2.5 Mercury build

[wired247]

Re: 2.5 Mercury build

I just got back from the machinist. I thought he was going to b**** slap me. We went through the bores. they were perfect. There was one scratch on one of the cylinders. He said why are you worrying about that.? the porting on this thing is beautiful and that scratch is minor, don't touch it. Second opinion duly noted. I will leave it alone.

 

[bajaunderground]

Re: 2.5 Mercury build

Good eye. 1981 Checkmate Enticer. My dad bought it new in 1981 the same week I got my drivers license and Ive been dragging that boat around for 32 years. I gutted it and put a beefier transom and all new interior wood and upholstery a couple of years ago. New everything else too come to think of it.

That motor looks Monsterous on that transom...! I love me some checkmates...

 

[Faztbullet]

Re: 2.5 Mercury build

Lemme ask u this Wired. You may have chimed in on my post on the other board. I don't remember if u did. How do you feel about balancing the rotatig assembly and going with a light weight flywheel. I feel like it will be a plus others say don't o the flywheel.

My opinion on lite flywheels is they just help acceleration (lighter mass spins up faster), never seen one add HP in my days of racing.....

 

[wired247]

Re: 2.5 Mercury build

I picked up 300 RPM when I installed the 16 amp system on my 2.0 last month. One day it never went above 6700 with a 17 pitch prop . Took the 40 amp system off and installed the 16 amp tand he next day it ran 7000 whenever I pushed the throttle down all the way and kept doing that whenever I pushed the throttle down all the way until I tore it apart 2 weeks ago. No other changes.

 

[1FASTLASER]

Re: 2.5 Mercury build

My opinion on lite flywheels is they just help acceleration (lighter mass spins up faster), never seen one add HP in my days of racing.....

Bingo.... My point exactly. It doesn't add hp but what you have hp wise can now spin up faster. And that will add to performance.

 

[Dukedog]

Re: 2.5 Mercury build

Just a little something ta chew on 'bout the lite flywheel. Do ya know tha "real" reason for its development. Here's a hint. It wasn't "for acceleration or bearing stress"!.............

 

[wired247]

Re: 2.5 Mercury build

Parts keep rolling in. Heads came in from Rucks machine today. Had them cut the chambers to 35 CC. I don't expect much more than 135-140 lbs cranking compression with this one. With premium unleaded that should let me run 25 degrees total timing advance. I could have gone with more like a 32 CC chamber and been in the 145-150 lb range but most I could have run is 22-23 degrees timing. Personally, I think engines respond better to a little more spark lead at the expense of cranking compression for a given fuel.

FWIW if you ever want to get your heads cut Rucks does them cheaper than anyone. $55 for the pair.

 

[1FASTLASER]

Re: 2.5 Mercury build

Just a little something ta chew on 'bout the lite flywheel. Do ya know tha "real" reason for its development. Here's a hint. It wasn't "for acceleration or bearing stress"!.............

Enlighten us!!

 

[Dukedog]

Re: 2.5 Mercury build

Slowin' down.................

 

[1FASTLASER]

Re: 2.5 Mercury build

Who wants to do that lol!!! But I now what u are saying

 

[Dukedog]

Re: 2.5 Mercury build

$55 for the pair................Daymn! Haven't seen that price in 20 yrs...

 

[1FASTLASER]

Re: 2.5 Mercury build

Correct me if I am wrong Wired. Could u not got to 32cc and still be good on 93 octane real gas that is..not that ethanol crap.

 

[wired247]

Re: 2.5 Mercury build

Correct me if I am wrong Wired. Could u not got to 32cc and still be good on 93 octane real gas that is..not that ethanol crap.

You might be able to but I can't get 93 real gas here . Best I can do is 92 ethanol gas or 91 non ethanol . Thats going to be 35 CC at 25 degrees which I prefer or 23 degrees at 32 CC.

 

[1FASTLASER]

Re: 2.5 Mercury build

What happened wired? Did ya hit a bump in the road on this build?

 

[wired247]

Re: 2.5 Mercury build

Ive been working on the bobs nose cone all this week. How Bobs make any money doing those for $450 installed is beyond me. The powerhead is all together except for the carbs which I am waiting on. Should fire it up next weekend. I will put up pics later this week of the entire build.

 

[Faztbullet]

Re: 2.5 Mercury build

I myself when "hot rodding" had several customers and myself loose a Bobs cone due to epoxy came loose. Had more success/speed/lift/water pressure with the Hrdromotive cones. You can run these higher than a Bobs...

 

[wired247]

Re: 2.5 Mercury build

I myself when "hot rodding" had several customers and myself loose a Bobs cone due to epoxy came loose. Had more success/speed/lift/water pressure with the Hrdromotive cones. You can run these higher than a Bobs...

If that one comes loose its going to be quite a trick. It was full perimeter welded with a spool gun off a Miller 212 power source and pressure tested after welding before I started using any filler. Probably 2/3 lb of weld wire holding that on there. The skeg torque tab was also built of weld material and sculpted to shape. The epoxy was only used to fill the low spots between the cone and the main housing.

Thats a dual pickup big foot cone. Holes only on the bottom. I dont see how you could get any higher than with that .Hoses on both sides. The Bobs hoses and hardware are a joke though. I probably spent more buying real -10 AN hoses and fittings than i did on the Bobs cone.

I cannot see running one that was simply glued on.

 

[wired247]

Re: 2.5 Mercury build

Turned the key today and it fired right up so I'm feeling pretty good. Ive got a few other things to take care of this week so I wont get into final tuning until this weekend.

We'll start with the carbs. Remember this is a 2.0/150 that I'm turning into a hot rodded 2.5 so I'm using the original 2.0/150 carbs. Ive seen all kinds of advice about carbs over the years. Usually its more along the lines of "I want more power out of my 150" and the answer invariably is "put 200 carbs on it" . Dumb, bad advice. 200 carbs as is are jetted WAY too fat for a 150 not only on the main jets but also the air bleeds are all wrong. Sure the venturi MIGHT be bigger but that doesnt mean they will work worth a flip. In my case I am using 2.0/150 carbs on a hyperactive 200+ HP 2.5 . I can do this because I am using WMV-2 carbs. They are standard issue 150/105 HP jet carbs for 1996 and use the same castings as the 200 HP WMV-5's for that year . I duplicated the 200 HP main jetting and idle air bleeds and removed the back drag jets to fatten up the mid range/cruise. That's a starting point but it should be pretty close.

During this build I used very few specialized tools. For a normal engine rebuild where you aren't trying to diagnose or fix any problems there arent really any specialized tools needed to rebuild a Mercury V6. Sure you need a torque wrench and maybe a flywheel remover tool but those are cheap. One thing that I think is invaluable for Mercury work though is a zip tie tool with a pack of the proper tubing zip ties.

I use a paladin tools McMaster-Carr

Along with the zip ties McMaster-Carr

 

[canoemang]

Re: 2.5 Mercury build

This build posted over at scream n fly?

 

[wired247]

Re: 2.5 Mercury build

Nope.