Bouncing Tach
 

At higher rpm my tach starts bouncing. It's on the money and steady until about 4500 rpm. When I am trimmed out and running 5000 rpm it's all over the place. I replaced the tach and the new one does the same thing? :confused:

Looked for the obvious loose wire and found nothing. Could this be a sign of a bad ground?

Re: Bouncing Tach
 

Are you hitting the Rev limiter? My old Checkmate would bounce at wot when it was hitting the limiter?

Re: Bouncing Tach
 

Not hitting the limiter, checked it with a tach that clips around a spark plug wire and I was right at 4950-5000 rpm when trimmed out. It starts at about 4500 and gets worse as the rpms increase. Under 4500 it's steady and accurate. :confused:

Re: Bouncing Tach
 

CHECK THE DIST CAP A BAD CAP WILL CAUSE TACH TO JUMP

JOE
AMERICAN PERFORMANCE MARINE
410-573-0057
[email protected]

Re: Bouncing Tach
 

Okay, now I'm gonna sound stupid but I don't think my motor even has a distributor?

It's a 2003 Volvo Penta 5.7 GXi

Re: Bouncing Tach
 

Mine does the same. Merc 575SCi
replaced cap & rotor same problem.

Still looking for a cure too

Re: Bouncing Tach
 

Mine was doing that last weekend. Spent about an hour touching every connection and trying to move every wire. I didnt find the loose groung I was looking for but when I ran the boat this weekend it was dead on. one of the plugs on the wiring harness must have been loose.

Re: Bouncing Tach
 

same problem on my playboy

Re: Bouncing Tach
 

"prongs of the cannonball plug"

you mean the doohicky in the whatcha-ma-thing?

laymans terms please... or ill just tell my boat wrench-a-thingy guy :cool:

Re: Bouncing Tach
 

I had the problem and the electricals shut my motor down. Ended up re-wiring the port side ignition and something near the distributor