Tach Issue

[Buddy Gold]

I am the new owner of this Cat 34 and it came equipped with a Sea Power 5 KW engine driven generator. It is running off of  a Universal 35 Diesel. It is great and I really like it except.  You can only use it when the engine is up to speed, which I get because the engine bogs down. That's acceptable to me. But the tach only runs when the Sea Power is engaged and then it reads incorrectly.  The previously owner made a correction chart verified with a piece of tape on the engine and a timing light but I want my tack to read correctly and I want it to read all the time.  Is this just not wired correctly?  I am loving this boat more and more everyday but this irks me.   Any suggestions? I see there is an adjustment screw on the back of the tack but that doesn't fix it operating on engine start up..  I know there are some really smart people on this forum and I have gained some great insight from reading other posts and I appreciate the people that give their time to help and hope someday I can contribute.

[Stu Jackson]

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But the tach only runs when the Sea Power is engaged and then it reads incorrectly.  The previously owner made a correction chart verified with a piece of tape on the engine and a timing light but I want my tack to read correctly and I want it to read all the time.  Is this just not wired correctly? 
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The tach will only run when the alternator, in your case generator, is operating.  This is because the tach is operated by an electrical signal from the alternator/generator.  Without the alt/gen regulator instructing the alt/gen to output, there will be no tach signal.  Universal engines do not have mechanical tach connections, unlike some others, perhaps Yanmars, that do, although many Yanmars use the alternator electrical tachs, too.

This is a new one on me.  Is the generator in place of an alternator?  Do you have an photos?

[Buddy Gold]

Yes, this replaced the alternator, I don't have a picture but here is the link.  https://www.meps.com/wp-content/uploads/2017/01/5.1kw6.3kw8kwseapower.pdf.

It is much larger so a build out was made into the head which restricts the door to the thru hulls so they had to be put on removal-able hinges.

So I guess I am down to adjusting my tach. If I have to pull that panel I would like to replace it with a new one or new decal as long as I have it out.  Any Idea on where to source one,.

[Ron Hill]

Buddy : Best to always let us know your hull# and production year, so we know a bit more about your C34.

I think your best bet on getting your engine tach to read what the engine is really doing -- is to call Teleflex (makers of you tach) Tel# 941-907-1000 X222 and let them know your problem.  They might be able to give you some dipswitch settings to gain an accurate tach read out!?!

A few thoughts

[Buddy Gold]

Good to know..Thanks

[KWKloeber]

Is this just not wired correctly? 

To answer that you'd need to provide how it's "current" ly wired and the wiring schematic for the gen.
How are you charging the batts from AC?

Hijra tach May be bad and need replacing.

You can design a custom panel online and they cut, label it, and it magically shows up on your doorstep. Or go with a stock say through Catalina Direct.

[Buddy Gold]

The number for telex has been disconnected and a internet search turns up nothing for them....????

[KWKloeber]

Teleflex was gobbled up by Seastar Solutions, who also gobbled up the likes of Sierra, shields hoses. etc.
http://www.seastarsolutions.com/

and now has gobbled up Seastar.
https://www.dometic.com/en-us/us

Dometic is at war with Marinco, who gobbled up about all the other remaining marine mfgrs. (ancor, pro mariner, bep, blue sea, etc.

There are guides how to set the dip switches but they are for 12v alts, not your gen -- maybe the gen mfgr can help?

[mark_53]

Since your gen doesn't kick in until RPMs are higher, have looked into another method of getting a signal to the tach?  I'm thinking there is a mechanical method to get tach data.

[KWKloeber]

Since your gen doesn't kick in until RPMs are higher, have looked into another method of getting a signal to the tach?  I'm thinking there is a mechanical method to get tach data.

There are, but the tach has to match the method/pickup.  Some newer tachs are capable of multiple inputs.

The alt AC signal (ours) is called a T input.  There are methods to count pulses by the injector pump, mechanical, and magnetic pickup (say a magnetic strip on the flywheel or crank pully.)

[Ron Hill]

Buddy : Just let me mention (my opinion) that a 5KW is a awful large generator for your boat!!  I mention that because I use a 1KW Honda to charge my batteries at anchor!! Some other C34s use a 2 KW Honda.  Both of those Hondas are more than enough to charge a 300 to 400 Amp hr. battery bank!!!!!

I'm wondering if your generator doesn't give a tach reading because it doesn't really "kick in" until the higher RPM's ??? 

A thought