2.0 Questions

[TNRoostertail]

I have an 82 150 Mercury Black max. I was wondering how much a set of 33cc heads and a good set of reeds would help these engines. And what rpm's do you guys run them while keeping longevity in mind? Thanks

[nitro_rat]

Not sure what cc the stock heads are, you can go down to 26cc with good gas. The vertical 2.0's really like Boyesen reeds, I've seen over 8,000 RPM with them on a stock 2.0. I have had excellent reliability up to 7500 RPM's but you need to make sure you're dealing with a healthy candidate! Keep a good impeller in it and make sure you have a good water pressure gauge hooked up. Keep the prop pitch short and let it wind...

What hull are you running it on?

[TNRoostertail]

Not sure what cc the stock heads are, you can go down to 26cc with good gas. The vertical 2.0's really like Boyesen reeds, I've seen over 8,000 RPM with them on a stock 2.0. I have had excellent reliability up to 7500 RPM's but you need to make sure you're dealing with a healthy candidate! Keep a good impeller in it and make sure you have a good water pressure gauge hooked up. Keep the prop pitch short and let it wind...

What hull are you running it on?
Thanks for the reply Rat. I should have clarified more on the engine. Its a V6 black max motor, and its up to snuff on mechanical. Carbs just rebuilt, new impeller kit with housing and fresh lower unit oil. It runs great, would just like a little more. I don't have any delusions of grandeur lol, I know it will never be a 225 promax. It is on a 1700 Super Vee norris craft, so pretty lite boat. I would also like to do the exhaust mod to the mid some time.

[nitro_rat]

That hull should run out ok with a 2.0. What carbs do you have (WH#)? I know '81 had the tiny venturi and '83 had the big ones, don't know about '82. I would get a set of Boyesens, and some solid mounts if you don't already have them. Installing the mounts will be the perfect opportunity to chunk the liner out of the can and drill it. I would contact James Perry about cutting your heads. He'll know exactly what to do depending on what gas you're planning to run. He cut a set to 26cc for my little 2.0. I would keep an eye out for a light flywheel, your top bearing will thank you if you do long runs at high RPM's.

[TNRoostertail]

That hull should run out ok with a 2.0. What carbs do you have (WH#)? I know '81 had the tiny venturi and '83 had the big ones, don't know about '82. I would get a set of Boyesens, and some solid mounts if you don't already have them. Installing the mounts will be the perfect opportunity to chunk the liner out of the can and drill it. I would contact James Perry about cutting your heads. He'll know exactly what to do depending on what gas you're planning to run. He cut a set to 26cc for my little 2.0. I would keep an eye out for a light flywheel, your top bearing will thank you if you do long runs at high RPM's.
Right on, good info rat. The carbs didn't seem tiny, looked real similar in size to my 88 150 engine. I can't quite make out the number but it looks like wh12 or wh17. I am attaching some pics so you guys can take a look. The number plate on the transom mount says the engine is an 82 but once there this old you never know. I'm not familiar with 2 piece heads from the older models so idk if these are 2 piece or not. I will definitely do some solid mounts and will ditch the can then. I know it has a can because it's awfully quite and I like loud lol.

[TNRoostertail]

Also want to clarify, these are older pics. This was when the engine was on the old procraft hull. The carbs are nice and shiny now and the engine is cleaner lol.
And as far as rpm's, I would like to turn this little fella around 6200-6500 rpms if thats a stable number.

[Merc 2.5]

R you sure it's a 82? U got newer head bolt pattern and enrichment, my 82 was old style , u sure not a 83?

[TNRoostertail]

R you sure it's a 82? U got newer head bolt pattern and enrichment, my 82 was old style , u sure not a 83?
I mean I'm not 100% positive, thats why I posted pics. The serial says its a 1982, but I know in 30 years things can get swapped around and what not.

[TNRoostertail]

Here is the serial.

[nitro_rat]

R you sure it's a 82? U got newer head bolt pattern and enrichment, my 82 was old style , u sure not a 83?

My '81 had the enrichiner, when you say old style do you mean choke plates?

[Merc 2.5]

My '81 had the enrichiner, when you say old style do you mean choke plates?

Yep ,head bolts etc

[TNRoostertail]

Well I'm kind of confused now. That wont make a difference on reeds or the can will it?

[Merc 2.5]

Well I'm kind of confused now. That wont make a difference on reeds or the can will it?

Sry bud. No difference, cut heads , reeds, can, prob a rejet to

[nitro_rat]

Rooster, your motor has the newer style enrichiner. That's good. With the old style choke plates you had to crank the motor over for 20 or 30 seconds to start drawing fuel in. PITA!!!

You also have the late style heads, again, a good thing. You can upgrade to the newer style one piece heads for a slight improvement in cooling.

[TNRoostertail]

Thanks guys thats good to know. Does anyone ever just sell precut 1 piece heads on here? And is it trust worthy? That way I wouldn't have a turn around. And what do you suggest on rejetting? Thanks again you 2.

[Merc 2.5]

There plenty 1 piece heads floating round with what u need, or bunch guys on here can cut u what u need b4 shipping. Contact rock here. He has lots heads , or chris Carson, I'd pitnup a wanted ad

[TNRoostertail]

What size cc heads should I look for? I already run premium fuel. Thanks

[TNRoostertail]

Hey guys, tried to do some more research on my engine. I found that my carbs are the good one I believe. They have the 1374-5427 casting numbers. From what I read this makes them the bigger venturi. I am now on the hunt for some 1 piece 28cc heads and am taking the can out this weekend. Tha is for your help.

[Gordon02]

I have this info that might help you identify carburetors....I'm building my own 2.0.....Gordon

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[Gordon02]

On the can and exhaust, I chose to keep the can in place so the super-heated water would not dump onto my waterpump. Here is my "un-proven, un-tested" solution. Gordon

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[TNRoostertail]

Looks like you have just holesaw cut holes into the can. What size holes did you go with? And the last pic is a cut down tuner?

[Gordon02]

I made a pattern for the exhaust housing out of 1" white oak scrap so that I'd be sure to have 5 evenly spaced holes on each side of the housing (seen in the 2 photos - left and right). The front 4 on each side are 3/8" while the rear one is 1/2" in each housing. The can holes are 1" each, so plenty to relieve the exhaust during initial rev-up from idle. I have a short-shaft (Promax SS) on my Allison that I bought new 20 years ago. One attribute it has over every other outboard I've ever run is that from idle to full rpm, is the absolutely awesome holeshot. The engine never bogs and there are no lost seconds waiting for the water column in the lower unit to be moved by exhaust pressure. The whole idea of the holes for me is not noise, but rather the instant throttle response and holeshots.

I urge everyone to respect our neighbors - in fact I am really against noise since I often fish near docks early mornings and late evenings. Open exhaust, no can, over-hub props, and 6,000 rpm holeshots are not my thing. I run a 26 Trophy 4 blade on the Allison/Promax SS so I can sneak away from docks and plan to do the same on this 2.0L when I finally get it built and find a boat that I want to put it on.

That is a 2.4 Bridgeport exhaust tuner # 41941 coming directly from the pages of Bass & Walleye Boats Magazine "Hot Rodding the Mercury 150 V6" October 1998 issue article. I found it on eBay, beadblasted it, and painted with Epoxy coating. Gordon

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[4Speed]

I had a 1992 2.0 V6 Mercury I purchased new...
Put a G-Force tuner, two stage plastic reeds and had the heads cc'd to 32. I ran regular 87 gas and turned it to about 6400 on a Baja 186ESS. Picked up a few MPH. Went from a stock laser II to a slightly modified (Rich Booger)Tempest

[TNRoostertail]

I made a pattern for the exhaust housing out of 1" white oak scrap so that I'd be sure to have 5 evenly spaced holes on each side of the housing (seen in the 2 photos - left and right). The front 4 on each side are 3/8" while the rear one is 1/2" in each housing. The can holes are 1" each, so plenty to relieve the exhaust during initial rev-up from idle. I have a short-shaft (Promax SS) on my Allison that I bought new 20 years ago. One attribute it has over every other outboard I've ever run is that from idle to full rpm, is the absolutely awesome holeshot. The engine never bogs and there are no lost seconds waiting for the water column in the lower unit to be moved by exhaust pressure. The whole idea of the holes for me is not noise, but rather the instant throttle response and holeshots.

I urge everyone to respect our neighbors - in fact I am really against noise since I often fish near docks early mornings and late evenings. Open exhaust, no can, over-hub props, and 6,000 rpm holeshots are not my thing. I run a 26 Trophy 4 blade on the Allison/Promax SS so I can sneak away from docks and plan to do the same on this 2.0L when I finally get it built and find a boat that I want to put it on.

That is a 2.4 Bridgeport exhaust tuner # 41941 coming directly from the pages of Bass & Walleye Boats Magazine "Hot Rodding the Mercury 150 V6" October 1998 issue article. I found it on eBay, beadblasted it, and painted with Epoxy coating. Gordon

451371451372
So I need to get one of those tuners as well?

[Merc 2.5]

What were they wh?
The shorter the tuner the worse bottom end. Shorter better top. Supposedly but dont get a tuner thing goin. 90% people say waste money and time. Unless u have a 3ft tuner (which u mite)

[Gordon02]

The article is from 1998 and has dyno charts included where they test each of 3 different add-ons and show how they took a stock 150 to 183 horsepower with bolt-ons. Reeds, Tuner, and Brucato SVS added performance in every step. The Reeds made the smallest increase, but made the idle and acceleration a lot smoother. The Tuner allowed higher rpm and allowed the engine to breath up-top and took hp to 171 or so. Since we're both using carbs, the results with the SVS won't matter. Now, the caution I've received is that low-end torque will suffer with the shorter tuner and will only really "shine" at high rpm on light, fast boats. Gordon

[Merc 2.5]

The article is from 1998 and has dyno charts included where they test each of 3 different add-ons and show how they took a stock 150 to 183 horsepower with bolt-ons. Reeds, Tuner, and Brucato SVS added performance in every step. The Reeds made the smallest increase, but made the idle and acceleration a lot smoother. The Tuner allowed higher rpm and allowed the engine to breath up-top and took hp to 171 or so. Since we're both using carbs, the results with the SVS won't matter. Now, the caution I've received is that low-end torque will suffer with the shorter tuner and will only really "shine" at high rpm on light, fast boats. Gordon

Ya I agree but most of that gain would come from Svs I would think. If u swap long for short bottom suffer a little but not that much, if u can vent ur prop little more mite not even notice a difference? 150 has a very restrictive tuner tho. Find u a 2.4 bell tuner or Bob's

With that said if u get compression up u won't have any loss , but if u do all mods at once, u wont know what did what but ea mods will work coinside with other mods. if makes any sense

[Merc 2.5]

Get ya 2.4 200 front half (horizontal) 4pedal reeds , cut heads ,drilled mid ,bell tuner, wh22 or 46 jetted accordingly, 16amp charge system, possibly smooth exhaust chest out, run 93 fuel. Really like the 2.0. they can take a beating

[Gordon02]

The reference to SVS is only because the tests were done on an EFI. We can get the same gains and numbers with properly jetted carbs as long as they aren't those small 1" throated ones. I've read that the Mercury Bridgeport tuner does out-perform the aftermarket ones from Bob's and perhaps Land and Sea (I can't remember exactly). Again, this is yet not-proven as I'm still building. A Glastron GT150 / Evinrude 115 V4 fell in my lap, so a full restore and build-out to 140 horses will come first before I can get back on my 2.0L. Gordon

[TNRoostertail]

Ok so here is where I'm at as I want to keep it simple.
-26-28 cc heads
Performance reeds (which ones?)
Drilled mid
2.4 tuner
This will be on a norris craft 1700 super v pro medalist which is a pretty light boat.

[Capt.Insane-o]

26 cc on the heads
200 tuner
CCMS or TDR reeds...boysens suck.
WH 39 or 46 carbs..the stock jetting will be close
Solid mounts of course and while your that far a fat tiller shaft from a newer motor. The life you save may be your own. They will pull okay to 6800 on a light boat.

[TNRoostertail]

I just found a 2.4 200 tuner local. Trying to buy it now. Is the fat shaft just a thicker drive shaft? Or will it require different yoke setup at the lower and engine?

[TNRoostertail]

What will be a safe rpm level for my setup, as in longevity? I'm not a drag racer like you guys lol. I would like to see 6200-6400 though if safe.

[Gordon02]

I've got the big carbs, I have opened and smoothed my chest, so yes - I plan on mine making good power at 5,500 + and I do plan to turn it 6,200 ~ 6,400 when at full play. I'm not a WOT guy, but this motor is for whatever I want it to do. I'm having my pistons top-pinned and will use brand-new rod cap bolts to factory specs. Not sure what it's going on yet. I thought I wanted it for the GT150 I'd build one day, but now that I have the boat - I realize the limits of this hull to handle that level of performance. The V4 and 140 hp crossflow I'm building will be all that I can handle. With no pad, it needs to stay below 60. Gordon

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[Merc 2.5]

I just found a 2.4 200 tuner local. Trying to buy it now. Is the fat shaft just a thicker drive shaft? Or will it require different yoke setup at the lower and engine?

Make sure it's the bell tuner , it will have a flare at the end

[Merc 2.5]

Fat shaft had 19 splines I think. Small 15. wouldnt worry bout lower if it's ok, 6200 6400 fine but if u get it down to 6k u will have good bottom and top , it's a good balance point for blast off and top speed

[Gordon02]

The article was specific - Mercury part# 41941C - here is a side view. This is quite short at approx 7" in total length
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[Merc 2.5]

Sry Gordon. didnt read article

[Gordon02]

Oh yea, those solid mounts are sweet. These came from Bob's. I had the Land and Sea mounts on my Johnson GT150/Allison and then this SS ProMax came solid too. Love them.

Here are the ones just installed on the 2.0L build -

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[TNRoostertail]

Thanks for the good info guys. What heads can I look for exactly? Will 2.5 heads work or just the 2.0 heads? Thanks

[tnelsmn]

I just found a 2.4 200 tuner local. Trying to buy it now. Is the fat shaft just a thicker drive shaft? Or will it require different yoke setup at the lower and engine?

Capt is referencing the tiller arm on the mid. Not the prop shaft. Heres a new style "fat" tiller and an older "skinny"

[TNRoostertail]

Is that pressed on? I would prefer the fat arm. The one on my buddies pro max is much beefier like the one on the left.

[tnelsmn]

I believe its the entire swivel pin that would need to be changed, not just the tiller are itself.

[Dave S]

and the fat one is from a 3 ram...... the fat ones from a 1 ram are hard to find......the thin ones are fine for boats not flying on the prop shaft.....