Bad Tach? or Bad Connection

[sailsmanship]

Have an 89' Searay w/twin inboards. Runs fine, but starboard tach needle will rise about 1500 rpm every so often even when there has been no change in throttle position or condition. Bad tach,Bad connection, Bad ?

 

[jmccall001]

Re: Bad Tach? or Bad Connection

check your ground.

 

[paultek6]

Re: Bad Tach? or Bad Connection

if connections are good- you got tach goin bad this is the first signs before it stops workin altogether