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2010 Honda BF225 starts immediately but dies as soon as the rpm’s fall from the initial start.

A

Artcha

Member
Hi, I’m having an issue with my 2010 BF225 that I am hoping I can get some troubleshooting advice for.
When I start the motor cold the rpm’s jump up to over 1000 then normal fall back to 600ish a second later, on my port engine the rpm fall to 0 as the motor dies after initially catching.
The odd part is if I try and crank it again it will crank endlessly with no sign of life. If I turn the key off and on again it will repeat the same catch, rev up and immediately die. It did it about 5 times before it finally started last trip out.
Based on this I’m guessing it’s a fuel delivery issue and something with priming based on the key reset being needed for the engine to catch again, has anyone seen this? Would love a short list of things to look at once I’m back up on the boat this weekend and parts I may need. Once Running the engine performs identical to the starboard engine.
Any advice or thoughts would be greatly appreciated.
 
Just guessing here...

The first thing I would do is drain the VST into a clear bottle and see if any water or gunk settles out. If so, change or clean the low-pressure fuel filter. There is also the possibility that your high-pressure fuel filter has a problem. They go bad very quickly. Consider replacing it if you haven't done so recently.

Also, it is good practice to turn on the key, wait 3-4 seconds for the fuel system to pressurize, before cranking to start. That alone may help your issue.
 
Thanks much, I do let the engine sit with the ignition on for a few seconds before cranking, the VST drain is one I have on my list. How hard is it to replace either of those fuel filters with the boat in the water?
AC
 
I've not ever done any maintenance or repairs while boat is in the water. My fat fingers would be bound to drop something overboard. However, the LP fuel filter should be fairly easy. The HP filter would be very difficult - you need to remove the two small Philips-head screws holding the AIB diaphragm and move it aside, then remove the three bolts holding the HP fuel filter cover, to get to it. All of that is on the very back of the engine, and below the bracket holding the base for the engine cover.
 
And as I understand it the VST you can drain easily as long as you don't drop the tiny screw that controls the drain correct?
 
Yes. You don’t remove that screw, just loosen a bit and it will drain. On a motor that age, you might have a bit of difficulty turning the screw. Be careful not to strip the head…
 
Sounds good, thank you all.
Any other things to look for this weekend when I troubleshoot? I do have access to dr h but guessing that wouldn't help to identify what's happening unless it has detailed info around internal fuel pressure.
AC
 
If you've never change the HP fuel filter then it's definitely time to.
I believe it can cause all sorts of problems and I change mine every year just in case.
Once my boat goes on the water I'd like it to stay there for about 4 months!
And as CH says... There's not a lot you can do while the boat's on the water.
 
If this only happens at cold start, I wonder what temperature the engine "thinks" it is?

For example, if the engine coolant sensor is faulty, it might be reporting too high a temperature and causing the fuel system to be too lean at cold start.

If you can access the sensors or their connectors, you might be able to compare resistance readings between the two engines when cold.

But since you have Dr.H, I see no reason not to hook it up and compare some data like ect, map readings and tps.

The older manual trouble guude lists this symptom as a possible idle air control valve screen dirty or idle adjustment set too low. Not sure if that applies to your outboards though.

Good luck.
 
So I think it could be my main external fuel filters, or maybe bad gas? Although I would have thought both would impact top end not starting?
It happened to both engines when I went to go troubleshoot the problematic one.
Any ideas on what could impact both? I did install one of those check valves a few months ago on the fuel fill vent line, could it be having issues drawing out of the tank?
I’ll buy new external fuel filters anyways to install next trip up. Engines are idling just fibe, battery voltage was at 13.2… confused what else it could be that would affect both…
 
Fuel effects both, from the central fuel tank to both outboards. Bad fuel, water in it, clogged water separator fuel filter, water in the fuel. Try a portable fuel tank with new fuel on each, add a generous quantity of sea foam to the portable tank fuel.

You could have something bad that made it into your outboard fuel system filters.
 
Yeah I’m thinking similar, still confused why it’s only affecting the start up. Going to change filters tomorrow and look at the feasibility of using a spare tank, will add a few bottles of sea foam to the main tank as well.
 
You might also want to check your fuel line from the tank - if it (or the liner) is collapsing under load then that would affect both engines.
 
metal-chicken said:
You might also want to check your fuel line from the tank - if it (or the liner) is collapsing under load then that would affect both engines.
Click to expand...
I did an inspection of both lines (each engine has a draw point) and they look fine. Whats most intriguing to me is that they run fine once started, I would have thought bad gas would affect top end much more than starting.
 
There was some older gray fuel line that had problems with the plastic liner delaminating and clogging things up. I use the newer gray line, it is good stuff.
 
Yeah an external examination of the lines isn't always good enough as the liner can detach and collapse when fuel is pulled through.... But externally it looks fine.
 
Mercury fuel line is the worst I've ever used, causes so many issues when it gets older. I don't think this is your problem tho, as mentioned above, would cause issues under load. Just try turning key on and off three or four times allowing fuel system to prime, it could be an internal leak allowing a loss of fuel pressure when engine isn't running. Again, a fuel pressure test would illiminate the guess work.
 
I have the gauge ready to go, what I was thrown off by this weekend was it happening on both engines. I plan on replacing both external filters, using a bunch of fuel cleaner and seeing if it improves, if not I’ll do pressure tests and empty the vst.

Does Dr h give any useful stats like fuel pressure?
 
No, genearally if you don't have an alarm it won't tell you much. Just one thong to check. There is a second small dia wire to go to pos on the battery. Make sure it goes to the battery and not to the starter stud, very important because while cranking there is too much voltage drop for the efi system to function correctly. Also make sure your battery voltage isn't dropping below 10v during cranking. How old are these motors and how many hours?
 
11 years old, 1523 hours. I’ll check that wire, they have been serviced regularly so assuming they would catch that. On my n2k the voltage doesn’t drop below 12 during cranking.
 
Still trying to diagnose this one but have yet to haul it out so need to do that soon and look at the internal filters. Its still very odd its happening on both engines. Ive looked at all the hoses and they look fine, I've replaced the racor external filters as well. Using the hand pump/prime does not seem to make a difference. Will post again when I get the boat out of the water and can replace filters. My suspicion is I got bad gas and it messed something up however its odd the Racors looked fine.
 
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