1978 500 trigger replacement

[MaxMalmgren]

Hey guys.

I didn't have time to take the boat out last year so of course there's a lot of maintenance that has to happen now...

Anyway, after trying to start it I only get spark on the two upper cylinders, after some reading and testing I found that the trigger lead wires for the cylinders that get no spark is faulty (should be 700-900 ohms across, but it's 58 mohms), so I figured I'd order a new trigger. I tested switching the wires and the problem moves, so it's not the switchbox / stator. Probably.

I'm just concerned about the actual replacement, it seems easy on paper: Remove the flywheel, remove the stator, remove bad trigger, install new trigger, add some grease to the bushings, replace stator and replace the flywheel.

But after that, do I need to readjust the timings / do a link / sync? Or should the old settings still work?
Is it possible to reattach the flywheel misaligned with the crankshaft so that the spark timings are off?

Also, after sitting for a year, should I replace gear oil anyway, do I need to reapply grease anywhere? Anything else?

Thankful for any help...

Serial number 5109842, 1978 500 thunderbolt

 

[Fuddyduddy]

Been through this. The hard part is removing the flywheel. Get (or Borrow) a good puller. Put the parts new and old back where they belong and you shouldn't need to time or reset a thing. Just check your gear oil and if you haven't replaced the water pump impellor when it needed it...... (every 3 yrs.) Do so. A service manual really is a must. Grease the steering cable and the main motor hinge. Yearly.

 

[fastjeff]

You'll have to retime it. I've seen huge differences in where Merc located the magnets inside there.

Jeff

 

[Fuddyduddy]

You'll have to retime it. I've seen huge differences in where Merc located the magnets inside there.

Jeff

Guess I am just lucky. Always the blind squirrel that finds the acorn.