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mercury 25xd

L

l_hull

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trying to find the year of the motor the only numbers i can find on motor is A163294.And if any one could help me with a problem.The motor has spark with plugs out but when you put the plugs back in the motor it wont spark anyone plz.
 
Re: mercury 25xd with weak spark wont even try to start on starting fluid

can anyone tell me if there is a way to test the cdi or switch box on a 1985 mercury 25xd:mad:
 
You test the components that feed the switchbox.-------You test the ignition coils.-----------No handy test for the switch box at home.
 
Your coils sound fine - spec is 850-1200 ohms.

Weak spark is most likely a bad stator - the switchboxes on these rarely fail (have been working on these for over 30 years now and have only seen two toasted switchboxes - many stators and triggers).

You can test the stator with your ohm meter as follows -

Disconnect the Black/White and the Black/Yellow stator wires (coming from under the flywheel) from their bullet connectors at the switchbox (should be on the left hand side of the box as you are looking at it - unless someone has messed with it they will be the bottom two wires. Don't confuse the stop circuit, which is also a black/yellow wire, normally the top wire on the side of the switchbox (leave it to Merc to confuse the matter) - at worst you can follow the wires from under the flywheel, normally in a protective sleeve until the last inch or so at the side of the switchbox).

Set your ohm meter to X 10 -

test between the Blk/Wht wire and a good engine ground (any spot with the paint scratched off) - reading should be between 12 and 18.

Change your meter setting to X 1000 -

Test between Blk/Yel and engine ground - reading should be 3.2 to 3.8

Then test between the 2 stator wires Blk/Wht and Blk/Yel (still on X 1000) - should read 3.1 to 3.7

If any of them are out of spec significantly (air temp affects the readings somewhat) or if you have zero continuity between the blk/yel and blk/white, then your stator is probably toast.

You could still have it tested with a DVA (any small engine shop can do that for you, doesn't have to be a "marine" place), but no connectivity between the two stator wires (or tons of resistance) is as close to conclusive you can get in your driveway.
 
ok here we go this seems very strange to me but this is what i have came up with my ohm meter is messing up but did find out.if you take the plugs out the motor fires good put them back in the motor will not fire at all getting new ohm meter to test the rest.this is crazy to me
 
ok little more under standing way to put this i have 4 new spark plugs if i dont put any plugs in the motor and check for spark,it has blue spark,ok if i put 2 plugs in the motor and hook the other 2 new plugs to the coil wires i have no spark
 
kimcrwbr1 said:
What are your readings? I doubt both would be bad did you clean check all the grounds are good?
Click to expand...

yes all the grounds are good the black wire with white stripe on 10x ohms was 22 and zero from black with yellow stripe tested the brown with white stripe and zero tested the brown with yellow stripe zero that went to the trigger
 
i only checked the coils by putting one end in the coil and the other one to the + side of the coil one i got 963 ohns and the other i got around 950 electric start and pull
 
kimcrwbr1 said:
Push button start or key? if it is the key start check to see if you get battery pos to the black/yellow kill wire from the ignition switch if so it is wired wrong or the swich is bad. To kill the motor you ground the black/yellow wire to ground.
Click to expand...

its push button tiller
 
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