do i have a bad tack??

[bolo78910]

when i turn my key switch of my tach stays the exact rpm it was at, if i tap the tach with a screwdriver handle, it fell below the 0 mark where it sopose to be with the keys off.

ok here is the pussel merc 1989 5.7 on a searay220 1990 with a 17 pitch my wot rpm is about 4000. 30 miles per

i go down to a 15 pitch and am only getting 4100 rpm at about 29 miles per ., with only me on board.


these speeds are with my gps,

coupler is new carb is kinda so so. but runs good after a good adjust.

i have the ac delco spark plugs in her but i have the auto type, should that makes a diffrent. will be intresting to hear the result on this one.

thanks

 

[Reel Poor]

Re: do i have a bad tack??

Are both props stainless or aluminum?
Are they the same brand?
Are they new?
Maybe the 15 has been repitched to about a 17 but not marked.

If the auto plugs are the same number with the exception of the M is missing, they are the same with the exception of the steel material, the auto plugs will rust away around the hex head and seat area. Especially if used in a saltwater enviroment.

 

[bolo78910]

Re: do i have a bad tack??

thanks they are both ss prop one is a 15x15 stellito and the other is a mercuiser 17. ok on the plugs i will change over to the marine. and to make it clear only those plugs on my boat is auto ok lol just to get that clear alt, starter, fuel pump. ect all marine. thanks for getting back

 

[searay3]

Re: do i have a bad tack??

Tachs do get fudged up with crap over time. If you can smack the gauge and it changes, replace it.