225 pro max help

[RBT]

I am helping a friend with his 1997 225 promax. It is on his allison grandsport.

Last year it had a bog getting on plane. Service apparently hasn't been high on the priority list so it is getting attention now.

The way it is rigged, Holley red low pressure pump, to the diaphragm pump to the vst. Some one disabled the oil injection, but didn't remove it.

The owner wants to remove it correctly, I believe pro marine makes a delete kit. Anyone use it?

The diaphragm pump has also given them trouble in the past, because there Holley red is already in place it is to be removed. Does anyone know if there is a kit for this?

Because I am not super familiar with the pro max, my plan is to replace and clean all the rubber bleed lines with new tygon (they are suffering), injectors to Brendan, clean the throttle body (filthy was not the word for it), reeds are perfect. Do the correct delete on the oil injection and diaphragm fuel pump, put it back together and see if it clears the bog.

Anything else?

thanks

rt

[speedinstream]

I would lose the electric pump and use factory setup has always worked best for me dont run both u could also do a prostock setup with hi pressure pump in the boat with a regulator and a return just like race motors its alot cleaner looking gets rid of the vst tank. For the oil ingection go to any merc dealer and get the peice that replaces the pump basicly a block off plate with a piece that sticks in the block to keep the brass bushing from falling out

[RBT]

You bring up an interesting point, when I pulled the #2 reed cage out I found a piece of metal (actually looked like a piece of rod) about 1/4 x 1/4 inch, you can see in the motor where it has hit the crankcase. And where it has bounced off the reed cage. When I found it I could not believe ithadn't gone through the motor.
Being unfamiliar with the pro max, it assumed it was from the oil injection. Scary!
So I am assuming there is more?

The drag style fuelling has been talked about.

Ill take pictures.
Thanks for the help

[Dave Strong]

Is this going to be a lake boat or a race boat?

Dave

[RBT]

Lake boat/ kids skiing etc

[speedinstream]

Dont know what the rod your talking about could be but it sounds like trouble i dont think u could break the oiler shaft with a sledge hammer there is a brass bushing that it rides in that can fall out

[Capt.Insane-o]

Go through the fuel system in the boat, throw the holley pump away and rebuild the diaphragm pump. Pull the lid off the VST and check the needle and tank for debris. If it still has the plastic caged rod bearings replace those. Merc didn't get too much wrong with that motor. If he wants to get in and turn the key just put it back to teh way it came.

[tux974]

Go through the fuel system in the boat, throw the holley pump away and rebuild the diaphragm pump. Pull the lid off the VST and check the needle and tank for debris. If it still has the plastic caged rod bearings replace those. Merc didn't get too much wrong with that motor. If he wants to get in and turn the key just put it back to teh way it came.

Amen!!
Rob, IMPO I say forget that VST delete setup!

[wired247]

I like the VST delete. Makes things cleaner, easier to work on and simplifies things considerably. The only reason for the VST in the first place is so that Mercury could sell bolt on motor packages that did no require any mods be done to the boat. That is Mercury's problem. If its yours its your problem. Running an external HP pump set up like the HP motors run their eliminates several potential problem points such as the factory HP pump, needle and seat in the VST, the oil pump, VST filters, low pressure vacuum driven pump etc. Not only that but in pulling all those parts you go to a cheaper and easier to maintain /replace pump. I think Ive got $300 in my entire fuel system with a carter low pressure pump, Bosch 044 High pressure pump , surge tank, filters, lines and fuel pressure gauge. I can set it where I want pressure wise and that system will flow enough fuel to support 600 HP without trying hard. Its easy to work on and it does spill fuel, flood or cause me to do anything other than pour gas in the tank and run without worrying about it one bit.

[tlwjkw]

Go through the fuel system in the boat, throw the holley pump away and rebuild the diaphragm pump. Pull the lid off the VST and check the needle and tank for debris. If it still has the plastic caged rod bearings replace those. Merc didn't get too much wrong with that motor. If he wants to get in and turn the key just put it back to teh way it came.

yep!

turn key, pleasure/ski.. bone stock 'cept for tha oiler delete (oiler is optional if ya know its never been over heated or not (or gonna be) run past tha limiter).. .. rod bearings are fine to tha limiter, change when rebuild time comes around or if ya take it down for whatever reason.. probably tha best efi motor they built... hacked on motor is for "can do" hackers or wanna be hackers.........jmo

[Dave Strong]

Post a pic of your treasure you found, don't know where it would be from. If you pulled the injection pump and the shaft is still there the only thing it could be is one of the screws or nuts that hold the plastic gear on the crank?
As was said keep the stock pump and VST, if your taking the top off the VST make sure you have a new Oring. Never had much luck reusing them as the fuel and oil swells them.
If he can run good 91 premium cut the heads to 34cc get the link and sync bang on with pickup timing real close to 0-2adtc. Will need a tps tool to adjust it correctly.
If you need any of that info from the Merc manual let me know I can scan it for you.

Dave

[RBT]

Thanks for the tips, kinda new ground for me. All I really ever play with are 260-drag engines. I try and stay away from everything else.
I could use the service manual for the bleed lines/vst/fuel pump/oil pump stuff. Everything else is normal for me.

Thanks a lot for the help

[Dave Strong]

Thanks for the tips, kinda new ground for me. All I really ever play with are 260-drag engines. I try and stay away from everything else.
I could use the service manual for the bleed lines/vst/fuel pump/oil pump stuff. Everything else is normal for me.

Thanks a lot for the help

You will right at home with this, pretty much a 260 with oil injection and Laser EFI.
Will dig up the hose diagrams for you.
Still like to see a pic of that treasure that was floating around in cyl 2.

Dave

[Steve Pope]

That piece of metal you found could be drive gear retainer that the set screw threads into. If that is the case the crankcase will need to be split to remove the drive gear from the crankshaft and inspect for other damage.

[speedinstream]

That piece of metal you found could be drive gear retainer that the set screw threads into. If that is the case the crankcase will need to be split to remove the drive gear from the crankshaft and inspect for other damage.

Very good thinkin i had a motot that the tiny bolt from the oiler gear came out made a hell of a mess