no rpm reading on dash

[hydrasporter]

i recently purchased a used hydra-sports dv-ts with a johnson 150 gt vro ,its a 1990 model, im not getting an rpm reading on the dash at all, and was wondering where i should start troubleshooting this problem, the engine runs fine, just no rpm reading. any help would be greatly appreciated, thanks.

 

[bktheking]

Re: no rpm reading on dash

Check to see what voltage you are getting at the battery while its running, typically a blown rectifier/regulator will lead to nothing registering on the tach, check wiring to the rect/reg as well.

 

[psteurer]

Re: no rpm reading on dash

For that motor, the tach is likely connected to the remote control box. There is a plug in connector right below the key. Try pulling it out and putting it back in to clean the contacts. Also, take a look at the back of the tach and clean the wire terminals there. There is a a dial indicator on the back of the tach. Rotate it back and forth and put in in the same setting that you find it.

If that does not fix it and you have a volt ohm meter, set the meter to DC volts and check your battery after your engine has run. You should be seeing 13-14 DC volts or more. You can check it while the engine is running if you want.

 

[ezeke]

Re: no rpm reading on dash

In regards to the tachometer, it's possible for one side of the rectifier to work while the other does not, so check the rectifier as described here: http://forums.iboats.com/showpost.php?p=1289128&postcount=1

 

[hydrasporter]

Re: no rpm reading on dash

thanks for the info, ill check it and see, my voltmeter on the dash shows that its charging @about 14volts but ill check it at the battery to be sure, and also check my connections under the dash, ill let you know what i find.thanks

 

[hydrasporter]

Re: no rpm reading on dash

hey guys, i finally got a chance to hook up the hose to the motor and check the tach. i moved the dial on the back of the tach and put it back in its original position, no help, but after reading the thread on which wires to check from the rectifier (which looks brand new) i found that on the driver's side of the motor where the color coded power strip is, the screw holding the gray wire on was pretty loose, cleaned connection and tightened screw, problem solved. oh yeah i also found a bolt laying in the bottom of the cowling, it was a head bolt, hope everything is ok, i put it back in and tightened it up. i'll just keep my fingers crossed. thanks for the info everyone!

 

[kenmyfam]

Re: no rpm reading on dash

hey guys, i finally got a chance to hook up the hose to the motor and check the tach. i moved the dial on the back of the tach and put it back in its original position, no help, but after reading the thread on which wires to check from the rectifier (which looks brand new) i found that on the driver's side of the motor where the color coded power strip is, the screw holding the gray wire on was pretty loose, cleaned connection and tightened screw, problem solved. oh yeah i also found a bolt laying in the bottom of the cowling, it was a head bolt, hope everything is ok, i put it back in and tightened it up. i'll just keep my fingers crossed. thanks for the info everyone!

Time for a compression test.

 

[emdsapmgr]

Re: no rpm reading on dash

Was it actually a head bolt or a head cover bolt that came loose? If it was a head bolt, think I'd retorque them all-just in case.