an enrichening valve to flood the motor with gas for starting. If it does, then it's not working correctly.

Jeff
 
Correct...no enriching valve. If I was to add one, would that make a differande, and how cost affective would that be? I don't want to sink a lot of money into this project. I have about four grand invested in this "Ugly Boat" at this point. It seems to me, that hard starting is a characteristic of the Merc' 1150.
 
Simple.-----------Take the time to learn how a PRIMER VALVE used on Johnson and Evinrude works.----------Then take the time to find a used one of those.------They were used for 25 years from 1980 and newer.--------Should be lots of them around used.-----------Once you install that on your motor your hard starting problems are gone !
 
racerone said:
Simple.-----------Take the time to learn how a PRIMER VALVE used on Johnson and Evinrude works.----------Then take the time to find a used one of those.------They were used for 25 years from 1980 and newer.--------Should be lots of them around used.-----------Once you install that on your motor your hard starting problems are gone !
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Thanks for the input. I'll check that out and give it a go. This is the first time I have used a forum for information...worked out great.
 
You can buy the primer assembly on E-bay. Tee it into the fuel supply to the fuel pump line. To shoot gas into the motor, you can use the worthless, motor destroying backdraft fittings on the carbs (if yours has them) or rig up a (steel brake) tube to shoot fuel into the venturi openings. I 'shoot' fuel into the top carb only on my triples (with two carbs) or the top two on my Mark 78 to avoid over-fueling the lower cylinder(s).

Jeff
 
Thanks Jeff... I have been trying to find info on PRIMING VALVES and how they work, with little success. What you have described sounds simple and easy to do. I'll give it a go.

Gary
 
If you don't have the back-drag carbs as Jeff described, you can "tee" into the "balance tube" which are 5/16" (as I recall) lines that go between the reed blocks, on the front crankcase cover. This will dump raw fuel right into the reed block area and she'll light right off.

But feeding via the back-draft fitting is a great idea, and I think your '74 should have that feature.

For fuel supply to the primer, you can tee off the main fuel line. What my good friend "Dr. Frankenmerc" does is drill the top carb, where it is threaded at the bottom of the fuel bowl. He drills all the way thru so fuel can feed from there to the primer. It's a 1/4" thread but he makes a special fitting that will adapt to the small primer line. I suppose you could also drill that hole out and thread for a 1/8" NPT fuel fitting, and size the fitting for the primer line.

The OMC primers work OK, you can also use a Merc primer or any other brand if you can find one. Just mount it on the front cowling support or any convenient spot. You can make a bracket and put it wherever it fits.

Here's a pretty clean 819503 primer on eBay, it's got a rubber-mounted tab for bolting-on. You connect the black wire to ground and the other wire to the wire that currently activates your 12V choke solenoid.

http://www.ebay.com/itm/OEM-819503-...ash=item3f63211067:g:3VgAAOSwB9xXO0px&vxp=mtr

Another style that doesn't have the tab, but you could use a clamp around the body for mounting:

http://www.ebay.com/itm/mercury-mar...ash=item46502a57fb:g:zBwAAOSwubRXDYm0&vxp=mtr

There are new ones listed here at marineengine.com, if you prefer. Just plug the part # into their search engine. Their picture of the part is better, too.

BTW, if you do install a primer, you no longer need the choke shutters or operating linkage.

The primer does have a feature where if it won't operate electrically, there's a black button on the top that, when depressed, allows manual operation of the primer.

The starting drill for primer is to pump the bulb fully, start cranking the engine then depress the "choke" button which will energize the enrichener and fire-off your motor quicker than ever!

HTH.........ed
 
Thanks Ed, Another great idea. I like the thought of having the primer work off of the choke button. I'll be rethinking my approach to the fix. Also, having a part number really helps. Thanks again...I'll let you know how things worked out in a couple of weeks after I have made the installation.

Gary
 
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