200xs optimax sst200 water pressure

[Carl Kinder]

Hi. We have a optimax 200 SST with 3 hours from new. After 3 min running it holds Bach and throttle is reduced. Scan says port bank EGT too high 68deg. Starboard bank 55deg. Throttle position sender reads 92%. Throttle flap is full open. Also reads water pressure at 41psi ?. My thinking is actual throttle is fully open but ecu thinks only 92% open. So running lean at top end ??. What I don't understand is why water pressure needs to be 41psi ??. Do we need to remove the stats in head . or should I look for blockage. All seams fine with water flow. And compressor is not hot.
Any help or ideas on please??
Thanks. Carl

[zul8tr]

Hi. We have a optimax 200 SST with 3 hours from new. After 3 min running it holds Bach and throttle is reduced. Scan says port bank EGT too high 68deg. Starboard bank 55deg. Throttle position sender reads 92%. Throttle flap is full open. Also reads water pressure at 41psi ?. My thinking is actual throttle is fully open but ecu thinks only 92% open. So running lean at top end ??. What I don't understand is why water pressure needs to be 41psi ??. Do we need to remove the stats in head . or should I look for blockage. All seams fine with water flow. And compressor is not hot.
Any help or ideas on please??
Thanks. Carl

If 3 hours from new why don't you take it back to the dealer for there suggestions? Being a race engine I suppose there is no warranty but Merc could still provide some help. I would not remove the thermostats if new and under warranty. Not aware of a compressor on an outboard?

Give Merc technical division in Fond du Lac 920-921-5330.

There have to be others out there that are familiar with this engine?

[Carl Kinder]

Thank you for your reply.
engine runs fine for 3 laps then starts to reduce throttle because port bank EGT sender measures 68 deg C. Dropped gearbox and removed stats and can blow through, so dont think we have a blockage.
I am still wondering if its the throttle position sender reading 92% when throttle flap is 100%. Thus making it run a little lean, by not giving full throttle enrichment.
EGT on port bank is reading 68 C, which I guess is borderline "hot" ??. We have good water flow from compressor tell tail, so I guess the block is filling up with water OK, As the compressor water feed is from the top of block I would have expected the scan to show the compressor was getting hot if flow of water was our problem ?.
I still dont understand why 41PSI water pressure, I know in stock engine poppet valve will regulate pressure to about 20PSI.
Its very frustrating, We have only a week before we make the long journey to Sweden for first round of F2 WC. It will be longer drive if we cant sort it. . . lol

[omcstratos]

Not aware of a compressor on an outboard?

All of the Opti motors run a compressor like the 'ole 2 stroke Detroit diesels. Verados run them too.

[mobil1]

Verado runs a supercharger, optimax runs aircompressor for the dfi system.

Do you have smartcraft that gives you the fault or the cds system?
Throttle flap doesnt do much, you can open it manually whem engine rus at idle without any diffrence exept sound.
Its all tps and tpi value that makes the engine gain rpm, why do you set throttle @ 92 and not 100% @ wot?
Engine is out break in mode?
Engine mounted to high?
Impeller ok?
Sparkplugs good?

41 psi, maybe bad sensor...

If engine is only 3hrs old i would also contact dealer you bought it from and explain the problem...
First 3hrs it ran ok?