Engine trouble with 98 Vmax 150.

[Tom 1]

I have a VMAX 150 that has problems with the fuel system or just fuel itself. The motor would run fine at the beginning of season after being winterized then go down hill after using it. The motor seems to hesitate and have no power(hp) and to seems bogged down. I changed the plugs, cleaned fuel filter with solvent as suggested in manual and had a local mechanic install separator. I also replaced the plugs and ran it today. Today it ran better than tourney Friday but still not 100% and hole shot takes longer to get on plane than it normally does. The motor is on a 17'6" Skeeter which usually screams when you drop the hammer. When I drop the hammer now it bogs down. I haven't added any fuel additives yet. It seems like bad fuel eventhough I drained the entire 30 gallon tank and put in fresh this year. Any suggestions before I accidentally hit bridge motor first. I live in Mass so we have 10% Ethanol in our fuel. Any help greatly appreciated.

[BuzzB8]

Sounds like it may need some fuel pump replacements or fuel line and primer bulb.

[Hamfisted]

What color is the actual filter element under the hood? If its brown change it, it should be yellow. Can you pump the primer ball up firm with the motor off? If not check your fuel pumps. You can't really clean those filter elements, you should just install a new one. Its not worth the hassle. Empty out the Racor and (refill) pour in a can of Berryman's Chemtool cleaner (Walmart...), and run that through the motor too. That'll clean out the carbs. Ethanol does attract moisture, so use Sta-Bil and Sea Foam in your fuel tank on a regular basis. Ethanol is also 25% less productive than straight gas. But the small 10% that they are blending in should not hurt your power output too much. But if you ran straight Ethanol you'd have to rejet the carbs.

-Mike

[Tom 1]

The primer bulb seems fine when running and pumps up firm when off. I don't know about the pumps that may be too much for me to get into but thanks for the advice. I just took the fuel sender out of my tank and noticed the gasket is worn. This maybe how the water is getting in my fuel. I just ordered a replacement gasket 2 weeks to arrive.

[Tom 1]

I will replace the element and the primer ball seems fine. I will have my mechanic look at the fuel pump. I'll also try the other suggestions. thanks for the advice going out to work on it now.

[1PairOfChoppers]

If after fresh fuel it still bogs down, I would suspect the fuel pumps. You've already done the below with no change in performance.

Plugs
Primer Bulb
Fresh Gas
Checked Fuel Filter

I did all of the above to mine 150 ox66 before I figured out it was my fuel pumps. One day burning WOT accross the lake it all but quit to an idle then would run WOT when it wanted to. Runs like new with the new fuel pumps.

Has is it rained hard on your boat since draining and putting new gas in? If not, how does enough water get under in the fuel sending unit gasket to cause problems. If there is enough water to cause performance issues, I would expect the red ring in the fuel filter to be floating. I'm not familiar with Skeeter boats but I would think this is in and enclosed area.

If you are a little mechanically inclined, you should be able to install new fuel pumps yourself.

You can find info on parts here:
http://www.yamaha-motor.com/ou....aspx

or buy them here:
http://www.boats.net/parts/sea....html

If your engine model number is 150TLRW (1998 Outboard) the Fuel Pump Assy part number is 6E5-24410-03-00.

This info is based on my experience and would listen to hamfisted before me.
He knows his stuff.

Good luck!





Modified by 1PairOfChoppers at 12:41 PM 5/23/2007

[Tom 1]

I just drained tank and will be refilling a couple of gallons to see if problem is corrected. I have a Moeller Marine 30 gallon gas tank where the sender is mounted to the tank through a 1-1.5 inch hole in tank. There are five screws that hold it down between the round metal plate of the sender and the rubber gasket. I get water sometimes when I slowdown too fast and water washes over the back of the boat or heavy rain may drip off back hatch onto tank. Area where the sender is mounted to the tank has a depression from when they drilled the screws to mount tank or when they pressed hole through tank for sender. I notice there is a puddle around this area. I will attempt to take pictures of same and post but I have to wait for my wife's camera. I will replace fuel pumps next as I belive I located them. I bought the boat about four years ago and never had any issues until last year at end of season and now. I apppreciate all the help as this is a first trying to fix an outboard.

[Tom 1]

I ran it with fresh fuel after also draining bottoms of carburetors and the engine ran perfect. I guess I have to either replace tank or fix gasket issue. Thanks again for the help. I ordered two fuel pumps to replace anyways I think it's time.

[BuzzB8]

You better hold on tight once you get it all fixed! It's gonna fly.

[1PairOfChoppers]

For what it's worth, when I replaced my pumps, the dealer where I bought the pumps at mentioned they normally last 5-6 years.

[Tom 1]

1pair of choppers the model number I copied of of motor is P150TLRX IS THAT THE SAME AS P150TLRW THAT I SEE ON THE YAMAHA PARTS PAGE YOU DIRECTED ME TOO. ALSO WHILE LOOKING AT THE MOTOR I OBSERVED THE SPARKPLUG SIZE AS BR7HS-10. I HAVE BR8HS-10 IN THE MOTOR BECAUSE THATS WHAT CAME WITH IT AND I HAVE NOT CHANGED THE TYPE R NUMBER OF THE PLUG. WHAT SORT OF PROBLEMS DO YOU THINK I HAVE CREATED WITH THE WRONG PLUG. I FEEL LIKE A COMPLETE IDIOT WITH THE WRONG PLUGS HOW SIMPLE DOES IT GET?

[21XDC]

You need br7's... The 8's are a colder plug.

[1PairOfChoppers]

Tom,

No, it's not the same. The X is a 1999 model year and the W is a 1998 model year. This could be an important fact for some parts. However, the pumps are the same part number.

I found the model number definition at boats.net when looking up your part. Scroll down and you should see the table.

Is regards to the plugs, I would think a colder plug would foul easier and not burn as clean as a hotter plug.

Later!
1PoC

[Tom 1]

I did change plugs to the correct ones and just received the fuel pumps that you suggested. Any hints for replacing them as this will be my first major mechanical undertaking for me on an outboard motor.

[1PairOfChoppers]

Hopefully I'm not too late with this post.

Do one at a time to ensure you don't mix up the hoses. Just take your time and think it through before you start. Stuff some rags under the pumps to catch any fuel that may leak when disconnecting the fuel lines. I think I also had some 3/8" or 5/16" dia. bolts to plug the fuel line if I needed. Have some small zip ties ready to put on the fuel lines to the new pumps.

You could also take some digital pictures in case you need to reference them later.

I'll take a look tonight at mine to jog my memory if there's anything else to add.

[Tom 1]

1Pair , it wasn't as bad as I thought. They came off no problem with some fuel spillage. I had the exact zip ties which worked perfect. When I took the old pumps off and took it apartone of the thin stainless flaps/valves was loose with the screw holding it almost falling out. Thanks again for the help. I just got back from the Northern Rally and the boat was screaming up and down Lake Cobosse!