# Yamaha F225 4 stroke problems



## Woody45 (Apr 30, 2008)

I recently changed my fuel/water seperator and the fuel filter on the engine as well as put new plugs in and the engine RPM's will not go over 4000 RPM, if I push the throttle up to max it just bogs down and loses power. I had to put a new lower unit on when I went to change the water pump and had my prop reworked, other than that no other maintenance has been done. HELP !


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## chad403 (Apr 20, 2008)

Sounds like a fuel issue. Check your fuel/water separator again. You might have picked up a lot water and is straining for fuel. Your fuel filter within the vapor separator may be plugged. But first and check if your getting plenty of fuel from the tank. If all this is clear, compression test.


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## Woody45 (Apr 30, 2008)

*Vapor seperator ?*

Thanks for the quick response chad403, where is the vapor seperator located ?


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## chad403 (Apr 20, 2008)

Within the fuel tank on the side of the motor.


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## lastcast (Oct 12, 2007)

Another thing that can drive you crazy are weak/deteriorating fuel lines from ethanol.


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## Evensplit (Oct 2, 2007)

+1 for fuel related. Check your tank vent too. A restricted vent line will make them bog down.


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## purple haze (Sep 2, 2013)

That some good advise about checking the filter in the VST. Just before you open the VST pull the fuel drain plug on the lower side. When you drain the fuel take a sample of it in a small glass jar. If there is trash that has settle in the tank it will drain out. Then you will want to pull the upper half and clean the filter that is attach to the bottom of the electric fuel pump. I had this same problem on a set of 225 in the past.


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## markw4321 (Oct 4, 2007)

Injectors may be clogged as well. If cleaning the vst doesn't fix it look to your injectors. Napa auto parts around car city can clean your injectors if you need it done.


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## Woody45 (Apr 30, 2008)

Does the exhaust need to be removed to get to the VST ?


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## Xpac (Jun 22, 2011)

What type of fuel line are you using? I had a new line collapse last year and it behaved the same way you described. It was the line between the bulb and engine. Usually if the bulb is flat while running, you have an obstruction in the line between the bulb and tank. If there's a clog after the bulb then you cant tell unless you remove the lines and inspect them. If it turns out to be a fuel line problem, this stuff is really good:
http://www.tridentmarine.com/stage/documents/365A1-15FUELHOSESpecificationSheet.pdf


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## Sequoiha (Sep 28, 2007)

When you get tired of trying to fix it, bring it to me and let me fix it for you.. It is apparent you are in over your head, not trying to be mean, but these are tough ones. The intake has to come off to get to the vst.


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## Sequoiha (Sep 28, 2007)

I also have a fuel injector cleaning machine,


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## hjorgan (Sep 30, 2007)

Had a similar problem, eventually got a portable gas tank direct to the motor to eliminate motor issues. Turned out to be a pinhole leak in the fuel line under the deck.

Eliminated the motor anyway.


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## Woody45 (Apr 30, 2008)

Update : After speaking with a few different people, it was decided on that my propeller was the culprit, and not a fuel problem. I had my SS prop overhauled and asked them to put a little more cup in the blades to give me more performance on the top end. I guess they put too much cup in it and it was cavitating? I put a new aluminum prop on this weekend and I magically get up to 5000-5200rpm WOT. Thanks for all the help guys !


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## Sequoiha (Sep 28, 2007)

Glad you got it fixed, having your prop re pitched sure would have been some good info on the original post. I know you said reworked, could have saved you a lot of time.


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## X-Shark (Oct 3, 2007)

I actually thought about that on the original post. You did a whole bunch of changes real quick and the problem magically appeared.


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## Woody45 (Apr 30, 2008)

X-Shark, that was my ADD in full effect. I shotgunned it to get everything fixed at once. Next time maybe I will do one thing at a time to alleviate this self-induced headache.


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