2005 225 4 stroke struggling to get on plane

Just purchased motor in March. Boat and motor was sitting since 2011. Test drive went great, boat got up on plane and reached 65 mph. Went to mechanic for check and everything came back fine, only 157 hours on it! Had tune up, change oil, filters, ect.. First couple of times out ran perfect. We put seafoam in tanks immediately after purchased it. Took out last week and had to switch tanks and boat began to idle rough and struggle to get to plane and when we did only made it to 48 mph. Immediately put fuel injector cleaner in engine and picked up a litte speed, 54 mph. Took home and emptied tanks and found some water, emptied water seperator and checked plugs and they were fine. Took it back out and still very sluggish even after putting more fuel injector cleaner in it. Need help! Heading to Canada a week from today.

Stop with the cleaners. They will damage the pre filters on the injectors. You need to replace the High pressure fuel filter on the VST.

Thank you! Will get it done tomorrow.

Also check for any spin on water separating fuel filter between the motor and the tank. May look like a spin on oil filter. If a Honda filter was installed, it would have a clear bowl at the bottom. Being a bass boat, there is limited space and if enclosed, it should have been a spin on filter. Depending on who rigged it originally, there may not be any.

You should probably replace the low pressure filter too.

Either the low or high pressure filters could have gotten contaminated by debris or water in the second tank.

Make sure that the fuel valve that switches between tanks is fully operated. You may want to work it back and forth a few times, if you have not already done so. Could be some crude in the valve that is partially blocking fuel flow.

Mike

Thanks to Mike and Chris we changed both the high and low pressure filter. The high pressure filter was black, the low pressure filter wasn't bad but still replaced. We checked the water seperator and it had some sentiment in it. We cleaned it it out, drained the fuel until we had clean fuel and then took it out on the river between rain showers for about 20 minutes. It ran better but still doesn't have that get up and go. One thing we did notice was when in neutral it was smooth but when putting it in gear it got rough.

When you were into the HP filter, did you pull the VST and drain/clean thoroughly? That needs to be done. Also, there is a needle valve on a float in there that you need to make sure is clean and operating correctly. If that all checks out, then Chris' initial take, dealing with the injectors, is where you probably will need to go next. Bad gas can screw up a lot of things on an 4-stroke outboard.

Thanks and yes we did. I just watched a video on replacing the injectors in a yamaha 4 stroke and it didn't look too hard but couldn't find any for the honda. Is changing the injectors something I can do?

Run it on a portable tank of known, good fuel. You might be chasing your tail when it's a simple fix ...

nkyfan said:

Thanks and yes we did. I just watched a video on replacing the injectors in a yamaha 4 stroke and it didn't look too hard but couldn't find any for the honda. Is changing the injectors something I can do?

Click to expand...

You can absolutely do this.

Clean the VST and pull the injectors, No need to replace them, just have them serviced.