Opti low rpms

[Motv18]

Three pumps iirc on a 225 two in the vst one outside. The one outside is the square one mounted to the vst. Sounds like your good there though. It’s a vacume diaphragm pump revived a upgrade around 05.

Humm wonder if you got sold a 175 or 200. Power head. That would definitely cause a rpm problem. Have your guy run the pn#

the 1.5l are alot alike except throttle and computer easy to have them get crossed up. Assume the v6 is about the same

[billybob]

OK 2 things on opti that can drop top rpm. as motor gets older, TPI does not read high enough. I have replaced TPI on motors & they regained rpm. No you cannot bend link rod it will idle higher. TPI voltage needs to be near 4.3 volt at full throttle. Secondly I,ve done 6 or 8 like this. merc tech. did not believe me. my TAM[technical accounts manager] did not believe me. The exh. adaptor gasket can blow, dumping excess water in tuner. It doesn,t leave enough room for exh. WHaaaT yea really. Simply remove l/u & look for shiny spots in exh. in dr. shaft hsg. it will be covered in carbon so shiny spots, bare alum. will be obvious. the reason it happens is torque fpr p,head mt. nuts is only like 18 ft. lb. so when run in rough water. parts will move around causing gasket to blow. I am not saying that,s it. but every 3 litre I pull l/u I look up there. I,ve done at least 6. If that,s what problem is do not overtorque mt. nuts, it will distort cyl. # 6 & blow that cyl.

[Loxboy1]

The p/n on the ecm, intake handler and bracket all match and comeup as 2002 225hp 3.0l. I fixed the hard start issue by repalacing the torn fuel reg and air reg diaphrans.

[Loxboy1]

OK 2 things on opti that can drop top rpm. as motor gets older, TPI does not read high enough. I have replaced TPI on motors & they regained rpm. No you cannot bend link rod it will idle higher. TPI voltage needs to be near 4.3 volt at full throttle. Secondly I,ve done 6 or 8 like this. merc tech. did not believe me. my TAM[technical accounts manager] did not believe me. The exh. adaptor gasket can blow, dumping excess water in tuner. It doesn,t leave enough room for exh. WHaaaT yea really. Simply remove l/u & look for shiny spots in exh. in dr. shaft hsg. it will be covered in carbon so shiny spots, bare alum. will be obvious. the reason it happens is torque fpr p,head mt. nuts is only like 18 ft. lb. so when run in rough water. parts will move around causing gasket to blow. I am not saying that,s it. but every 3 litre I pull l/u I look up there. I,ve done at least 6. If that,s what problem is do not overtorque mt. nuts, it will distort cyl. # 6 & blow that cyl.

I swaped the tpi with a known good one and it made no difference. You abreviated alot so im not exactly sure what your point at lol. Are you saying to inspect the round cover playe bolted below the powerhead on the starbord side of the shaft housing?

[Motv18]

Cool how’s the track diaphragm

[billybob]

I am not saying that is definitely problem, it needs to be inspected. If you remove l/u, tilt motor up, look up inside dr. shaft hsg. with good flashlight. if you see shiny spots, bare aluminum. chances are, the exh. adaptor gasket is blown. you may even see it protruding, into tuner. it can reduce top rpm. stupid question, but did you have someone full throttle it [not running] & check for complete throttle opening. If you have foot throttle, stop screw may have migrated back. you may save time & money by going to merc. dealer & have checked, on CDS, [computer diagnostic system].

[Loxboy1]

hey guys been busy and haven't gotten to reply,

last weekend we took the boat out and were running on plane, i was able to go to the stern and look at where the water is against the lower. i have water coming up over the second from the bottom vent plate, so im thinking i need to raise the motor up maby 2 holes.

[flabum1017]

hey guys been busy and haven't gotten to reply,

last weekend we took the boat out and were running on plane, i was able to go to the stern and look at where the water is against the lower. i have water coming up over the second from the bottom vent plate, so im thinking i need to raise the motor up maby 2 holes.

The water should be hitting about an inch or so below the cav plate above the prop

[flabum1017]

Prop should be slightly ventilating

[Loxboy1]

Prop should be slightly ventilating

nope, mine definitely does not look like that haha. i made the mistake of not recording where the orig motor was mounted. you thinking 2 holes is good or too much?

the motor sits on a stainless marine bracket that sets the motor im guessing around 2 foot off the transom and the hull has a deep V

[nitro_rat]

you thinking 2 holes is good or too much?

Measure from where you are to where you want to be and compare to the distance between holes, just keep an eye on the water pressure gauge once you make a move!

[Motv18]

I gained 10 mph just by raising my 90. I imagine the steering feels heavy as well.

[Motv18]

Just thought to add, with the manual I think section 2c? Has the throttle synch info and 1d? The remote cable set up for the throttle. Low tps can be caused by that adjustment, and throttle cam wear can close up the throttle plate, remote throttle cable stretch can prevent wot being reached. Double checking after a repower won’t hurt anything.

[flabum1017]

From what he is describing, his engine is too low. My friend bought a brand new 27 Concept, they rigged the bracket too low and he could not get over 50 with twin 225's.... raised the bracket, raised the motors all the way up, now he hits 72

[Motv18]

Yep, along with water in his fuel from another thread, I just added that since it was the first thing done, and the synch may be off on this new motor. Along with it set to deep.