im having trouble timing 87 mercruiser block and head with 2002 ignition system, est

[potatoe]

hello, i have a 2002 bayliner capri 175. i picked it up on a good deal. the owner did not properly winterize it after 2 summers of using it. and cracked the block. he then held onto it for a few more years until i got it. i eventually put in this 87 3.0, originally with conventional ignition. the only thing i did not change was the 87 starter and alternator because,the flywheel is different, but everything else fit. the timing was set by ear (listening). and runs good. but it is not timed correctly. i have got answers through the grapevine anywhere from 12 degrees before top dead center, to 6 degrees after top dead center.
i will tell you this. the 87 valve cover that was removed and replaced with 2002 valve cover read on side, specs, ignition timing 6 btdc. that was with the conventional timing in 1987 engine and set-up. but when i look up newer est ignition timing, it says 2 degrees atdc. i dont know if that matters. but i cant get the mark to line up with any of these answers.
i am following the steps by jumping white wires off distributer, and bypassing the switch. ive read the directions ,and watched videos, but i cant seem to get this. my questions are. what is the true timing setting for this older engine, with the newer est ignition? and is there anything else that i need to do to get this tuned in? the forth is coming in 4 days and we planned on dropping it in the bay to watch the fireworks. i hope to get it running properly by then. i just put in new cap, rotor, plugs, refurbished carburater. and new timing cover(was rusted and leaking oil). i hear thats a popular problem with 3.0 engines, due to being right under the waterpump. i have pictures, but cant seem to post them. if anyone could help me there, i will send what i have. thanks

[Don S]

You need to set the timing at 1° BTDC on that engine while in base timing mode. When you bring it out of base timing, it will not be at 1° BTDC, that is just the number to set it at.

and new timing cover(was rusted and leaking oil). i hear thats a popular problem with 3.0 engines, due to being right under the waterpump.

Only a problem because the water pump leaks. If the leaks were fixed when it started leaking the cover wouldn't rust through.

[JWebber]

Engine up to normal temp when doing the est timing procedure??

[Don S]

Engine up to normal temp when doing the est timing procedure??

The timing doesn't care if it's cold or warm, but it will idle easier in base timing mode when warmed up.

[JWebber]

Well thats what I was trying to state, to get a better timing reading etc... I hate jumpy readings..LOL!

[potatoe]

i try to get it to the 1 degree btdc, but motor just runs uneven and dies out. is there anything else that i could try before taking it into the shop? thanks

[Don S]

If the idle rpm is too low, it will die. You may have to keep the rpm up around 800 rpm while adjusting timing.

[potatoe]

the idle does not change at all when i jump two white wires together, and bybass switch. it stays totally the same when i do this procedure. timing does not advance when unplugged either. when it does advance, what degree does it advance too? i think there might be somthing else wrong. because nothing happens when i bypass switch or jump white wires from distribuer. it stays the same. and if i set it at 1 degree btdc, it runs crappy. it runs better at 16-20 degrees btdc. away from timing tab, where i cant get an excact degree. thats the only spot i can line-up distributer to where it runs like it should. is there somthing wrong with the distributer

[Pete104]

There is specific procedure to set the timing on this and many other engines. Don gave you the specs but your NOT reading the book. Are putting the engine in timing "prior" to starting it?

[potatoe]

yes, i try this when boat is running. i have read the steps from many different areas. and i watched a video on youtube for timing est ignition in a 3.0. mercruiser. they had started the boat, then why'll idling, they then jumped the distributer wires, and timed it 1 degree btdc. i could hear the motor change its tone when they did that. they also explained it. i have tried everything i could think of.

[Don S]

they then jumped the distributer wires, and timed it 1 degree btdc.

That is only half of what gets changed.
You missed the part on bypassing the shift interrupt switch

Here, read the instructions again.
I highlighted in yellow what you need to do.

[potatoe]

ive done that also. if you read from the very first thread that i put, you will see that switch was bypassed. i will try this process again , i hope i can figure this out for moday the 4th. thanks for all ,and any other info.

[Don S]

When you bypassed the shift interrupt switch, did you plug the wiring harness side of the connectors together?
Have run into posts where people have hooked the shift interrupt wires together which does nothing.

[potatoe]

yes, i understand. im pretty sure i plugged the right ones in coming out of harness. i guess i could plug the both ends into eachother to be sure, lol. if you could please look at this youtube video of est 3.0 mercruiser timing. its the only video of this subject on youtube that i can find. but he had a bypass switch that he plugged in with the 2 white wires connected together and the other black wire(on left of 2 white wires coming out of distributer)he hooked to 12v starter power. and that is when i heard the engine switch over to base mode. this wire looks like it runs up to that switch that i bypass over valve cover. could i try this to see if it will go to base mode? or will i hurt somthing? thanks again