PDA

View Full Version : Tach reading????


87MCProstar
07-17-2009, 12:10 PM
Hey guys since we've been on the lake a lot in the last two weeks since the boat is running everytime we turn the key!!! I noticed the rpm's are way off from what they should be, and I brought a gps up to the lake to verify what speed we are going. The boat tops out at around 46 mph but the tach is only reading like 3600. What would make that happen? Its a new tach hooked up by Mastercraft dealership, who finally got boat running.

TMCNo1
07-17-2009, 01:01 PM
Hey guys since we've been on the lake a lot in the last two weeks since the boat is running everytime we turn the key!!! I noticed the rpm's are way off from what they should be, and I brought a gps up to the lake to verify what speed we are going. The boat tops out at around 46 mph but the tach is only reading like 3600. What would make that happen? Its a new tach hooked up by Mastercraft dealership, who finally got boat running.

It could possibly be the way it is propped.

GuitsBoy
07-17-2009, 03:27 PM
I have the exact same problem, however perfect pass reads correctly, 4600 RPM at WOT. Id like to just replace the tach one of these days.

JimN
07-17-2009, 03:37 PM
Hey guys since we've been on the lake a lot in the last two weeks since the boat is running everytime we turn the key!!! I noticed the rpm's are way off from what they should be, and I brought a gps up to the lake to verify what speed we are going. The boat tops out at around 46 mph but the tach is only reading like 3600. What would make that happen? Its a new tach hooked up by Mastercraft dealership, who finally got boat running.

Make sure the distributor is grounded well and the area around it is clean, especially if the needle bounces a lot. If this has been addressed, have them check it- they installed the gauge, so it should have worked when you got it back.

Footin
07-17-2009, 03:50 PM
Is there a selector switch on the back for 4-6-8 cylinder?

IF there is and it is not selected for 8, it will throw the reading off.

JimN
07-17-2009, 04:28 PM
Is there a selector switch on the back for 4-6-8 cylinder?

IF there is and it is not selected for 8, it will throw the reading off.

If it's set to a lower number, it would read high, but it depends on the gauge.

87MCProstar
07-18-2009, 12:56 PM
the needle doesn't jump at all, i'll look at the ground. Its the Faria black Euro gauge from Ski Dim, if that helps at all