Max advanced spark timing, ridiculous procedure

[gazza2006au]

Can anyone think of a better way to do the max advanced timing on a mercury 50hp? the procedure is to be running the boat in the lake at wide open throttle 5200rpm flat out while sitting at the engine checking the timing with a timing light sounds absolutely stupid but its what mercury call for

i will be doing the water pump today than heading down to the river if anyone can think of a better way of doing it please let me know, i am the only one with a boat license to go over 10 knots so this is going to be difficult

[Gon Fishun]

Test wheel.jpgTest wheel is the way to go. Just back the trailer down, no need to unload boat.

[gazza2006au]

Now that's an idea but i don't trust the winch post to hold the boat back

[ericcs]

if you cant get a test wheel, back the motor into the water, start the motor with one of the plug leads removed. then, in gear rev it flat out using the timing light on plug 1. motor wont get anywhere near max RPM. only needs a few seconds to establish timing advance. I watched a marine mechanic do this many times.

[gazza2006au]

I now have another problem the very cluey bright spark that done the wiring used 2 black power cables i took these off the other day to clean i thought i kept them apart and just reversed the polarity now nothing works there is 1 main fuse on the engine that's ok and i am still getting spark, starter motor turns over when i jump it

does anyone know what i need to check or replace?

also not sure if the use the TDC pointer or the cutout that someone has created for TDC the max advance screw is almost screwed all the way in and its at 28 degrees that is what the manual calls for just the movable pointer and the cut out are both off by about 5mm of each other

[gazza2006au]

Figured i am going to do this properly so the next owner does not have this major shit fight on there hands, this is the state of the wiring its how i bought the boat red on black multiple times cannot figure out how someone would wire a engine in this configuration surely the cost of non marine and automotive power cables cost the same for black and red

i have worked out i blew the 3 solenoids, 1 starter solenoid and 2 tilt and trim solenoids plus one may power the whole boat just a bummer i should really have fixed the wiring before but i was itchin to get out and test the boat

i am going to use the extra long spark plug to find the true TDC of the engine and set my timing accordingly

[ranmar850]

Slip some red heat shrink over the black positive. That should he enough reminder, plenty of OEM stuff comes like that.

[scottar]

Geez Gazza, I've seen some dodgy stuff but that is wild.

[gazza2006au]

Ranmar the +-cables used were for the automotive industry the wiring is all black and corroded from salt water im going to replace both with red and black cables,new terminals and cable connections

Scottar ikr the last owner said he had bought the boat took it out once than sold it to me i think he had no clue at all about boats

[catshark]

fire extinguisher at the ready. looks like a long overdue repair.