In addition to the items you plan to check before purchase, have them check the water pump impeller (and change it) and check the mid shaft bushing during that process. See below.
Also, pull the thermostats and check for corrosion at the seats and below the thermostat.
If you are having these engines checked by an authorized Honda shop, make sure that they hook up the Honda Diagnostic System (HDS) or Dr. H and get a full readout of performance parameters and any fault codes. Make sure that the seller addresses any fault codes.
And, of course, do an extended run on the water. Engines should start quickly and idle smoothly once warmed up. Idle rpm's should be right at 650. Engine should accelerate smoothly and maintain rpm's without hesitation. Do a sustained run at 4000 rpm's and see if it keeps a constant speed and rpm's. Do the same at 4600 rpm's.
The serial numbers will tell you whether or not you have the old style or new style exhaust tubes. If the old style, you may have problems with water getting high up into the exhaust tubes and blowing your HO2 sensor and possibly damaging the lower most cylinders. This is covered by Honda Service Bulletin # 56. If the engines do not have the new style exhaust tubes, then negotiate the price to have them installed. The parts are about $120 for each engine on boats.net, but the labor will likely be in the $400 to $500 range for each engine, assuming that the Tech has done it before and knows what they are doing. Several folks on this forum have done the job themselves, but you need to be pretty handy with some wrenches. SB #56 describes the entire change out procedure. Send an e-mail to me at
[email protected] and I will send you SB #56. That will let you determine whether or not you have the old exhaust tubes.
Somewhere around mid 2007, Honda changed the lower cowling to allow more water on to the mid shaft bushing. I doubt if you can tell whether you have the old cowling or the new one. So, whenever you change out the water pump (which should be every 200 hours or so if operating in saltwater or shallow water conditions) closely inspect the mid shaft bushing to make sure it is not deteriorated or loose in it's casing. If it goes bad, it can eat right through the lower cowling and mess up your drive shaft.
The very best thing you can do for these engines is to run them often. At 80 hours, your engines are not even properly broken in. They should be run at wide open throttle (WOT) as much as possible whenever it is safe to do so, over the next 100 hours or so. This will assure that the rings and valves are set properly. (Note: Not everyone agrees with this.)
If operating in saltwater, flush the engine with fresh water for at least 15 minutes after every use. DO NOT run the engines while flushing on the flush hose.
Attached is a list of issues with the BF 225 that I have garnered from the various forums, especially this one.
View attachment Honda Gripe List.pdf
The main thing needed to keep these engines healthy is good maintenance. Every 100 hours or at the end of every season...
* Change oil and filter
* Change lower unit oil
* Change HP and LP fuel filters
* If you have an external fuel/water separator (e.g. Racor), which you absolutely should have, change the filter element.
* Pull plugs and check for a good burn (milk chocolate brown) and apply light coat of grease to the threads before reinstalling.
* Grease throttle cables
* Pull prop and grease splines
* Grease all the zerk fittings
Be religious about maintenance.
Do not try to run these engines on muffs. They will quickly overheat. If you need to test them on land, remove the prop and test them in a barrel with constantly replenishing water.
