Tach problem on 90spl put a new tach on and it sits at 6000 rpm

[toddschubert]

J90TSLECM Johnny Old tack with lights was broken arm and reading erratic. Put a working used one of exact type and it worked for a couple of hours then went to reading high at some point. It is resting at 6000 and reacts to engine rpm a little bit say to 6500. Lights work and it jumps just a little when ignition turned on as expected but won't reset to 0 when turned off. Just sitting at 6000 idle and 6500 running

Any idea on what could be going on here and what to look for?

 

[SparkieBoat]

maybe a bad rectifier, troubleshooting guide in my sig below

 

[toddschubert]

Back to this problem.
I changed the rectifier (rectifier only no regulator) and still have the same problem. I got ripped off too and paid $55 for the thing. I tested the old one w dvm and saw readings that indicated it was bad but new one reads same way. on closer inspection it appears good along w new one.
Any other suggestions on why my tach is not working? I'm getting about 40V dc off the engine which I'm guessing is OK. What else to look for?

 

[boobie]

Are you getting the 40 volts D.C. off of the gray wire ?? Tachs hate D.C. voltage.

 

[SparkieBoat]

If your rectifier is DVA tested good and your stator test good and your power pack is good and then I would start checking all my wires and connections. I have seen bad rectifiers right out the box. I am pretty sure the CDI makes one with a regulator added in. If you ever replace your stator go with the higher amp one.

 

[V153]

Do you have the replacement tach dialed to the correct pole setting?

 

[V153]

Should zero when ya key the ignition on.

 

[toddschubert]

Should zero when ya key the ignition on.

does not zero thats why i think new tach is now damaged

 

[toddschubert]

40 V is on main batt charge cable. I'll have to go check the grey

 

[toddschubert]

Do you have the replacement tach dialed to the correct pole setting?

I tried em both/all