2001 VMAX 250 Power Loss

Thread starter #1
Sorry if this is in the wrong forum but I have a question

I have a 2001 Yamaha VMAX 250. I was running 60ish down the lake and then it just bogged down to about 40ish and wouldn’t get back up to speed. When slowed down to idle speed, it was idling a little rough. No oil alarms or anything went off. Turned it off and back on and it was slow getting on plane and still wouldn’t get above 40mph. I have done no research or tried anything to diagnose it myself yet. Any thoughts on what the issue could be?
 

dsgbqc

Senior Member
Yes check your fuel filter. Had the same issue the fuel line was degraded and all the plastic lining in the fuel hose had clogged up the fuel filter. Clean fuel filter and replace fuel hoses.
 
Do a compression check on the cylinders, if all are pretty close and still have over 105 ish, its probably gonna be fuel related. Most electrical problems have quick jerks like your truck is skipping when you have a bad wire. The bogging down sometimes happens when you lose compression on one cylinder. I wish you luck!!
 
Check your spark plugs....if you see little metal looking beads...you have a major problem. I had a 1990 150 do the same and I had a cracked block one time and two years later I had a cylinder go...but the behavior of the motor was the same as you describe...
 

Burton

Senior Member
Maybe not a bad coil, but this is how mine acted:


I bought a new boat in 15'. When I ran it the first time, it would only run 30-32 mph and should run about 42 mph. Sounds very similar to your issue. After everyone telling me it was the prop, finally got someone to test it and it had a bad coil.

However, it was not running rough at idle. It just didn't have power to get to full speed.
 

MikeyD6

Senior Member
Do you have old gas in it? Sometimes gas that's been sitting in the tank awhile can get a little water contamination. Especially if its just the regular gasoline ethanol blend.

My boat would try to get up on plane then slow down and almost die. Start it back up, and it would do the same thing again. I topped it off with fresh marine gas and problem solved.

If that gas has been sitting awhile, try that and rule it out.
 
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