tach outta wack

[woodee148]

I was having some double clunks when I went into drive as well as the odd stall switching from forward to reverse and sometimes sticking in reverse. My local dealer suggested a water test and possibly a set up?? anyway out we went and one of the things that i had mentioned is that my tach at wot never went over 4500 so he climbed under the helm and started changing the dial on the back of the tach. He could not read the numbers so he just kept switching it as I read out the read until he felt it was right. Now it reads well over 5000rpm when I am only at 40 mph wheras I was getting 4500 RPM at 50 mph before. the only other thing taht has changed is i Installed smart tabs and i think they maybe set to low and are creating a bit of drage as I seem to have lost 10 mph overall at wot,
My question is how do I check to see if my tach is set up right and do you have any comments on my above information.

Its a 2007 5.0 merc

thanks

Woodee

 

[chiefalen]

Re: tach outta wack

The tach has 3 setting for 4cyl, 6 cyl, and 8 cyl. Yours should be for 8.

Good connection at the coil for the tach is required.

New boat still under warranty?

Take it back till they get the cable adjusted right. Check the out drive oil. Make them do it in front of you.

Hows the oil look?

That double clunking ain't good.

You do go from forward to neutral wait a few seconds and than into reverse?

Good luck!

 

[Don S]

Re: tach outta wack

There are no tachometer connections on the coil on that engine.
The signal comes from the ECM on the Gray/white wire.
There should be a gray/white wire with a female plin connectore on the engine for testing rpm, or you can use an inductive shop tach on a plug wire to get the correct rpm readings, or even have your dealer use a diagnostic scan tool, then set the tach to the proper setting and verify it's the same at idle and WOT rpms.
There are lots of things to cause low WOT rpms than just a bad tach, wrong prop, improperly trimmed, boat a lot heavier now than when you first got it. (Full of toys and stuff)

I was having some double clunks when I went into drive as well as the odd stall switching from forward to reverse and sometimes sticking in reverse.

Sounds more like you have some shift cable adjustment problems or a faulty lower shift cable (if you have an Alpha outdrive)

 

[chiefalen]

Re: tach outta wack

Don s is probably correct on the tach connection. Ether way new boat warranty don't touch a freekin thing let the guy get it right where you bought it.

You could actually void the warranty if you futz around in the motor. Some guys mark parts.

Some guy under the dash playing with the tach settings sounds fishy.While underway on the water.

 

[woodee148]

Re: tach outta wack

Thanks everyone, one of the problems I face is the dealer is 1.5 hrs away and I have difficulty giving up my boat for a week or two at a time in the short boating season of Ontario. I will take all of your advice once I bring the boat back in the fall before winterizing and have them try and address the issues then.
Woodee