Honda BF30D outboard advice/ refresh/ sitting for 7 years

Hi folks, (first post)

I inherited a Gregor Angler 15 aluminum boat with a 2007 Honda BF30D from my dad. The entire package is in great shape and was stored indoors for the past 7 years untouched. Prior to that it was used 2-3 times per year. I would like to get this going again now that I have a pickup to pull it. I have been doing some research and I made a bit of a checklist to do before starting it up and I am hoping for some input to see if this all makes sense. Basically I am planning to change the engine oil/filter, gear case oil, spark plugs, impeller, new fuel, and then give it a go. Also I discovered Honda makes a garden hose adapter which I plan to get so I don't have to run water through ear muffs. I am not sure if my dad ran the carb dry before storing it or not.

Re the gear oil, the manual recommends SAE 90, however I have some leftover Redline 75-W140 that I recently used in my pickup diff., would that be OK to use? It does have some friction modifiers built in which I am not sure about for this application. Also I have read recommendations on this forum about adding a fuel/water separating filter - can that be installed in place of the existing fuel filter?

I have never worked on an outboard but I have done lots of auto maintenance and small projects in the past so I'm confident in figuring it out. Thanks for any helpful tips on this!

Hi S&W,

Well....let's hope your dad was meticulous and drained those carbs! If not, you're more than likely in for cleaning them and that can be either a BIG bill at a REPUTABLE shop or a daunting first time DIY experience. If you decide to do it yourself, consider buying the authorized Honda shop manual AND the Honda Marine Carburetion Manual. With those publications in hand and a good quality digital camera, you will be able to tackle that chore no problem.

I like your plan but I'm not greatly excited about "experimenting" with that diff lube. I don't think I'd do that myself. Just sayin'.

As far as the water separator goes....no, it's not to replace the on board fuel filter. Actually, I don't care for add on separators for smaller outboards because the volume of fuel you run each trip in a smaller vessel is comparatively so small that "component" isn't really necessary for trouble free operation. Also, if those things aren't regularly drained and properly maintained, as is often the case, they cause more issues than they alleviate. But, it's up to you if you want to make that commitment.

Don't use muffs! And, I would advise you not to mess with that built in leak....er....I mean...."flush" port. It looks great (untouched) and seems like a GREAT idea but it really isn't. Honda scrimped on the quality of that port valve and most of them that don't leak will usually begin to after being "disturbed" or utilized.

Instead of all that, get yourself a big, plastic trashcan and make yourself a proper
"test tank". It will require cutting a section out of the can to facilitate tipping the extension case in and out. And, you can fancy it up by gluing a plastic hose bib near the bottom for a drain/flow control and even connect a garden hose to direct drain water away from the work area. Make sure that you keep the water level a minimum of 5 inches above the cavitation plate and you will be able to get a THOROUGH engine cooling flush while assessing the operation of your pump and NO LEAK under the cover when you're done.

Your dad left you something that I really hope brings you and yours many happy, sunny days on the water!

Good luck and come back to share and ask questions.

Hey jgmo,

Thanks for your reply. I guess in retrospect the gear oil is short sided (why risk it for $10), there's just so many extras I have sitting around the garage that I would like to use up! But I will get the SAE 90..

I'm hoping I don't run into carb issues but I guess will just have to give it a shot to find out! I have learned on this forum and in the manual that the proper thing to do is run the carbs dry prior to storage but prior to that I have heard people talking about the seals drying out, but obviously that logic is for a different application, I was also thinking might as well replace any small fuel lines around the carb assuming that I discover it has been gummed up.

Also what you say about the water separator makes sense, I was thinking it was just some simple replacement filter. I like the idea of keeping it simple and just be proactive to make sure the boat is properly stored etc so I will scratch that.

Lastly, the tank is interesting. I like your idea I just hate to have to store more stuff (like huge modified trash cans) that I may only use every couple years. The flush port seems like a great idea but evidently poor design and execution. I need to research this more and I wonder if there isn't something I can smear on the threads of the plug to make it seal better or some kind of washer?

Thanks for talking me through this and the advice! I know this stuff is all pretty basic to the experienced boater! Once I get the boat to my house I will definitely upload some pics!

Well, if you do decide to use flush port and it leaks it is easy enough to take it apart and get it sealed up. The problem is that, even if you only run in fresh water, deposits form. Those deposits are usually the reason for the valve not to seal after being used in a flush. Taking it out and cleaning it will usually work to get it to seal again. No new parts necessary for the most part.


One thing your plan doesn't mention is the thermostat. You may not need to do anything there but I wanted to mention it because maintaining a properly functioning cooling system is SO important to longevity of these engines. The thermostat is as important as the waterpump to keep your outboard tip-top.

One last thing for EMPHASIS: Each carb has a drain screw. While disconnecting the fuel tank and idling the engine until it stalls is a good practice, it isn't enough to keep deposits from forming in those carburetors. Any time you aren't going to use the outboard for more than a couple of weeks, DRAIN THE CARBS. You will probably need to find THE screwdriver that reaches in and fits the screw head slots to make this easy. But taking the trouble to do this chore almost guarantees that when you pull the boat out to hit the water she fires right up and runs great!

Happy boating...under power....not just floating