Yet another tach wiring issue !!!

[Luckymann77]

Hey Guys,
First thread for me here and I need some help/moral support...

I have a 1977 1150 inline 6 on a 1983 Hydra Sport bass boat that's driving me crazy !!!

It was rebuilt about 4 years ago and I've had it 2 years.
Can't seem to get it to run right consistently at WOT...
Starts OK...
Mid throttle is OK...

But the holeshot isn't consistent...
Plan is to take her out tomorrow and open up the idle jet screws a bit to see if that helps...

Thanks to all that posted this tidbit of info elsewhere !!!

Also...and mainly for this discussion...but may be related.
I've been trying to get a tach to work on it to no avail...

My volt/ohm meter when set to 20 Vdc says it is getting a pulse of 6.8 to 7.4 Vdc from the yellow/red stripe wire off the
stator on one side of the stator wiring block but only 2.1 to 2.4 Vdc on the other yellow'red striped wire???

Not sure if this is correct setting for the meter...
or what to expect for readings either.

I've tried 2 different tachs...
both second hand and all settings on both...

Could really use some support here...

I'm near wits end and contemplating the need for a large hammer !!!

Thanks in advance,
(not feeling so lucky)
Luckymann77

 

[Chris1956]

Re: Yet another tach wiring issue !!!

First your running problem. Check the color of the spark plugs. If any are real clean, like new, you likely have water infiltration issues.

Did you measure stator voltage across the two yellow wires? You should see lots more AC voltage, especially if the rectifier is good. If the rectifier is open, you could see high AC voltage. If the rectifier is shorted to ground, it could pull voltage down.

The brown tach wire is connected to one of the yellow stator wires? It should be. Is it connected to the low stator reading? Maybe it has a short to ground.

 

[Luckymann77]

Re: Yet another tach wiring issue !!!

So I should measure across both yellow wires?

Not yellow to ground?

How much voltage is in the normal range?

Water infiltration means cracked block...right?
BAD !!!
Will check plugs...

Didn't get to take her out today...
Rained out AGAIN !!!
DADGUM weathermen can't get it right!!!

Thanks,
Luckymann77

 

[Chris1956]

Re: Yet another tach wiring issue !!!

Measure across both yellow wires. Voltage will vary, depending on condition of rectifier and battery. If rectifier is open (bad), voltage could be much higher. If rectifier is good, I would expect voltage to be a bit higher than battery voltage.

Water infiltration normally means bad crank seals or bad gasket on exhaust covers, exhaust covers or baffle have holes in them or some combo.

 

[Luckymann77]

Re: Yet another tach wiring issue !!!

OK...
Pulled the plugs and checked them out...
Can't get much of a read on them as they were new a couple months ago...
Did notice that #4 had some weird looking loose black speckle deposits on it that wiped right off...
#3 and #5 had some carbon arcing across the electrode...very small on both.

I must tell you that I have ran Sea Foam in the gas as well as sprayed her down with Sea Foam Carb fogger/cleaner as well last time out.
I have rebuilt the fuel pump this year also and replaced the fuel line from tank to motor with a new primer bulb.
I have started her up at night to look for arcing and found none.

The voltage between the yellow wires set at 20 VDC was 6.9 to 7.4 and on the 200 VAC setting was only 2.4 to 2.6 but not sure how that translates on this setting.
I checked for a short to ground on both yellow wires and found none.
This was done while everything was still hooked up...

Should I unhook the yellow wires and try these tests while they are not hooked up to the rectifier???
Is it OK to run the motor without these wires hooked up as usual???
BTW, the battery is new...Exide Marine Cranking Battery.

While I had the plugs out I did a compression check with my el cheapo Harbor Freight Tools tester and got these results...
#1...107
#2...130
#3...120
#4...125
#5...127
#6...120
Kinda concerned, obviously, of the #1 cylinder but not sure if it's a super bad issue.
Averages out to 121.5 and 85% is 103.28...
If that means anything...
Can anything be tried to raise the compression on #1???

Thanks for all your help !!!
Luckymann77

 

[Luckymann77]

Re: Yet another tach wiring issue !!!

:violin::violin:
:bump::bump:

:help::help: