What could be wrong???...HELP...1993 115hp VRO

[chads30]

Have a 1993 Evinrude 115hp VRO.
Was out on the boat all day and coming home into a headwind with pretty big swells and bouncing everywhere.
5 min from home it just cut back to 3200rpm out of no where.
It usually runs at 5000rpm or more and it was before it cut back.
I put in a new fuel filter, dry gas, a new gas bulb, checked the compression, plugs, etc.
Then i tried taking it out again and it didnt fix a thing. It just sounds throatier and deeper for some reason.
Could the VRO system have failed? How do I check that without the obvious thing of taking it out for a 4 hour drive and seeing if the oil does go down?
I don't wanna burn it up.
Thanks in advance guys!

 

[Joe Reeves]

Re: What could be wrong???...HELP...1993 115hp VRO

Start with the basics.

What is the compression readings of all the cylinders by cylinder number?

With the spark plugs removed, do you have spark that will jump a 7/16" gap on all cylinders?

With the carburetor face plate removed and the engine running, is any gas being blown back out of any of the carburetor throats?

 

[chads30]

Re: What could be wrong???...HELP...1993 115hp VRO

The compression is right around 100 on all four.
The spark is good.

 

[karlow1]

Re: What could be wrong???...HELP...1993 115hp VRO

Did you lose a cylinder? bad plug, did a wire fall off?
Does it idle the same at the same speed?

 

[Chris1956]

Re: What could be wrong???...HELP...1993 115hp VRO

You likely would have seized the motor if the VRO was bad. You can always run a 50::1 premix in the fuel tank. It will not hurt the motor if the VRO works or not, that way.
If you accelerate the motor up from idle, does it stop at 3300 RPM at the normal spot, or does it just gradually build such that in order to get to 3300 RPM you need to be at WOT?

Is there any way you can check the cylinders spark at full RPM?

 

[chads30]

Re: What could be wrong???...HELP...1993 115hp VRO

Im pretty sure it just gets to 3300rpm at WOT and it sounds a little deeper