2.5 150 ports

[rs2.2]

Hi,
Does anyone have any photos of the porting on a 2.5 150 versus a 2.5 200? Can the 150 be ported to 200 specs or is the liner different?
Thanks

[LakeFever]

I dont have pics but the exhaust chest is the most visibly different thing between the large chest 2.5 and the small chest XR6 style. Promarine lists all the sleeves for the 150 2.5 as having a notch with a different part number than the 200 2.5 so the transfer ports are also likely different too. It would probably take considerable block work to get a 150 XR6 block to large chest 200 hp 2.5 spec.

That said vkingmike runs dang near 90mph with an XR6 on his vking which is way faster than my old vking with 200 2.5 large chest ever ran which proves set up is far more critical than hp when it comes to peak performance. In other theads here a lot of XR6 owners mention it outperformed expectations.

if your rebuilding theres some great threads here if you search on porting providing you want to go down that rabbit hole

[David - WI]

I would think you could buy a 200 for much less than it will cost to "convert" a 150... there is more involved than just changing the ports. Sell the 150 to offset the cost.

[OnPad]

https://www.screamandfly.com/showthr...ort-maps/page2

Do a browser search for mercury 200 port map. If you still can't find a 200 map, I can probably dig one up.

Haven't looked inside a xr6, but was into a 175 a while back. It was a hot mess, exhaust notch, liner hanging proud of the block everywhere. I think improvements would be easily achievable with the CORRECT tools.

[derekfl]

I would think the exhaust caver from a 200 would help quite a bit.

[OnPad]

I would think you could buy a 200 for much less than it will cost to "convert" a 150... there is more involved than just changing the ports. Sell the 150 to offset the cost.

I'm still trying to get my 225, and 200 to be as fast as my 150!

[rs2.2]

Thanks for all the advice, the 150 is fully stripped down for a rebuild anyway so wanted to see while it was apart if there is anything that can be done to bring it up to closer to 200 specs. I can’t seem to find a 200 port map but will keep searching!

[OnPad]

This I believe is a 225 promax map, basically the same as 200, except the 200 doesn't have as much chamfer in the exhaust roof.

You can get away with cutting more on a light boat, less on a mid weight, no port raising on a heavyweight

What is the port height of your xr6? Exhaust roof, and transfer roof. I'll put it in my notebook.

[David - WI]

If you have to buy a different tuner, carbs or ECU, heads, plus open the exhaust plate & chest it will cost a lot unless you can do all the work and scrounge the parts.

[Baker343]

I'm grinding on one right now. Bought the 150 PH with 1 hurt hole for cheap. Had all 6 holes bored 0.20 because I had 5 lightly used pistons from a previous cold seized disaster. Plan on comparing this BB block to my stock EE that I put new rings on with 38cc heads and has completed the past two Enduros.

[OnPad]

Mid process on a 2.0, a few months ago.

Below is pic of a 95 200 block, I just cracked a head on.
Exhaust is 1.620 the rest are 2.175

[Baker343]

[rs2.2]

Thanks for all the replies, please see attached photos. I’ve got a set of .015” over pistons that will be going in once the blocks been ported and bored out. The liner is over hanging the exhaust port a fair old chunk too.

[derekfl]

i am stripping a 2.5 200 95 motor as we speak. so i have an exhaust cover, 200 tuner and will have some pics of an untouched orig exhaust cavity very soon. OK, this is an I believe unaltered original exhaust chest from the 95, 200 horse motor. And I can see some sharp edges that would be best to round off, especially on the inside radius of the bottom port.

[derekfl]

Exhaust cover. Is yours flat or curved? the top one is early 2.0 150. or is it all 150's? bottom is 200 hp. both 2.4 and 2.5. both the exh cover and the tuner will ship for 25 or less each. so will 3 carbs off this 200. carbs are 100. the tuner and exh cover are 50 for the pair. trying to make room in the box truck for a couple of inlines. this 18 foot allison doesn't need 400 lbs hanging off the back. and too much opportunity to see if i can make it do the airplane thing and start gaining altitude. from what i hear the flight is short and the landing unpleasant...