Taking a second look at omc

I have been a mercury fan for as long as I can remember. I have owned many different mercury motors and have been very loyal to the brand. I do have a few favorite OMC's. Like a 3 cylinder 75 or a small 9.9/15 But mercury has always been my favorite v-6 With the price of used mercury racing outboard's ( stupid crazy prices and I understand about free market ) or mercury outboard's in general and the price of genuine mercury parts or used parts it's making me take a second look at OMC. I have to be honest also with Mercury being so dominant on here for so many years it's almost becoming boring. So interested to take a second look at OMC and start trying to figure out how they run. I look at Mr. Bush and Monty and see what they're doing with the OMC's nowadays and it's very very interesting. Has anybody been thinking like this also or in the same way? Just asking for a conversation

I think I enjoy working on boats and motors more than I do actually going out in a boat.. I know that's kind of backwards but each his own.������

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Originally Posted by 30velocity

I think I enjoy working on boats and motors more than I do actually going out in a boat.. I know that's kind of backwards but each his own.������

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My wife tells me that all the time.

Ok. So a confession. My first memory of loving boats goes back to pre-kindergarten. I remember we had a day with building blocks and I built a big houseboat. all the other kids went out to play on the playground but I was obsessed with building this house boat. I have vivid memories of being in the fourth grade drawing pictures of checkmate boats with inline 6 on back in math class. I went to vocational school in Sarasota with for marine mechanics. Although I'm not a mechanic by profession I certainly enjoy working on them. I usually spend an hour or two ( ok more) either in my mind or online thinking about boats and motors. I think maybe this is a little bit unhealthy but it certainly makes me very happy

SS minnow. Thank you. I do like that 140 looper motor I think there's even more horsepower hidden behind it. They do run good. Thank you again

Hell yeah, I say do it. My favorites are the gold rudes from the 70s....to me they sound the coolest and are pretty simple. So build one up!

I had a crossflow v4 since new in 83 and it never skipped a beat. They run strong and go great as a stock motor and they are light. They are a less efficient system than a looper so they drink more fuel. I’ve never owned a looper omc but there are some Mighty fast ones out there.

this whole high perf boat hobby is all about fun times. Do what you find fun and your winning at life right there. As above I enjoy the build as much or more than the driving. I also enjoy staring at well built things and beautiful curves and lines. Hydro streams win my admiration a lot in this regard. Gorgeous design

Our family ski boat had a 150 HO Etec. Very good on gas, much easier to maintain then an Optimax. My SS2000 has the unicorn Gen II 200XS ROS. Stock Evinrudes didn’t have the equivalent of a sportmaster. Much as I love the Etec, I bought the Mercury to go fast

Great bang for the buck and bonus points for being different.

95% of the OMC complaints on here are about motors worked on/repaired by non OMC people.
Starts hard, won’t idle, bogs etc.
Their six one barrel carbs must be synch’d to run properly.

A non OMC guy tries advancing throttle position to cure this snd that is the last thing to do.

Based on that, not the motors fault.

Or, misses and won’t rev.
But the current owner “knows” it’s not due to the orig/30 yr old powerpack!

Or, a V-6 looper won’t run w/a hot rod 2.5.

Really?
How about a fishing version 2.5/3.0?
Totally different outcome.

When we lived in Fla, I bought every blown up V-6 looper I could find.
$500 - $1k dependent on condition and completion.

Of those, 90% had been rebuilt previously.
Of them, 90% were done poorly.
Many that didn’t even run long enough to color the piston tops!

Again, not the motors fault.

So, how about the good?

As already mentioned, they’re dirt cheap to buy, and repair/hot rod if you can do your own work.

As compared to a hot rod 2.5 w/plated bores/cylinders, OMCs are steel sleeved.
So if/when you stick one, muratic acid will take the piston goo off the bores, then it’s ready to hone.

If the bore has severe damage, you can buy a new sleeve for a $100, chunk the block in your barbecue grill at 425* for 45 mins and swap sleeves.
(your wife’s oven works well too but you will be punished by her and your house will stink for days!)

The comment about gear cases is correct.
If you like to tinker (why else would you attemp to hot rod an OMC?), they can be made to work.If you threw bolt the prop shaft carrier to the housing theyre near bullet proof.
Add a nose cone and now you can Jack it to the moon.
Ive done several that I added 50%+ surface area material to the skeg, which then allows you to install the taller torque tab that won’t fit a stock one.

The OEM porting is very conservative but on a light hull you can still get one to run.

Yrs ago I bought an STV River Rocket w/a box stock 1994’ 225 looper that turned a 29” SRX 7200 Rs every time out!

That motor ran the VRO oil injection, air box, closed exhaust etc!

As I was building a serious looper for that hull, I used that orig motor as a test mule.

I tried everything you shouldn’t do but always wanted to try.
It becomes way more fun on a motor you care nothing for!

I bolted on the best OMC heads, intakes, carbs, opened the exhaust (raised the exhaust ports while swapping heads, by shoving a shop vac hose in the exhaust snout), it already had a nose cone and then jetted it accordingly.

All w/o splitting the cases!

I never finished tuning it for top end but did get it to turn a 30” RE3 7400 and a 22” drag prop 8300!

That motor was an absolute blast and shocked many, many people.

If you like to tinker and have a strong level of patience….., why not?

One of my favorite hot rod OMC stories was with my first serious attempt at a hot rod looper which I called FrankenRude I.

Was at the ramp just getting ready to launch when a guy came walking up to check it out.
He didn’t know that I knew him and that he had a hot rod 2.5 Merc on an STV That you could see on the other side of the harbor.

His Final snide remark was that he had never seen a fast Evinrude.
I pointed at his boat and asked if it was his and when he confirmed that it was I suggested he go get it and then I would wait for him.

He did not ��

Thank you for all the great responses and I'm glad to see nobody was saying mercury is better than OMC or vice versa. It's nice to have a conversation about just outboards. As stated I've had many different ones but I look forward to putting something together in the future. I'm sure I'll have many questions. Thank you again. So has anybody looked at some of Bush's omc's? I saw one the other day that I swear I look like a piece of artwork. And there's been some recent videos of OMC's running and you can really hear them turning some rpm'

Definitely go for it like they already said there can be plenty to find depending on where you are, prices arent as crazy and easy to work on even if you want to do some modifing?
Where i was i found lots of fresh water motors made things so easy too.. after i moved (desert)am thinking renting a trailer to go back and get some not as plentiful around here, but have enough for now

Hey Gator, any updates on your Checkmate or have I missed them??

I got a Hydrostream Vamp for a shallow water fishing boat I'm going to install a 11 inch pad move the transom back 12 or so inches and want a light motor of 140hp or less, I don't care who makes It, I know the crossflows were light but would rather have a looper, just something about going back to cross-flows that I have Issues with, what ever I use It will become a 15".

I always ran johnrudes on my small fish boats. They all were great engines. The 140 on a 17 whaler was my favorite.

Still thrashing.

Still fighting intermittent running issues w/port motor.


At least I got it to idle/shift around dock so I’m not tearing stuff up getting into dock, anymore.

Still tons of small projects but free time is scarce.
Taking a break accordingly.

Functioning kill switches are top of list.

I guess I need to be happy w/progress made.

Similar to basis of this thread, I started w/4 motors, and $3k later, I have 2 complete, including new pant/stickers, a new LH gear case and enough parts to build two more.

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Originally Posted by 1954bmw

Hey Gator, any updates on your Checkmate or have I missed them??

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