Why not to buy Mercury

[liphunter]

In 2015, I bought a 2012 boat with a 2012 115 OPTIMAX.  So far so good. But I have to admit, after reading a few post, on a few forums, it has left me a little puckered. Nothing to do but enjoy the moment.

[fishinwrench]

@aarchdale,  Fuel pressure and air pressure (make sure they are within spec), then pinch the return lines and make sure the pressure spikes.    

After that (if all checks good) fire it up and do a "cylinder drop test" by removing one plug wire at a time.  What you are looking for is a cylinder that isn't carrying as much of a load as the others.

[aarchdale@coresleep.com]

On 4/19/2018 at 5:21 PM, fishinwrench said:

@aarchdale,  Fuel pressure and air pressure (make sure they are within spec), then pinch the return lines and make sure the pressure spikes.    

After that (if all checks good) fire it up and do a "cylinder drop test" by removing one plug wire at a time.  What you are looking for is a cylinder that isn't carrying as much of a load as the others.

Okay, got everything back together, couldnt do a pressure test because the tester i had only went to 100 PSI.  I had it running in the drive way on water and i pulled the top spark plug wire off and it died, pulled the middle off and it kept running smooth, bottom off and it died.  

Did a compression test and all three test at 115.  

What should i look at next? Injector maybe?

[Old plug]

We'll I sure did not add anything to it. You telling me I did.

On 4/19/2018 at 5:00 PM, fishinwrench said:

I catch enough flack from the stuff I say....I don't need anybody adding to it.

    

[fishinwrench]

1 minute ago, Old plug said:

We'll I sure did not add anything to it. You telling me I did.

    

Yeah you did!   You typed your reply into the Quote box.   It's ok though, I was able to decipher it.  

[fishinwrench]

3 hours ago, aarchdale@coresleep.com said:

Okay, got everything back together, couldnt do a pressure test because the tester i had only went to 100 PSI.  I had it running in the drive way on water and i pulled the top spark plug wire off and it died, pulled the middle off and it kept running smooth, bottom off and it died.  

Did a compression test and all three test at 115.  

What should i look at next? Injector maybe?

Which Opti are you running?  Not a V6?   Should be 90psi/fuel.....80psi/air.  No?  

If it's a 3 cylinder then I'll have to research it, I don't know off the top of my head.  

Have you taken a fuel sample from the VS to be sure there's no water in it?

[aarchdale@coresleep.com]

yep its the 1.5 3cylinder, my manual says 108 fuel, 94 air

[fishinwrench]

So basically it is running on #1 and #3. 

You have already verified good compression and good spark, so that leaves nothing to cause the loss of cylinder#2  but fuel and air.  

Either the spark plugs is bad, or the #2 fuel injector is either failing or is not being fired.   You can unplug the injector and fire it manually with a 9v transistor battery to see if it clicks, but to test the primary voltage to the injector requires a peak reading voltmeter (which you probably don't have).

The air injector is an unlikely culprit BUT there was a recall once upon a time on the black air injectors, the new ones that replaced them are blue. Personally I've never run across a bad air injector....just read about it.   My understanding is that a cylinder drop test done at idle will not show a problem with an air injector. But having never experienced one actually failing I'm not sure about that.   

A broken reed valve is a possibility, but that usually causes some noise (whistling/popping) that you would have noticed and mentioned.

[aarchdale@coresleep.com]

Ok, thanks, can i just swap the suspect injector with one that i know is working and fire it up to test?   I doubt its the reeds, i put Chris Carson reeds in it about 18 months ago

[ColdWaterFshr]

If I had money, I tell you what I'd do, I'd go downtown and buy a Mercury or two, I'm crazy 'bout a Mercury . . . .