1989 OMC 3.0l timing???

[CodyG]

OK, went to set the timing for my 3.0l in my 89 Bayliner, and the manual says to set at 1 degree ATDC for 90 octane gas, and the OMC place I got my parts says 4 degrees BTDC for 89 octane..whats the deal. Set it yesterday after doing a tune up and oil change and took it out today and it runs rough/bad at top end..back firing and surging like crazy and sounds real rough. It ran smooth as hech at like 15 degrees when we were setting it up and went the wrong way..whats the deal here? Thanks for the help..just want to get it running well till I can find a 4.3l to drop in it (crossing fingers)

 

[Don S]

Re: 1989 OMC 3.0l timing???

What manual are you using?

 

[CodyG]

Re: 1989 OMC 3.0l timing???

Clymers..I know I know..but all my OMC dealer had as he told me he couldnt get me a factory manual, but did read the 4d BTDC for 89 octane gas from one I BELIEVE. Like I said, 5 degrees is a bunch sometimes, so not sure whats up.

 

[Don S]

Re: 1989 OMC 3.0l timing???

Did you set the dwell first? Before setting the timing? Is the mechanical advance working? Are you sure the plug wires are the right firing order?

 

[CodyG]

Re: 1989 OMC 3.0l timing???

set the dwell using a dwell meter then set timing.new plugs gapped to .035 and wires in right order. only really bogs down at attempted top end, at low throttle it runs fine. Idles rough as heck, but told thats to be expected from 4cyl, but 130hp in a light Bayliner should kick pretty well (thinking I am gonna have a rough time finding a 4.3 or 5.0 so I might want to get use to a 3.0..ugh!). I installed a tune-up kit for the distributor, cap was fine, but maybe they sold me the wrong one as it was different looking but I figgured it was just updated version..who knows. I will break out the manual and see whats up again and pull the plugs just to see if they fouled some how. I think I might have a short somewhere cause like I said, if I apply the power trim it cuts out, and I heard static through my speakers yesterday as it was bogging, so who knows. And my OMC dealer is 6 weeks backed up, not willing to miss the rest of the season!