Starting Issue 2003 VMAX 225 OX66

[Amistad Tackle]

I have posted about this issue before and never figured out what is causing it. Here it is again this year with a new twist and maybe someone has solved the same issue in the interim.

Mt 2003 225 OX66 Vmax (VX225TLRB) generally runs like a top. I have one issue and that is when you have a cold day to start off and then it warms up later in the day (generally in the spring months). Under these conditions I sometimes have a hard time getting the motor to start. It is like it is starving for fuel. I can tilt the motor up a ways and then it has always started. Here in the last couple of months a new twist has happened as the motor has run out of fuel on me when I go to take off. This has happened twice both times on warm afternoons after a cold morning and then fishing in one location for a while. After the motor shuts down I can go back and pump the bulb up hard and then it runs fine again. It is like the fuel has siphoned back into the tank despite the one way valve in the engine fuel line (have replaced this also) after the motor fuel filter. These symptoms only happen when it is cold and then gets warm/hot later in the day. If it is hot/warm to start off or stays cold all day never have an issue.

I have two 32 gallon fuel tanks, then a fuel selector switch, then a water separating filter, then bulb, and then on to the engine. I replaced the primer bulb last fall and the needle valve in the VST several years ago and it still does this. I have also replaced the fuel line from the water filter/separator to the engine. I have cut the tank lines at the tank barbs and reattached them to make sure I was getting a good seal. I removed a anti siphon barb at one of the fuel tanks and replaced with a regular barb. The other tank just had a regular barb. The bulb pumps up like it is supposed to and is next to new. I think I must be sucking air somewhere in the fuel line, yet not leaking fuel. I have a manual fuel selector switch that allows you to switch between port and starboard tanks. I cannot say if this only happens on one tank versus the other. The switch is original to my 1999 Ranger 492VS but seems to function like it is supposed to. I am going to replace that next thinking it is sucking air there. What confuses me is that tilting the motor allows it to start, which to me says maybe the needle valve in the VST is the culprit. Upon dissasembly and inspection the float in the VST has looked fine. To me the needle valve also looked good. Though maybe I was getting vapor lock in the tanks but open the fuel caps and do not get any rush of air into the tanks. The recent shut downs may be a completely different issue, but it happens under the exact same circumstances as the non-start, which makes me think they are related.


Anyone experienced this issue or have any better ideas on how I might diagnose? Anything else I might take a look at? Thought about using some clear line to look for bubbles in the fuel to isolate the issue. I have a mighty-vac and thought I could vaccum/pressure check each section of line. I am going to be pulling the bench seat anyway to replace the fuel selector switch so have access to all the fuel lines.

[javelin90]

Couple of things,

Has the fuel pressure been checked?
Has the VST Tank filter been replaced?
How old is the fuel primer bulb?

Do you have access to a portable gas tank? If so i would suggest that and see if it improves.

[21XDC]

These random fuel symptoms sound like a potential bad fuel pump relay to me

[Amistad Tackle]

Thanks for the suggestions.

Have changed the relay. Fuel pressure is fine. VST filter is fine. Primer bulb is almost new.

Not a random occurrence. Only happens under the conditions I described.

I knew it was a long shot. If I figure it out I will post the cure. Once it warms up it will no longer happens. Been fighting this for 15 years. I am almost sure I am sucking air into the fuel system somewhere. Once I rule that out I will look elsewhere. Real pain in the arse.

[CJ1]

A holley red fuel pump was the best thing I did for mine other than the HT parts. Cj

[JoeFriday]

Check the wires grounded on the rear top port side of the motor. Mine had corrosion and it had a lot of weird symptoms.

[Amistad Tackle]

Ran like a top this week in the cold. Four days straight without a hiccup.

[Amistad Tackle]

Today 45 degrees this morning and 80 by this afternoon. Had a hard start situation this afternoon. Trimmed the motor up and pumped the bulb. Started and off we went.

[JoeFriday]

Have you done the low pressure fuel pump delete? I used the Walbro and mounted it on the motor. That was worth the effort.

[Triton420]

You have a bad fuel pump relay, bad fuel pump resistor or bad HP pump. This happens to mine every so often. I hate spending $300 on a damn relay again just after 2 years so what I did is run a +/- wire from battery to engine. When it happens, I unplug the HP pump, connect my leads to pump and then battery (unhooked when not needed) boat then runs fine and will not be stranded on the water.

[Triton420]

Have you done the low pressure fuel pump delete? I used the Walbro and mounted it on the motor. That was worth the effort.

LP delete will not help him when the HP pump is not turning on.

[Amistad Tackle]

Fuel pump resistor? I will have to look that one up. I have changed the hp pump and the relay. My engine also smokes like a smoke stack at start up if that adds anything to the discussion. I have changed the two o-rings on the oil pump trying to remedy this. I am going to check the fuel pumps in the morning to see if one is leaking. Since I posted this it has run without a hiccup, but it has generally been cold when I have been out.

[CJ1]

Fuel pump resistor? I will have to look that one up. I have changed the hp pump and the relay. My engine also smokes like a smoke stack at start up if that adds anything to the discussion. I have changed the two o-rings on the oil pump trying to remedy this. I am going to check the fuel pumps in the morning to see if one is leaking. Since I posted this it has run without a hiccup, but it has generally been cold when I have been out.

This was also a issue on mine with the LP pumps. I had it fixed for awhile then it started smoking at start up again, BUT I also had the rpm drop/fade at WOT. Ended up being a bad O2 sensor that time. Engine has been perfect for a few years after sorting it out. CJ

[Amistad Tackle]

My top fuel pump was leaking badly. Pouring fuel. I had just changed it at the end of January. Pulled it and rebuilt with a Sierra kit. I bought that pump on Amazon because it was cheaper than Sim and it was genuine Yamaha, but who knows it may have been very old. Other two pumps were fine. Also replaced the fuel tank selector switch. Will see how it goes with the warm weather we are getting.

[ctmatz]

had the same problem replaced the primer bulb problem gone

[Clcuny]

I have the exact same issues as you're having. Runs like a top when you cold start the motor with no issues when driving at high speeds. Get to my fishing spot turn the motor off, turn it back on and it turns right over. Turn it off, drop the trolling motor and fish for 30-45 minutes and then it wont start. Check the HP fuel pump and I have no pressure at the pump. Bulb is no longer hard but able to pump hard and get fuel to the fuel filter. I've replaced the HP fuel pump and low pressure fuel pumps. I'm thinking it has to be electrical related?

Can you tell me what relay you replaced?

[Amistad Tackle]

Fuel pump relay. It's in the black box on the starboard side of the motor. This year I replaced that again at $249 (ridiculously overpriced) and the primer bulb (used an OMC which I heard are the best), the manual fuel tank selector switch, and all 3 low pressure fuel pumps. Still have the starting issue. It starts every time when I trim the motor up and otherwise runs like a top, so not like it leaves me stranded. Just going to live with it.

I have not had to pump the bulb lately and no more taking off and running out of fuel, so I think I did some good with what I did.

[JoeFriday]

Since you mention the tilt deal, I wonder if maybe the float in you VST is out of whack. I still would check all the grounds. When those get corrosion, the symptoms get weird.

[Amistad Tackle]

Have removed all grounds and cleaned them all up. Still did it. Float could be an issue. Today it was hot. Put in at noon and pulled out at dark. Never missed a beat and never had a starting issue. It baffles me as to what causes the starting issue at times.

[96 Champ]

I have the exact motor but a 2000, just recently bought the newer rig last August, took it out for a week this spring a couple weeks ago and experienced the same problem, on cold start up and after fishing for a bit, all at night when temps dropped. Thanks for the post.