Old V6 Merc Revival help needed!

General Boats and Motors
1

OK guys, I’ve got a '76 Robalo with the original 1976 Merc 1750 hanging off the back. I know that the best solution would be to trade up to this century’s technology but that’s not gonna happen until I get some extra cash in my pocket.

This motor’s actually got a lot of life left in it and I’ve almost got her running right. Almost.
It will crank right up with no problem and idles fine on the muffs and in the water. Problem is, when trying to get up on plane, it bogs and sounds to me like one of the cylinders might not be firing. (No. 2 cyl. I think)

  • The carbs have been recently rebuilt
  • I’m running off a 6gal tank and non-ethanol fuel
  • I’ve checked the coils and seemed to be getting spark on all 6
  • The power packs were checked and seemed to be OK
  • I switched out stators and that did not solve the problem
  • I’ve checked the wiring and it seems to be OK…

Could the trigger be the cause of the problem? Something else?

It feels like I’m chasing my tail with this thing, any ideas would be appreciated.

Thanks,
Bobby

2

instead of guessing and replacing parts, we need to do some basic diagnostics, and that starts with a compression test.
after that, an actual spark test, and if both of those are good, then a load test and spray a little fuel into each carb while its under load

www.teamcharlestonmarine.com
www.joinrfa.org

3

Thanks Chris, I had some work earlier done at (a place on James Is.), they ok’d the compression and did some other work, but did not test under load as far as I know… I did have spark on all 6 cylinders at one time, but still having issues. I will try a few other things (and start saving some $$) before I can bring in to another professional!

4

you need to double check your compression numbers before you go any farther.
how do you know you are having spark issues?

www.teamcharlestonmarine.com
www.joinrfa.org

5

Chris V,

You are a real asset to this site, if i lived anywhere near Charleston you would get ALL of my business. Customer service is what it is all about and you appear to be stepping up to the plate. I hope you work for yourself.

04’ Scout 185SF / F150