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Fuel supply issue

My 1982 70 hp. Merc won't start until I prime the carbs.if I restart immediately sometimes it'll fire up.it runs well once it's started.I throttle it up and choke it but no luck getting it started.I've check and fixed any air leaks between tank and carbs.I've disassembled fuel pump and all looks fine.The bowls on both carbs are filling up prior to starting.primer bulb gets hard and seems ok.haven't had it on the water yet just trying to get it running right.once I prime carbs it fires right up and stays running.Idles fine and throttles up ok Just won't start till primed.thanks for any help .
 
Yes I push key in and lever goes up but I'm not familiar with the enrichment system I can see no physical response inside the carburetor when I do that actually does the outside lever go up it was suggested that I turn the idle mixture up 1/4 turn and that is the adjustment on the face of the carburetors correct?
 
Do you hold the key in while cranking the motor , yes or no ?-----You can not tell by looking if the enricher is working or not.----When the motor is running what happens when you push the key in ?
 
Yes I hold key in while cranking..when i hold it in while running it chokes it.i use it as I warm motor.That's why I think the enriches is operating correctly.if I restart immediately after shutdown it will usually fire up.but after 5 minuets I have to prime cars with spray bottle .I also pump up primer bulb.It idles fair and it was chilly here .Thanks again for input fellas,appreciate it a bunch!
 
The tiny passages in those enrichener circuits are easily plugged up. I suggest you try the "Fastjeff Cleaning Technique". To wit:

With the motor fully warmed up and idling high, put the 'choke' on and leave it on until the motor almost stalls. Let it clear up, then repeat a few more times. That seems to clean out the system.

Jeff
 
My '92 Merc 4 cyl 2 stroke has 2 wm carbs also. It also has an electric solenoid enrichener shaped like a shot glass on the port side of the engine at the same level as the top carb with an electrical wire going in it. It gets activated by pushing in the key and has plumbing with hoses that go from it to the upper and lower carb. When you push the key in or operate it manually by pushing up on a small protruding shaft out its bottom, fuel flows directly to the carbs. If you have someone push in the key (engine not running) and you are at the solenoid, you can hear it activate. My engine when cold will only start with lever up and key pushed in. I found that with the idle screws turned out 1/4 turn extra, it starts when warm with arm up and without pushing the key.
 
Thank for the info RickM46.I see the solenoid,but I didn't see any hose running from it.there a knob on top side that I take is a manual switch to activate tu solenoid.would that be correct?I have to spray gas oil mixture in carbs and lever up with key pushed in to start it.if I shut it off and restart it within a minute or two it will start,nut any longer than that not running I have to spay the carbs again to get it started.it starts immediately when I prime carbs.the bowls are full because I've ck them right after I kill it.Bulb pumps up hard and I have tried to eliminate any air leaks.ill ck in am for hoses off solenoidnthanks again.
 
Totally different system Tim....yours when levers are pulled blocks off air flow thru passage on carb.You can try opening the idle mixture 1/8 turn to see if it helps..
 
Thanks Faztbullet, it's new to me.I tried turning up idle mixture 1/4 turn yesterday to no avail.I might have to open up fuel pump again and see if I missed something.thanks again.
 
Thanks Faztbullet, it's new to me.I tried turning up idle mixture 1/4 turn yesterday to no avail.I might have to open up fuel pump again and see if I missed something.thanks again.
 
Regarding the solenoid and how it works, here is a pic of mine to the right of the fuel pump. The input to the solenoid comes from a hose from the bottom of the float bowl of the upper carb; then there is a hose out of the solenoid that splits into two hoses; they do not go to the carb bodies; instead, each goes to a fitting at the place where each carb is bolted to the engine; fuel dumps directly into intake channels to the cylinders.

You can see the electrical wiring going into the solenoid; when you push in the key, the solenoid opens up and allows fuel to flow from the upper float bowl to the solenoid to the output hoses to the fittings on the block; in addition, when the engine is turning over, I think the vacuum sucks the fuel from the solenoid hoses at the same time.

IMG_0593.jpg
 
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Rick my serial #is 6104705 I might have gave wrong #first post.would this solenoid be in addition to choke solenoid mounted port side and above carbs?it has a plunger that attaches to each carb and moves up when I push key in.there's also a pull knob on top to operate it manually.with key on and pushed in it pulls carb lineage up.no choke plates in carbs.it goes to the carbs linkage mechinizemon htm of each carb.I'm not familiar with this type of choke.but I'm sure it's working because once running it'll speed up rpm when key is pushed in.Just not getting enough fuel in intake to fire her off.thanks again,I'm learning from each post.
 
There is only one solenoid on my engine as shown in the picture. There are no others. I think your configuration is different. When I activate the solenoid with the engine off, gas begins dripping out of the carb fronts; the fittings in the block from the solenoid push enough gas into the head above each carb that a bunch flows back into the carb throats and out the front. With no choke via the solenoid, mine will not start; mine requires practically flooded carbs to start cold. If yours only starts by spraying gas into the carbs, then, maybe the choking mechanism is not delivering enough fuel to the carbs; maybe the carbs need removed and cleaned??

Do you have the shop manual for that engine? The shop manual has helped me immensely in repairing mine.
 
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Ill be getting one soon.right now I can go to library and ck it out .I appreciate your help.I'm going to clean carbs and put new diaphragm in fuel pump.then ck fuel flow and pressure to carbs.Is Delco a good manual.I've got one for my evinrude and it seems to have everything
?ill keep posting till I get this solved
 
I have one published by Brunswick Corp/Mercury for my '92 Merc 40hp; bought it at the same time I bought the engine new; it is one of the best I ever had: many pictures, many step by step disassembly procedures for carbs, electrics and specs, fuel, lower unit, power head, etc. I'm no mechanic but my guess your carbs/cylinders are starving for fuel at start up; mine have to be flooded to get an easy start when cold; only lever up when warm; but when going from warm to cold, lever up and enrichener activation.
 
I got a seloc manual and an integrated manual today Rick.it's cold here today so I'm going to look thru them.Yes cyls are definitely starving for fuel.I may of missed something when I went thru fuel pump.I replace diaphragm this time.It was playable and didn't have any damage that I could see.ill put that on and ck fuel volume and pressure leaving the pump.thanks again
 
Rick your system is totally different than Tims… A carb clean may be the fix and play extreme attention to the idle passages and air hole on top of carb. On the end of lever should be a pad that covers air hole when choked
 
Thank you all for the input.ill get the carbs cleaned up and do as Fatzbullet suggested.I'm starting to grasp the nuances of enrichment system and enricher valve.They are two different processes that aim at achIrving the same end result which I gather is having a richer and larger fuel supply for cold power heads.wouldn't of been able to do this as painlessof if it weren't for your help.once again I really appreciate it.Ill keep posting till goalies is accomplished.
 
I suggest you try my cleaning technique before doing the carbs--it works.

That said, if the hoses from the filter to the carbs are hard and crumbling, cleaning the carbs will be a waste of time. Seen that a lot on older Merc with "Evil-Nol" gas.

Jeff
 
I'm going to try that first.Bring it up to operating temp.then push key in until it sputtered several times.I used carb cleaner like that to try to clear it up but I wasn't activateinng enriched valve.i'll try doing that before I tear down carbs.Thanks for reminding me Fastfeff.the hoses are all in good shape new fuel filter,no Chaffing or cracking hoses.Thanks again!
 
I'm going to try that first.Bring it up to operating temp.then push key in until it sputtered several times.I used carb cleaner like that to try to clear it up but I wasn't activateinng enriched valve.i'll try doing that before I tear down carbs.Thanks for reminding me Fastfeff.the hoses are all in good shape new fuel filter,no Chaffing or cracking hoses.Thanks again!
 
I tried hitting the enrichment solinoid after warming up to operating temp.it seemed to clear it up a littler.At first it didn't effect it at high rpm bit was noticeable at slowerpm rpm.I tried it about a dozen times and toward the end it was noticeable at the higher rpm,but wouldn't restart after 10 or 15 minuets without spraying fuel into carbs.So next i''year down carbs for good cleaning and new needle seat valve and whatever I find that needs replaced.
 
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