99' Capri 1750 tachometer / fuel gauge issues

[jkm2730]

Just got my new, to me, boat out today and noticed the following things:<br /><br />The tachometer jumps around. Its not dead and sometimes I think it pretty close to correct but it would sometimes be between 5k and 6k when we were just doing 5-10mph. Sometimes I could toggle the bilge pump on and off and the tach would partially or mostly recover and then work for a while but never 100% of the time.<br /><br />The fuel gauge worked fine when we were filling up the tank as I watched it go from 1/4 to 3/4 during our stop at the gas station. While under way the fuel gauge just continued to jump between maxed out and 3/4 or as the fuel level started going down it would jump between 1/2 and full. Now while sitting in the driveway the fuel gauge reads solid between 1/2 and 3/4.<br /><br />All of the other gauges seem to operate good and appear stable during operation.<br /><br />Any ideas?<br /><br />thanx,<br />jeff

 

[SpinnerBait_Nut]

Re: 99' Capri 1750 tachometer / fuel gauge issues

Boat Questions and Topics (non engine topics)<br />Welcome to iboats.

 

[Mischief Managed]

Re: 99' Capri 1750 tachometer / fuel gauge issues

Should be a switch on the back of the tachometer that allows it to be used with a 4, 6 or 8 cylinder engine. Often, moving the switch back and forth a few times will clean the conatcts and restore normal operation. <br /><br />The fuel level sending unit has no damping whatsoever. It'll tend to jump all over the place as the fuel sloshes around while the boat is moving. The problem is worse on smaller boats. Just use the gauge as a guideline for refueling until you can figure out it's accuracy. They are rarely accurate.<br /><br />In theory, a decent sized capacitor accross the fuel sending unit lead and "ground" (-12V) will damp the movement of the fuel gauge. I meant to do this on my old boat and never got around to it. My new boat is bigger and does not have the bouncy needle problem. A capacitor will not make it any more or less accurate though.