Yahama 2 stroke 200HP HPDI not getting above 3400RPM

[redbay 7.4]

I need help

I have a Yamaha 200hp 2 stroke HPDI with only 155hours on her.
On starting she will gain about 4400RPM and back right off to 3200/3400RPM after a few minutes. There is no alam going off but seems like engine is going into limp home mode. I have had the following done to the engine~:

• Fuel Filters cleaned (not replaced)
• Low pressure pumps checked
• Fuel line checked
• Compression checked
• Removed and cleaned all 6 injectors
• replaced all plugs
• Cleaned VSP
• Checked water sensor (not cleaned)
• Computer hooked up and showing no faults

Am I missing anything. Its getting very close to Calves week and need the boat working. Hopefully someone will have some tips. Thanking ye all in advance.

[nan-ber]

have not worked on one off these yet,but i know that t high pressure pump can give trouble, NOW HERE S the trick or so i m told ,there s a filter in t pump that can block, check that out it just may be t trouble. goodluck

[Robbie Diesel]

Hello! I have a 300 HPDI and over a year ago had small issues where at Wide open throttle it would reach the full 5500rpm but then slowly fade away and drop to 5400rpm then 5300rpm 5200rpm. I e-mailed a company in America that i buy all my yamaha spares from and he said to replace the Fuel filter screen in the VST tank (cleaning it will not do) and also the metal in line filter located directly above the VST tank. This COMPLETLY cured my engine and it runs like a scalded cat. Heres a couple of pics of the 2 micron in-line filter above the VST tank. They also recommended replacing the low pressure pumps at around 200hours to avoid any problems. (they were ony £35 each)

Hope this info Helps

Robbie

[verstappen]

@ redbay 7.4

In your listing I am missing the extra large 10 micron external fuel filter + waterseparator what should be between your tank and your engine.

The smal service filter and water separator under the engines hood surly isnt 10micron, because i cannot imagine this smal piece flowing 100ltr per hour at WOT.
My gues is its a 50micron.

So when you do not have the 10 micron external, you bet, you have problems from there.

My tip.
Check this transparent bowl, i could not get the bowl back fitting, the o-ring did not get into compresion, pumping the ball showed this minimum leaking and this also giving a vacuum leak if i should have started the engine which i didnt because of early finding.

Further will advise you to replace all filters if in doubt and regarding above when no external.

Faulty codes should be seen at dealers when ECU is monitored witht laptop.

Send pm and email adres, and i can send you page copy yoy like of private manual 250 and 300 engine.

Appriciate you give feedback what curred your engine later.

Succes