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Bf250 hard starting cold

T

tsdean1980

New member
Hi all.
I have a new to me 2021 Honda bf250. It has approx 1000h on it .fully serviced and runs fine when going.

It takes a couple of key starts to fire up after it’s been sitting for a few hours or more or fresh in the morning. (I live in the tropics so it’s not cold )

If I go for a start shortly after it’s been running it starts perfectly.

Unsure where to start looking.
Previous owner had plugs done recently .
I’ll replace plugs anyhow I think to be sure.
I’ll pluck injectors next and have them done.

anyone come across this issue? Loss of rail pressure possibly?

Cheers
 
Hi,
I don't work on these but I suspect you could be on the mark with suspecting fuel rail pressure issue.

One thing to try might be to cycle the key to ON but don't crank the the starter. Wait a few seconds and do it again. Try doing that three or four times and see if it then cranks and starts easier when cold.

If it does then that might tell you that your hunch was right as doing that little exercise helps get the rail full of fuel.

If that's the case you're "simply" going to need to find out why it's not charging the the rail properly OR not keeping the rail full.
I put "simply" in quotation marks because it's probably not all that simple.

A good, basic thing to have is a mechanical fuel pressure gauge you can hook in to get an idea of what might be going on. On many outboards, it's easy to get a gauge but not often "simple" to plumb in. Well worth the effort for the information you can glean from testing though.

If doing that "key dance" doesn't make any difference, then you may be looking at a possible vacuum leak, sensor issue or maybe even a throttle body or IAC that's sticking or not working correctly. Cleaning those items can be tricky so great care should be taken if you decide to try doing that. Mishandling a throttle body or IAC can cause damage.

If at all possible for you it can be worth the bucks and trouble to get it to a dealer for the Dr.H diagnostics. This outboard should be well within warranty so maybe that can work out for you.

If you're going to do accurate troubleshooting on your own, you need accurate information. The real deal shop manual is the only thing I would trust for getting that info. You can order one here:

Honda Marine | Shop Manuals Publications | Honda Power Products Support Publications

publications.powerequipment.honda.com publications.powerequipment.honda.com

I'm sure I don't need to tell you that you need to be careful of the things that you do so as not to void your remaining warranty.

Best of luck and I hope you find a solution.
 
Check the fuel line downstream of the fuel pump for loose clamps, you could be sucking air. An indication of air entering the system downstream of the fuel filter will be tiny air bubbles in the fuel filter.
 
Thanks for all the replies . i appreciate your time.

The outboard doesnt have warrantly as previous owner serviced it themselves.

I have tried priming the fuel rail buy pre-ignitioning the key 4-5 times and it helped a little but not really noticable.

After using it today for few hours it seemed to idle bit rough and when loaded pre-planing speed shake a smidge.
so I think ill pull injectors and have them cleaned, then check coils/spark and rail pressure.

thanks all
 
Remove the idle air control valve body from the motor, there is a screen in there and it plugs up with carbon, where the IAC will not idle it up to help it start. Clean that screen and it should help with the starting issues
 
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