75hp 2 stroke No spark (HELP!)

[jack.watts]

Hi all,

Engine is a Mariner 75hp 3cyl 2-stroke (Clamshell).
After fixing the problem of the flywheel not spinning and rebuilding th estarter motor I have found that I have no spark in either of the 3 cylinders, any suggestions as of what to do here? I have made sure the leads are good and that the contacts are clean before it got too dark to see.

Any advice would be of great help

[Seaflyer02]

Have you checked the kill circuit is not shorting?

[uncle al]

make sure all the earths are clean and tight, then its out with the volt meter staring at the stator check voltages, some one on here will have the figures good luck.

[jack.watts]

Thanks, will check the KC circuit in a minute, also which part is the stator?

[davej]

Originally Posted by jack.watts

Thanks, will check the KC circuit in a minute, also which part is the stator?

Have a look on the net for a switch box test, which you can do with a multimeter. Have you made sure the switch box is correctly coupled. I have a Merc 60 3 cyl , which is probably not dissimilar and I have the oem Merc manual. I could have a look for the test specs in my manual. Dave j

[matt h]

do you have a positive feed from the ign barrel/key to the coils?

[CJL]

Try the service manual - scroll to the bottom of this web page - Boating Resources

Chris

[Nightfisher]

No Spark (All Cylinders). Trigger (under flywheel), Switch Box, Switch Box wiring if removed since last running. If single coil for all three, it's a possibility too. Good Luck.

[uncle al]

is it a red stator or a black one under the flywheel?

[jack.watts]

I'm not sure, I think it's black but will have to check

[9D280]

I'm also pretty sure it's the same (or close enough ) to the 60......

Hunt around for a mercury switch - likley on the stbd side near the top by the coils. the idea of it was to turn the engine off before the prop / water intake cleared the water.

Also check all your HT leads - these things use proper oldschool tech. I found one of mine had completely disconnected between the cable core & the bullet on the connector.....

Also not sure if yours will have an overheat switch - Likely on the cyl head by the top spark plug. If it has one it'll be "close when hot", and wired into the deadman circuit. Run your meter over that as well if present.


Also just to check - you don't have an auto oiling unit sitting by the transom do you?


...Uncle Al beat me to what might be the worst case scenario......

[uncle al]

9D280 only cos i'm a miserable sod, it could be the trigger, switchbox, broken wire some where in the harness.stator buggered.