Multimeter DVA peak voltage

[tjello327]

Hello forum,
I have a 500 volt multimeter that I purchased from Menards. It is just a standard $30 meter that will test ohms, AC & DC voltage & resistance. I need to test DVA peak voltage on my 125hp Force outboard and I have seen a DVA peak voltage adapter for sale. Will these adapters work on most standard multimeters?

Thanks

 

[john from md]

Re: Multimeter DVA peak voltage

It will work on the average digital multimeter. I'm not talking about the $2 from Harbor Freight, but one that has 20,000 ohms per volt capablity.

Why do you think you need a DVA meter?

John

 

[tjello327]

Re: Multimeter DVA peak voltage

Because I need to check the voltage out of my CDI boxes to be sure that my system is generating enough voltage before the coils. I did use a spark tester and all cylinders fire across a 1/2" gap, but #1 seems to skip very little once in a while. Even at idle when cold, the engine has a very slight miss once in a while. Runs great wide open and even mid rpm, but has a very slight miss sometimes at low rpm.

 

[john from md]

Re: Multimeter DVA peak voltage

I understand your thinking but, in the case of Force engines, it can cause problems.

The Force engines should never run smooth at idle. The reason for this is that they miss because it is running rich at idle. If it runs smooth at idle, then it is going to run too lean at WOT.

The Force carbs utilize the idle circuit in the mid range and WOT unlike some other engines. When the engine is adjusted properly, fuel build up at idle causes mild missing. However, at midrange and WOT, the engine will be running with a fuel mixture that will give max power and not burn a piston.

The reason for all this is that these engines were designed from the ground up for upper midrange and WOT operation. They were targeted for boats that were sold for skiing, wakeboarding and the like.

If you are getting good WOT rpm and speed, don't keep playing with it or you may wind up with a lean burning engine and that is not good.

John

 

[rodbolt]

Re: Multimeter DVA peak voltage

another missed maint item on the chysler and force multi cyl engines is periodic cleaning of the puddle drain screens.
sounds funny but thats what they called the fuel recirculation system.
its designed to move puddled,unburned, fuel from one cylinders intake to anothers combustion chamber.
if the check valves fail or the screen clogs it does funny things aat low speeds.

 

[tjello327]

Re: Multimeter DVA peak voltage

Thanks for the information, very helpful! I took my boat out the other day & it started fine, fast idle cold was o.k., but still had a mild roughness to it at about 1200 rpm. Once I throttle up beyond that point, it ran perfect. Cruise smooth at 25/30 mph, WOT at 4900 rpm & 38 mph.
I did take those bypass plates out and cleaned them out. I came the the realization that this is the nature of this engine.

 

[pnwboat]

Re: Multimeter DVA peak voltage

I have a 1988 125HP that I too notice around 1200 - 1500 RPM's the engine seems to run a tad rough. From 500 - 1100 RPM's it runs nice and smooth. From 1500 to 5600 RPM's it also runs smooth without any hesitation.

 

[john from md]

Re: Multimeter DVA peak voltage

Well guys, get used to the rough low speed. These carbs are as basic as you can get. The other issue is that you are using racing plugs. They don't like low rpm too much either.

John

 

[tjello327]

Re: Multimeter DVA peak voltage

Racing plugs? Is that because they are surface gap spark plugs? Do I have to use surface gap style in this engine?

 

[john from md]

Re: Multimeter DVA peak voltage

Yes, the surface gap plugs are racing plugs and you MUST use them. If you should use standard electrode plugs, your idle will get better but you will burn a hole in your pistons.

Regards,

John