Correct me if this is the wrong forum for this.

 

Problems:

 

1. Start the day (45 degrees) and the rpms go up to 6k+ at slow speeds.  After a while(warming up and placing it in forward, neutral, reverse, etc) it seems to correct itself.

 

2.  End of the day (55 degrees and raining) started driving back, the motor would only get up to 10 mph, no get on plane with pedal fully down.  Almost felt like it was flooded, but would stay the same rpms and speed, not bog down more.  I stopped for 10 minutes, tried again and it worked fine

 

Where would you start?

 

I replaced spark plugs, fuel filter. 

 

- Should I drain gas to use in lawn mower and try that first? 

- Should I wrap the priming bulb to make sure it isn't leaking?

 

Thanks in advance.

Not trying squash your ambitions but unless you are a competent mechanic there's probably not a whole lot you are going to be able to do yourself.  It sounds like something causing the ECM to go haywire, possibly the TPS causing it to rev up like it did.  It sounds like when you started off and it would only go 10mph it was in a limp home mode, there are a couple things that can cause this.   I'm pretty sure you are going to need the computer interface to diagnose the problem. 

 

Now, if you have the skills and equipment, because there's not much use in trying it yourself without both, you can go over to Scream and Fly  http://www.screamandfly.com/forumdisplay.php?20-Technical-Discussion  and just about every Mercury guru in the country is on that site.

Decent mechanic, just need advice as to what it could be from those that have experience with these engines.  Next time, I am going to buy the most bulletproof motor out there (if there is one).

There is no such thing. You have two options for that, buy a new motor and sell or trade it in for another new one before the 100% coverage warrantee runs out, or hope you are one of the lucky ones when you buy a used one because there's not a make or model out there that's not going to have a certain percent of failures. Now, you have to do your homework because some have a much higher percentage than others, but they all break.

As for what you have right now, you need to see which ECM you have and see if the guys on S&F can tell you what you need for diagnostics software and cable, or if it takes a special hand set. I'm pretty good with the JohnnyRudes but haven't done much with Merc's since the early 70's.

Somebody might be able to give you an idea but without the software and being able to look at the ECM and possible fault codes (if that model has them) anything you do would be strictly a guess, and guessed parts can get very expensive. You will need to give them the ECM number and year model of the motor.

These things are not different than your computerized cars now, it takes a computer to check the computer to see what's going on.

Also understand, if you plan of keeping the motor for a long time yet, and you think you can work on it, you had just as well spend the bucks for the diagnostics software because this is probably not going to be the only time you will need it.

I was just doing some searching and you might have a problem. Diagnostics software ain't readily available, seems Merc only sells it to dealers. CDI seems to have a version they sell, but not sure it's for the straight EFI motors, or even if there is any for the EFI's. I know DFI motors like Opti-Pops and Verado's have it.