Mercruiser 3.7 wont get spark.....

Hello everyone.... Im new to this forum but have found great help on many forums out there. Having trouble with my boat so i figured it wouldn't hurt to try here.

I have an 85 Wellcraft 180 elite with a merc 3.7 (488). The last time we had it out last summer it ran good half the day. But latter on through the day i would find it falling on its face. Full throttle would have problems getting up on plane. Figured it was time for some maintenance..... Boat has been in my family since 1986 and in the last ten years excluding last year only was out 7 or 8 times. Only 526 hours on motor.

Brought it out this year and changes the fuel filter and it still had the pores rock one in it. Replaced it with a paper updated model. Pulled plugs out of it and they were in bad shape. No oil or anything. But you could tell they were old and needed replacing. The plugs that came out were motorcraft ARF32. Napa gave me some AC delco R42TS and said they were compatible but were a little longer.

Put them in and couldn't get it to fire. Started trouble shooting and found there was no spark at plugs. Then i tested the wires and found no spark there. I tested by holding to block and turning engine over. Then i took the distributor cap off and checked the points and rotor. This is where i got lost. I am used to all this distributor less stuff and fuel injection....:facepalm:

Everything looked great though. Cap looked brand new. Not even any dust. Took it to a mechanic shop and he said that everything looked great inside of the cap and to put it back on. So i did. Next i jumpered the coil to test if there was spark and i could get a faint spark. Not sure how much is needed. Checked firing order and it was right. Didn't think it would be but doubled checked anyways.

Im pretty mechanically inclined and have worked on all my own stuff but being born in the 80's... I haven't ran into carburation and points much...

Any help would be appreciated. Thanks in advance!!!

Re: Mercruiser 3.7 wont get spark.....

Replace the points, most likely glazed over.can be sanded with a finger nail emery board for testing for spark,
Plenty of videos of installing and adjusting points systems.

Re: Mercruiser 3.7 wont get spark.....

I will chime in with my recent knowledge of the 470 (3.7) as BT said check the point and replace them if they have to been changed in the last few years should be part of the beginning of the year start up. Also check ALL your connections better yet clean them everything from the key switch to starter coil dizzy. That fixed mine. Stony loam is of big help see some his post as well as mine.