Yamaha HPDI 300HP Problems

[Kipstone]

Hi All
I have problems with my 2006 HPDI 300HP on my 1976 rebuilt 23 Seacraft. Ive recently purchased the boat and only used it a couple of times after winter storage. The tanks were 3/4 full. On first lengthy running of 30 mins at 3,500 the engine lost power and would only rev to 1500 but no warnings went off so it did not go into safety. I just got home but then would only start to tickover and cut with any throttle. Now it will not start at all. Ive cleaned the main and engine filters and checked the plugs. Any ideas? Ive seen lots of issues on Forums but just help in identifying the problem would be of great assistance. Thanks in advance

PS Also thanks to those who gave me great advice on my recent trim tabs question

[77SceptreOB]

Ethynol gas related? Water in the tank? It's probably fuel related. Try running it on a fresh 6 gallon tank of ethynol free gas, see if it runs okay. Then you'll know if it is motor related or fuel related.

[doodlebug]

Sounds like no fuel pressure, I lost one of my high pressure pumps on my stbrd optimax 2 weeks ago 3000 to 1500 to dead and would not start again in about 100 yards. After I got home and checked fuel pressure problem was discovered 300 dollars later it's all better.

[GodsReel]

hopefully that is all it is , there is lots of good info. on the hull truth site about all the updates that were needed for those motors , that sounds similar to some of the problems i heard of. check the fuel then have it put on a laptop and see if updates have been done.