Dropping a 2006 175 Optimax powerhead onto a 1995 175 carbed

**Onetime** · 10-01-2017, 05:03 PM

That's a good price! You did good. Post how it all works out.

**Fishinmymission** · 10-02-2017, 03:51 PM

Also I was not happy with the first response I got from Mercury about smartcraft rigging to view fuel consumption. They basically stated that only a dealer could answer rigging and gauge questions. So I asked again and got an extremely helpful response about smartcraft rigging and a product that came out last year called vessel view mobile. Basically for all mercury engines after some year in the early 2000s (not sure if it includes racing engines) this harness with a massive bluetooth emitter mounts under the cowl and clips into an existing wiring harness to transmit all the engines data including error codes to the Smart phone app. I think it gives MPGs and such utilizing the phones GPS.
Also I misread the parts list and my engine shared the same longer tuner so I dont have to remove my tuner or lower exhaust plate. Aiming to drop on the head next week.

**Fishinmymission** · 10-08-2017, 09:04 PM

Anyone know what the boot/grommet is called or part number for it that goes into the fishing cowls 135 hp to 175 hp from like 1996 to 2006. I have my cowl but its missing this I can't find the part# for the piece the hold the fuel connection and control cables. Can't find any good pictures of this either.

**Dopey69r** · 10-13-2017, 06:55 AM

I have parts for a 2002 200hp xs 2.5l for sale if any will fit. So far I still have everything except. The lower unit. It was serial # OT430397.

**Fishinmymission** · 10-13-2017, 11:23 AM

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Thanks guys I love this forum so much. So I found the clamp and I was still like how the hell do my controls get rigged into this thing. If you didn't have picture of the original rigging from this clamp you need this one page from the 500 page service manual to figure it out. I also compared the 175 blackmax cowling to the 135 optimax cowling and I almost guarantee it would have fit in my old cowling. The opti cowling is ever so slightly bigger but Ill drop my black max cowling on just to check.
The one thing the optimax cowling has though is the opening for the fresh water flush and it fits and clamps together much more easily. Both sets are the same weight. Air flow in the optimax cowling enters the top back then travels to the bottom front through this duct. The blackmax air flow just enters the back top. Who knows if either provides certain benefits.

If I ever want more power with fuel efficiency in the future I would come here to look for an xs powerhead.

Had a shipping delay but my powerhead should arrive next week.

**Fishinmymission** · 10-27-2017, 05:48 PM

Does anyone happen to have the wiring diagram for a 2006 135-175HP optimax? The powerhead arrived and is on the motor. Just have to finish connecting everything and I feel like I might want this. I have the 2001 diagram but there are some differences. I only replaced 6 of the 10 powerhead studs that were damaged because i could get nuts on to the others while it was hanging in the air. In hind site this was a mistake because once you're working in the tight space on the motor it's very difficult to get slightly old threads started. Fingers crossed I don't mess up a thread and have to pull it again.

**Varmint** · 10-29-2017, 02:22 PM

ya you would need a newer hood, or an alien,due to alternator on later 01 up 2,5's

**Varmint** · 10-29-2017, 02:24 PM

I always put the 4 rear corner nuts on, and start them before i fully lower the PH,easier,they can be a bear once PH is fully seated.even more PITA with alien pan

Originally Posted by Fishinmymission

Does anyone happen to have the wiring diagram for a 2006 135-175HP optimax? The powerhead arrived and is on the motor. Just have to finish connecting everything and I feel like I might want this. I have the 2001 diagram but there are some differences. I only replaced 6 of the 10 powerhead studs that were damaged because i could get nuts on to the others while it was hanging in the air. In hind site this was a mistake because once you're working in the tight space on the motor it's very difficult to get slightly old threads started. Fingers crossed I don't mess up a thread and have to pull it again.

**Varmint** · 10-29-2017, 02:29 PM

it is bigger due to electrics and more chit hangin off the opti PH,mostly when they intro's alternators in late '01 on the 2.5,it is why the new 225x has an alien hood,old style rubs alternator.

Originally Posted by Fishinmymission

Thanks guys I love this forum so much. So I found the clamp and I was still like how the hell do my controls get rigged into this thing. If you didn't have picture of the original rigging from this clamp you need this one page from the 500 page service manual to figure it out. I also compared the 175 blackmax cowling to the 135 optimax cowling and I almost guarantee it would have fit in my old cowling. The opti cowling is ever so slightly bigger but Ill drop my black max cowling on just to check.
The one thing the optimax cowling has though is the opening for the fresh water flush and it fits and clamps together much more easily. Both sets are the same weight. Air flow in the optimax cowling enters the top back then travels to the bottom front through this duct. The blackmax air flow just enters the back top. Who knows if either provides certain benefits.

If I ever want more power with fuel efficiency in the future I would come here to look for an xs powerhead.

Had a shipping delay but my powerhead should arrive next week.

**Fishinmymission** · 11-03-2017, 04:05 PM

So I need a little help. I'm doing this on the water btw and only dropped one box wrench so far. My Marina was kind enough to lift off my old head and drop the new one on. So I have the water from my thermostats and the bleed air from my fuel rail pressure regulator that needs to go to exhaust. I only have one exhaust return fitting in my exhaust plates. Can I T my thermostat exit water together than t that to the bleed air and have everything go out that one fitting in my exhaust plate or will water back into the pressure regulator or air into the thermostats? How did you guys who converted the xs motors do this??? I'm pointing to the bleed air line hooked up to my exhaust already and you can see one of my thermostat lines hanging which need to also be routed to exhaust.

**Fishinmymission** · 11-03-2017, 06:40 PM

Ok so looking online i think there are some lower exhaust plates that have 1 or two fittings for the thermostat outlets(pulled first two photos below from ebay). I remember seeing this before I started the project yet then i saw plenty of 18233A20 lower exhaust plates on ebay that didn't have these ports so I figured it wasn't needed, this was wrong and i think those parts were mislabeled.
It's too risky to combine the air and coolant into the same lines.
So I have a backup plan which if you look at the third picture you will see my old carbed upper exhaust plate I will remove this fitting from my carbed upper plate and drill and tap the opti lower exhuast plate in the same places as shown in the first two pictures and install this fitting and buy one more to install. The coolant passages are exactly the same in both my carbed and the opti upper and lower plates except the OPTI exhaust plates have two fittings for thermostat water in the lower plate and the carbed had one fitting for thermostat water in the upper plate. I should be able to do the drilling and tapping at the dock. It is a standard 1/8 NPT thread on my old motor that both Tstat lines were tied into so putting two of these fittings in the lower plate should work perfect. I think the new design has less a chance of burning up your exhaust housing and prop seals if debri were to clog the tiny coolant holes that were previously used in the upper plate old design cooling.

One more thing I haven't seen yet is where is the bleed air to pressurize my remote oil tank. I'll look harder tomorrow.

**Fishinmymission** · 11-03-2017, 07:12 PM

fWierdly there is a capped brown and white wire coming from the engine and my old trim sensor is a brown and white wire and not plugged into anything but I don't think they go together...
And then last thing I cant figure out because I dont have the 2006 wiring diagram is where this yellow and white, light green, and black and orange wire go. I found a picture on Ebay and they are hooked up to a yellow purple and black wire but my engine doesn't seem to have this...
Update the wires were for the digital trim sensor. I should be able to plug my old analog one into the brown and white.

**rock** · 11-04-2017, 08:17 AM

According to my xs manual the thermostats dump into the exhaust and the compressor goes to the tell tale in the cowling. The pressure for the remote tank comes from the starboard side of the block at the bottom and front below the starter.

Rock

**Fishinmymission** · 11-04-2017, 08:26 AM

Thanks found the bleed air for oil tank. And water from my compressor also goes to my tell tale but I have air coming from fuel lines that needs to go to exhaust as well. I think I have it all figured out but would still appreciate pictures of the lower plate if anyone owns a 2.5l dfi with two exhaust plates. Any stock optimax or 200xs. Not you guys who modified your one piece plates. I'm tapping today regardless.

**Onetime** · 11-04-2017, 09:24 AM

No hoses go into the lower plate. Everything goes into the upper plate.

Two hoses on the side of the plate. One feeds water to the compressor and has the strainer screen. Not seeing in your photos where your compressor is getting its water. Very important that the compressor gets a good source for cooling water. The other hose on the side of the plate is the hose from the injector rail.

The thermostat cover hoses go to the fitting in the rear of the plate.

This is us all from a 200XS with two piece exhaust plate.