Mariner 9.9 4 stroke

rogermarsha

Recruit
Joined
Jun 10, 2006
Messages
3
Ok guys,
I need some serious advice here before I end up taking this motor to the scrap yard.
I have owned this 1996 Mariner 9.9 HP 4 Stroke for about two years and have been working on it almost constantly! All of the problems are hard or not starting. It has what is called a "fuel enrichener valve" or "electrothermal valve". This had to be the stupidest idea mercury ever came up with. Anyway, I have rebuilt the carb, replaced the electrothermal valve, plugs, checked compression, spark, fuel supply, taken the carb apart again to see it I had missed something last time.....3rd time today. All is good jets are clean fuel flows through all ports. A couple of months ago I found that there is one...i will call it a port...that actually had one way fuel flow that I found to be partially plugged, I got it cleaned up and put the carb in place and it ran and started well for several days in a row. I let it set for a week and I was still able to get it started but not so easily. After letting it set now for a couple of months, I went out today and could not get it to start. After a while I started putting my thumb over the intake and I could get it to start and run as long as I kept my thumb on the intake. Remove it...die! Even after the engine was warm it would still not stay running. Finally I pulled the enrichment valve again and checked it out, all looked good. Cleaned it anyway to no avail. Check wiring, Ohm's, all looked good. Finally I put the old enrichment valve back in , same thing. The only way I could get it to run was to pull the enrichener so that the needle was up about 3/8". And it ran perfectly. So I pulled it out completely and plugged the opening with my finger and it ran perfectly again. I expect this will cause cold starting problems since this motor has no manual choke. The only other thing I can think of is something wrong in the stator but it runs perfectly so who knows. I would like to know if I can just plug the hole for the enrichener valve and manufacture a manual choke for this thing or do I just take a BFH to it? :)

Any help appreciated.
Rog
 

-JR-

Petty Officer 2nd Class
Joined
Jun 21, 2009
Messages
133
Re: Mariner 9.9 4 stroke

I am having the same problem ,how did you fix it ?
I tested my valve also 8 ohms ,thats ok
I then applied 12 volts to it ,waited 5-10 minutes as manual says to. Does get warm to the touch as it should,just does not pull in the piston.


As I researched the part ,read not being built any more.
How I fixed mine was just placing a thick 3/4 inch washer between the carb . and electric valve.
I did find out threw testing it on the lake ,not to go to thick on the washer,as it will not run right on the bottom end,I guess that piston valve does not pull in 100% when working or maybe mine started to work with the washer in . Today I installed a thinner shim and unplugged the wires and taped them up.
Started the unit,and test the out but voltage from the connection. Got nothing on DC but switched meter to a/c and got a reading of 5 a/c volts on low idle. Interesting!
Will be testing it out on Cold lake when I go fishing for Lakers this coming weekend

tried to restart the engine this afternoon ,and she would not firer.
has spark and spark plugs were wet ,even tried starting fluid.
They don't build them like they used to be !
engine only has 4 hours on it (1998).....junk
 
Last edited:

-JR-

Petty Officer 2nd Class
Joined
Jun 21, 2009
Messages
133
Re: Mariner 9.9 4 stroke

Went back in the garage removed spacer and removed the piston from the electronc valve and placed it back on the carb.
Then she fired
 
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