2003 Honda BF 225 Rough Idle

[MARKTN]

My Honda BF 225 is idling rough. I just changed High and Low pressure fuel filters, Spark Plugs, and cleaned the IAC valve on top of the motor in efforts to fix the problem. I have had not issues at higher rpms until the other day i was running around 4500RPM when the engine lost power briefly twice and then has been fine with no other issues at higher RPMs. The engine did not shut off. I have had no lights coming on or alarms. I also put a new 02 sensor in last year bc the old one failed. I have not messed with the VST but thinking about taking it off and cleaning too. Any ideas would be appreciated. Engine has 485 hours on it.

[ROADRUNNER]

Could be old fuel line deteriorating from alcohol in the gasoline, or bad primer bulb. Would need to replace.

[MARKTN]

Never run ethonal gas in it. Have not changed primer bulb since it pumps up hard but good idea for a cheap fix i will give that a try.

[ROADRUNNER]

If you have not changed the bulb since 2003 that might be it. I have to change mine about every 7 years or so.

They say to use Mercury bulbs for the best results.

[MARKTN]

Update: Took it to the shop and they said it was fuel pump and pressure regulator. We will see if it fixes the problem.

[MARKTN]

He also said he figured it out by pinching the return line out of the fuel pump and it made the idle pickup and run smoothly. Just incase that helps anyone trouble shoot if they are having similar problems.

[Hickory Legend]

[ROADRUNNER]

Thanks! Good to know. Though, I hope I never have to find out on my engine,

[MARKTN]

I got my boat back and its still running kinda rough at idle. This motor is a used motor that i put as a repower on my stratos. The original motor was a johnson venom 200. Looking at the honda parts for the fuel tube and primer bulb it calls for 1/4" hose on one side of the bulb and 5/16" on the other ( not sure which side goes to the motor). I used the same fuel line and tube from tank off my johnson which is 3/8". Does anyone know if this matters? Below is the link to the parts diagram from honda. Im assuming that 6.5mm=1/4" and 7.5mm=5/16 for parts 8 and 7.
http://www.boats.net/parts/search/Ho...UBE/parts.html

[MARKTN]

What i mean to ask is does the 3/8" causing me issues instead of having the honda part.

[ROADRUNNER]

I was told to use a Mercury primer bulb I did and it works fine. There should be an arrow, pointing the flow direction of fuel to the engine on the bulb. Look carefully.

[HondaRay]

The fuel line size will not cause your engine to idle rough. Do you get an alarm when you idle for a short distance?? A faulty O2 sensor will cause a rough idle. BUT if you are still using the same fuel line and primer that came with your boat, it is certainly time for a change. Use a primer bulb of your choice but my number one choice (for vapor separation issues) is Yamaha.

[MARKTN]

I changed the 02 sensor last year and i am not getting an alarm now. You think the fuel line from the tank could be part of the problem as well? Not just the primer bulb. Thanks

[ROADRUNNER]

If your boat is an 2003 then you most likely do not have the alcohol resistant fuel line. The inside of the hose breaks down and can clog the fuel filters. This is caused by the ethanol in the gasoline. I need to do it to my boat, an 04. My friend has an 02 or 03 and it happened to him.

[MARKTN]

On the O2 sensor has anyone tried the automotive sensor instead of the honda marine one. They are the same engine as the honda odyssey motor. Also is there only one O2 sensor on the motor. I did find a chinese honda marine O2 sensor on ebay for 20 bucks.

[Team Hobbie Hut]

If your boat is an 2003 then you most likely do not have the alcohol resistant fuel line. The inside of the hose breaks down and can clog the fuel filters. This is caused by the ethanol in the gasoline. I need to do it to my boat, an 04. My friend has an 02 or 03 and it happened to him.

I had problems with the ethanol eating up the inside of the fuel line on my 2005. It was just the short piece of fuel line that ran from the primer bulb to the engine. The rest of the fuel line was ethanol resistant, but for some reason that short piece wasn't.

[MARKTN]

yeah i took my boat apart last night. It is a 96 stratos 201 pro with original fuel lines. Decided to go ahead and replace all the fuel lines while im in there and the anti siphon valves.

[MARKTN]

Does it matter what kind of fuel line you use as long as its ethanol safe? Can you get it at the local parts house? Or does it need to be marine.

[ROADRUNNER]

It should be Coast Guard approved BELOW DECK fuel hose, It is marine fuel SAE J1527 USCG Type A-1 ISO 7840-A1.

[HondaRay]

Any fuel line will work...at least for country boys!