mechanical advance questions

[KJM]

my engine started idling rough last week, anyway today i took the plate off the distributor and found that the mechanical advance was stuck with one weight out and one in. seems one of the pins that the weights revolve on came out of the hole it should be in. i had noticed that this pin came out easily about a month ago when i was trying to install electronic igniition. i wasn't sure if this was the way it should be or if its broke. i thought that the outside retainer that goes around the weights and everything might keep it all in place, guess not. anyway i'm wondering if you can buy and install a new mechanical advance mechanism and also what would be the result if i just left the advance mechanism off and maybe advanced the timing a little above the 6 degrees at idle that it calls for? any thoughts are appreciated. the engine is the merc 165 l6

 

[Maclin]

You need the mechanical advance to work correctly. Needs to be withdrawn by the springs when idling, then the weights swing out smoothly and be fully extended by 2500 rpm or so. You cannot make up for this with more initial advance. Too much initial and it will kick back when starting or worse. You may need to get a new distributor, or a donor that has the weight system intact and working freely.

 

[kenny nunez]

You will have to try and get a new or rebuilt distributor. There was no lower bushing in Delco distributors used on inline engines, and relied on a bushing in the block above the oil pump. This worked when the engines were new but caused a lot of poor running problems as the engines aged. The slop causes the dwell and timing to not hold steady. I have seen the fly weights almost cut the top off of a worn out Delco distributor. Mallory is the only distributor that I have seen that is a direct marine replacement. There may be others available on the internet.

 

[KJM]

i was afraid of that. so you cant buy the advance mechanism separately? right now i set the timing to about 12 or 14 and she starts fine and runs pretty good on the hose at higher rpms (a bit of missing) but i'm worried i'll do damage if i take her out on the water like that. what do you think? i'll look online for a replacement distributor.

 

[KJM]

is it possible to put a hei distributor on this engine?

 

[Bt Doctur]

It is possable to obtain auto dist from a junk yard and use the weights and springs, may be able to press out the bushing also

 

[KJM]

what bushing are you talking about? what is presumably broken on mine is the pin that the weight rotates on. is there some
kind of bushing that holds this in place?

 

[Bt Doctur]

the shaft bushing, I made new ones for mine from oillite bronze

 

[KJM]

i don't think the shaft bushing is gone. just the pin that holds the weight in place

 

[KJM]

these are the same pins the springs for the weights attach to

 

[kenny nunez]

It may be possible to rebuild your distributor from the parts of a 4 cylinder model. The shaft , springs and flyweights are the same. Your upper part that rubs the points needs to be reused . Then have bushings installed on the top and bottom of the housing. There is a good chance you may be able to obtain a rebuilt auto distributor which will have the bushing in the lower end then remove the vacuum advance and seal up the cavity where the vacuum advance was mounted. Your old distributor may have a small screen used as a flame arrestor mounted in the base of the housing which could be re used in the replacement unit by drilling the same size hole. Re use the original base plate and add a Petronics conversion.
HEI will fit, however it is not marine approved and the ignition feed circuit will have to be re wired and the shift interrupter may not work correctly.

 

[Scott Danforth]

is it possible to put a hei distributor on this engine?

NO No NO NO NO

that is an automotive distributor

it is posible to have your distributor repaired (cheap - just find an automotive machine shop with a sun distributor machine)
it is possible to find a used replacement marine distributor (ebay)
it is possible to fine a new replacement marine distributor

the old mallory marineYLM676AV or 9-26309 is now Sierra 18-5487

https://www.amazon.com/Sierra-International-18-5487-Conventional-Distributor/dp/B002MC2WFA

since sierra bought the rights to the marine distributors, the prices more than doubled.

https://www.summitracing.com/search...ch&SortOrder=Ascending&keyword=sierra 18-5487

however if you get the distributor as a kit with the coil, its cheaper
https://www.summitracing.com/parts/...bLXotRY1zQ_8u8f5yTKNbNBQJiHCmStwaAv6oEALw_wcB

because its called a V6 kit, yet the dizzy is a 18-5487

Converts 6 cyl. GM engines to electronic.

Contains:

• (1) 18-5435 Ignition Coil
• (1) 18-5487-2 Dist. Chev L6 Elec Ign
• (1) 18-8801-1 Spark Plug Wire Set

 

[KJM]

thanks for the info. scott those links are helpful buy way more money then i.m planning on spending on this. if the hei would work i,m not overly concerned about the marine vs auto difference. i'm usually by myself and i.ll take my chances on going boom! the hei distributors are less then $100 i'm just not sure one for an automotive l6 would fit a marine l6

 

[Scott Danforth]

two things with using an automotive dizzy

first, different loading so advance curve. Marine motors are mechanical advance only because they are always under load

here is the big one

automotive ignition systems in boats cause explosions

so if you value your life, use the proper marine electrical components

 

[KJM]

what if i just leave it with no advance and set a little ahead of whats specified? i'm no speed demon, just want to get fishing at a moderate speed.

 

[Scott Danforth]

take the dizzy to an experienced repair shop and have it corrected if you dont want to buy a new one.

however its your motor, if you want to kill it, have at it.

 

[KJM]

i think i'll try some jb weld to hold the pin in place. its not under much strain, just what the spring provides....