There you go again CHawk_man.....making SENSE....as usual:~)
I believe that the Dr. H tool would be what is referred to as "backward compatible". Meaning it should work as well with the older engines as it does with the newer ones. As long as the tool comes supplied with the appropriate connectors, the data retrieval should be pretty much the same. But...it is an excellent question to ask of ANY supplier you may want to buy from.
I think the diagnostic tool COULD be considered something REASONABLE to have for the individual outboard owner IF you have a good understanding of the internal combustion engine and a basic understanding of "automotive" (12volts) electrical systems related to electronic fuel injection.
I qualify it that way because many people will buy one of these thinking it is a "magic box". Something that, once you've shelled out the cash, will give you "all the answers". Well...it just doesn't work that way. It's really just another tool when it comes right down to it and there are MANY folks out there that own their own scanner but STILL can't figure out why their engine doesn't run correctly because they don't have the background or training to properly interpret what the scan tool may reveal.
Also, the professional will probably use this tool AT LEAST once a day...while most of us will buy it... MAYBE use it once....and then put it in a drawer for a long time. That's actually what we WANT to happen! If we needed it all the time....that would mean our engine is constantly giving us problems!
Having said all that though...it is a statistical fact that diagnostic time is THE #1 area of cost associated with taking your EFI engine to a repair shop IF it has a running issue. And, with the prices I'm seeing for some of these tools.....it may be that the thing could almost pay for itself the first time you needed it. That is...IF you REALLY needed it.
As CHawk_man points out....JUST the ability to retrieve the codes and then being able to interpret what they may be telling you will, MOST of the time, get you close ENOUGH.
And I would say having that HELM Inc. shop manual is the FIRST purchase any DIYER should make. That is a TOOL too....and...just beneath your BRAIN...I would consider it the most ESSENTIAL tool you could own.
Because, the manual will tell you HOW to do many things that the scan tool will not. How to check fuel pressure...fuel volume....how to clean and replace the VST and fuel pump.
The THERMOSTATS have a GREAT deal to do with engine performance but they won't be listed on the scan tool menu. They ARE in the shop manual. And the list goes on...timing....valve lash....crankshaft thrust....all things part of having your "ducks in a row" when sorting out a "runability" issue or for just keeping an eye out on how things are wearing.
But there is CERTAINLY a good argument to be made that having the ability of plugging in and seeing, in real time, what your ECM is seeing and doing could be almost priceless at times. Being able to see what the sensors are reporting...if they are in range or not...what the computer is commanding...fuel injector pulse widths....IAC percentages....and inputs...rpms...TPS signal...O2 switching....all right there in front of you....
....is obviously pretty valuable.
Owning your own scan tool would give you the ability to build a data base on your properly running engines so that you know what's a"normal" value for a given component or operating condition should you choose to use it to become more familiar with how your outboards operate. This will make troubleshooting even easier when the need arises.
So...it boils down to....what do you ALREADY know? How much do you WANT to know?....and, maybe.....how much do you want to LEARN?
Aside from those considerations would be the cost. You have to do a bit of self assessment to answer the above questions and then square them with any budget you may be working with.
And then....there's me.
I'd like to own one just to play around with it!
