Tach install on 93 C40PLRR

[99yam40]

just looked a little harder and there were several 1993 40hp models that were 2 cylinder that all have the same lighting coil part #,
and the 3 cylinder models have a different lighting coil part #

[sea-nile]

Wow..Thanks guys....Now I dont feel so bad...Yea Im 2cyl 2 carbs...A mechanic I know that worked at the mariner plant told me he had the exact same motors on a couple different boats back in the day......He mentioned they didnt use a standard tach & needed a special tach because the signal came from under the flywheel if I'm remembering correctly....Thanks to both of you for hangin with me on this subject....I'm just guessing but my mind says theres probably 4 magnets under that flywheel????which would make it a 4 pole????

[boscoe99]

Two poles per magnet. One North. One South. Four magnets = 8 poles.


But I am not so certain that the pole setting on the tachometer has much correlation with the actual number of magnet poles.

[sea-nile]

LOL..at this stage of the ****...I guess I'll just try all of the setting & see what happens.....thanks again

[99yam40]

seems like something in the back of my mind is telling me pole and pulses were involved with these tach settings, but I am having a problem remembering what that is/was

[sea-nile]

from what I've gathered from different conversations about this..it does seem to be shrouded in mystery...even the faria guys were ify on what tack would work ...story of my life with this boat....I love the motor..its strong...my guy that worked at the mariner plant said mine was the fastest reving motor he'd seen...soooo.....guess I just keep pluging on n hope some majic solution presents itself....Thanks 99 for all ur input...truly appreciated man

[99yam40]

Wow..Thanks guys....Now I dont feel so bad...Yea Im 2cyl 2 carbs...A mechanic I know that worked at the mariner plant told me he had the exact same motors on a couple different boats back in the day...He mentioned they didnt use a standard tach & needed a special tach because the signal came from under the flywheel if I'm remembering correctly.......Thanks to both of you for hangin with me on this subject....I'm just guessing but my mind says theres probably 4 magnets under that flywheel????which would make it a 4 pole????

Most all older outboard motors used the pulses from the lighting coils to give RPM signals to a tach, so I am not sure what your friend was talking about.
some of the newer ones get a signal from the ECU, and the old car tachs used pulses from the points/coil.
run a wire just for testing from the tach to the motor to see if that gets it to work.
have you tried switching it back and forth as we mentioned?
my thoughts are if it was set to the wrong position, it would still read something, but not the correct RPM

[sea-nile]

HAHAHAHA lmao...Guys I (YOU) got it working....I finally got off my lazy ass n traced all the green wires back to the flywheel ...disconnected & wire brushed them.....found another green wire that was in the harness from the motor under the dash going to the key switch....that wire was plugged to a pigtail type setup...I plugged into that & jumpered to the battery...Fired it up an BAM....Tachs reading 1000 rpm...Usually takes a second or two for it to come down from high idle.plus I had it set high to begin with.....sooo...i think we're there.....Again..Let me thank both of you(99 & boscoe) for your help...Cuz I'm positive..without your input..i would NOT have been able to proceed from some kind of base line....You guys rock....Thanks sooo very much...I'm truly in your debt....Mike

[99yam40]

good to hear, but I am confused a little, what did you have the tach hooked into before?

pics are worth a thousand words

[sea-nile]

99yam..I was plugged into a green wire on a accessory pigtai[ that somebody had added with electrical tape....so I unhooked it at the key switch & & plugged the tach in there & it worked fine....Tried to upload pics buy it says file is to big...Im going to pull all that tape & see what that pigtail is all about....I'll get back to you once its unwraped

[sea-nile]

Alright gang...6 months later & $150 into it..believe I've discovered something i'm sure all parties concerned would be interested in hearing...(being that fanatic that doesn't take no for an answer..LOL)..I kept digging to find out what was actually happening...so wading thru a ton of vids on checking rpm with a different source( i.e. multi meter and using the formula provided to achieve said rpm's..(hz x 60 = rpm's} the #'s weren't adding up.untill i divided by 2..2400 at idle on multimeter & and; on setting 1 {farias chart says setting 4} on tach which read 1200 rpm's..i get 1180 on multi meter....ok im good i thought..take it pond to check wot..meter freezes up at 49 hz...shit....screw this...im buyin a inductive timing light an goin direct to the # 1 {top} spark plug....at idle its reading 2400 too...Wat the hell is going on....so i start googling yamis ignition system and bam..i see a post from this forum with boscoe, towns & 99 yam giving there input from back in 2016 i think....talk about wasted spark ignition.....i saw it on other blogs as well....heres why i couldnt let it go....at wot the tachs reading 6200 rpm with a solas 11.3 x 12 prop...i changed back to the prop that came with the motor..a 12.25 x 9 G series..{completely wore out pos Pontoon prop...4200 rpm....called faria AGAIN.. and get an old guy {service manager} & he says somethings not right..send it back and he'll put it on a freq meter & see if its not goin crazy at high rpm....and hed have to have to adjust the trim pot if it was.....waiting for its return now..shud be here nxt week sometime....this things giving me grey{er} hair..lol...but at least I think im starting to get to the truth of the mater...and thats all im concerned with..I think thats why the wrench that worked at the mariner factory said they needed a special tach....so guys....Comments??

[99yam40]

not much to say, just wait for the tach to show up and see how it works.
let us know what they say they did after checking out the tach

[sea-nile]

will do 99.....this has got me fascinated...cant wait to come to the end of it....my actron 7258 is picking up both signals/pulses...i.e. 2400 rpm..( when i know its 1200} .it can read to 9999 rpm...which means im only gona be able to see to 4500 rpm...gota call into actron now to see if theres a diode or filter of some kind to cancel 1 pulse...or...i find a timing light that reads 20,000 rpm....