Mariner 150 2.0l mods

[merc1250bayliner]

I have the top speed bug. I'm working on building a 2.5 engine, but budget wise for this year I need to stick to the 2.0l.

The 150 2.0l is on a heavy deep vee 19ft runabout. Originally I was getting 36mph. After playing with rigging height and props I'm now at 42mph. I want 45-50mph.

Here's what I've done:

-Black boxes removed, timing at 22 degrees.

-Oil injection removed

-It has wmh 31 carbs with 62 main jets.

My plans:

-I'm having .080 cut off my heads. I CC'd them around 27.5cc with .080 cut off.

-Would stuffers be worth the effort for top end?

Any other ideas? How much increase will the increased compression add?

[4Speed]

I had a 1993 2.0 on a 18'6" closed bow Baja and only took the heads to 32 cc as I wanted to be able to run 87 octane if needed, added Boysen reeds and a G-Force tuner. Also added a hydraulic Jackplate and a slightly modified Mercury 25P Tempest propeller. With all the mods I went from the low 60's to the mid/high 60's MPH. I could turn about 6300 using the jack & trim. I also siliconed the top 2 water inlet holes in the lower as the speed didn't justify a nose cone. I could have gone further on the mods but I didn't want to loose the reliability and it wasn't really a race hull. Almost forgot, I added louvers in the cowling.

[merc1250bayliner]

Should I increase main jet sizes if I add louvers and velocity stacks?

[Baker343]

Are you running the stock air box. And I would say no anyways.
Your probably asking a lot of that 2L to push a heavy deep V to 50mph.
Go ahead and try cutting the heads and adding the stuffers.
What RPM's are you running at WOT and with what prop.
Mercury fishing motors have no problem running 64-6800.
Why are you running 22 degrees of timing.
Put that 2L on a lite Stream and you will see low 70's with some set up time.

[LakeFever]

Bump the compression, add the reeds, stuffers, steel cage bearings, rod bolts, xR2 carbs, run good fuel and find a good prop shop and spend 90% of your budget there. You won’t regret it

A guy I know took an XR2 2.0L with those mods to 80 with a DaH worked/labbed et on a valero. I believe they worked the prop 3 times to get it right, two times for sure but I think it was three trips in for work $$$ prop but he got the results he wanted

[merc1250bayliner]

I'm running a 16p enertia at 5300 rpm. I'm running 22 degrees of timing because that's what I was told to set it at with black boxes removed. Should I run less or more? I am aware that it would go faster on a different hull. I would like to work with what I have this year.

[wolfgangb]

Bump the compression, add the reeds, stuffers, steel cage bearings, rod bolts, xR2 carbs, run good fuel and find a good prop shop and spend 90% of your budget there. You won’t regret it

A guy I know took an XR2 2.0L with those mods to 80 with a DaH worked/labbed et on a valero. I believe they worked the prop 3 times to get it right, two times for sure but I think it was three trips in for work $$$ prop but he got the results he wanted

subscribed - especially the steel cage big end bearings and rod bolts. Without that, 6200 rpm is the limit!
A lot of people forget that with expensive results.
wolfgangb

[merc1250bayliner]

I don't plan on spinning it over 6000rpm. No one has answered back about my timing question? Is 22 too much?

[rock]

22 is safe.

Rock

[Baker343]

As Rock said 22 is very safe. With the boxes removed you can run 24 to 25 also but would probably only see a slight performance gain on a lighter setup.
Once you complete your mods, check your compression, run the proper octane, read your plugs and start bumping your timing 1 degree at a time. Play with it and see what happens.
I still think testing props and engine height will probably give you more bang for your buck

[merc1250bayliner]

So far my mods I'm doing are


Velocity stacks
Louvers
Tuner
Shave heads

[merc1250bayliner]

I decided not to use the velocity stacks because the more reading I do it just says they don't do anything. I am going to do the reeds and stuffers, louvers, tuner, and shaved heads. From my work on car engines I know that to increase power you want more air in and more air out, and squeeze it harder. So hopefully these mods will make a difference. When I took the heads off I noticed there still is cross hatching on the standard size bore. The previous owner must not have run it much. One thing I'm not sure of is what reeds I need. I'm assuming 5 pedal. Do I have a vertical or horizontal intake on this 93 Mariner 2.0 150?

[Baker343]

I believe all fishing motor 2L started as vertical front half's.
And I think in the early 90's the 2L blocks started receiving top guided rods.
Post some pictures

[FMP]

I decided not to use the velocity stacks because the more reading I do it just says they don't do anything. I am going to do the reeds and stuffers, louvers, tuner, and shaved heads. From my work on car engines I know that to increase power you want more air in and more air out, and squeeze it harder. So hopefully these mods will make a difference. When I took the heads off I noticed there still is cross hatching on the standard size bore. The previous owner must not have run it much. One thing I'm not sure of is what reeds I need. I'm assuming 5 pedal. Do I have a vertical or horizontal intake on this 93 Mariner 2.0 150?

http://profblairandassociates.com/pd...mouth_Sept.pdf

[tlwjkw]

Do I have a vertical or horizontal intake on this 93 Mariner 2.0 150?

yours should be horizontal.. tha vertical stuff went away when everything went ta "fat block"...