Merco .61?

Any of you guys out there have any experience with one of these hummers? As you can see, it's old technology, single bypass. It has two rings. It's pretty light, 11.4 oz. without venturi and NVA. This one is in great shape. It's maybe been run. I think maybe someone just attempted to get it to run as it looks like it doesn't have any time and the spraybar hole in the carb was pointing straight up. Is it worth getting a venturi and NVA for? What would be a good venturi size, using a ST NVA?

Thanks,

John Wright is the acknowledged Merco Expert. He also happens to be a person I respect and admire very highly. Hi John.

"I don't know about this tuned pipe business. I practiced on that thing until my lips turned blue, and I still can't play a stinkin note."
"Homer J. Simpson"

>Any of you guys out there have any experience with one of
>these hummers?

I have a little bit of experience with these but I believe John Wright has much more. I hope he checks in on your post.

>Is it worth getting a venturi and NVA for? What would be a good
>venturi size, using a ST NVA?

Yes, in my opinion it is definitely worth the trouble! I run anywhere from .295 to .310 with ST NVA depending on the airplane and other related stuff. I got very good results from my later model .61 with moderately tall .310 and air filter with the black mesh screen.

I like the big old Mercos a lot. Perhaps you will too.

Thanks for the feedback guys, and maybe John will check in with some further advice.

The old motor just looks like a good candidate to me. I'd love to use it (got it real cheeeep too!).

Listen to Dave. His ran really well. Best "sounding" stunt engine I've ever heard.

Got to reply to this!!! Congratulations, you have a great light case (Mk.1 or maybe 2) Merco 61. Power will not be enormous, but it should give a great stunt run. Such a pity the case was enlarged to give more weight to satisfy the radio boys. This engine has the same mounting holes as the ST 60. For Merco history as far as we've written it, see Dave Day's site www.iroquois.free-online.co.uk under Merco.

Thanks for the vote of confidence guys. Yes this Merco is worth getting a venturi. The nice thing about this Merco is that it fits the ST 60 mounts. You may need a 1/8 extension on the thrust washer to match the ST length. A .290 -.300 venturi and a 12-6 or 13-6 is a good starting point. It has good low end power and an excellent stunt run. No modifications needed. Enjoy

Thanks Ian and John. You've made me feel as though I've made a good purchase for once. I'll look forward to using it. You say the power won't be "enormous". How will it compare to a Super Tiger .60?

I'm stashing stuff up until I can retire. I have two Magnum kits. I've got new Tiger .51's for both, but now I'm thinking to use the Merco in one. I'll make a venturi at about .300"

Your saving stuff for your retirement too? My garage is full, I can't even get in anymore.
The Merco, in its stock form, has enough power for a Sig Magnum size airplane, at about 65oz. But it won't run the rpm that a ST will. I would go no more than 8500 for best results. It can go almost to 9000 rpm with a smaller prop. It should pull a 13-6 up to 8500 rpm, enough to pull anything. I usually run no more than 10% nitro, but you can always run more. I've used up to 15% with good results.
A word of caution that I got from Frank Williams. I experienced flame outs a few years ago. The cause: too much oil. I was using 24% and Frank said that Merco's run so cool that they can flame out. I'm running 20% oil now and I have run 18% stock Powermaster with good results. No more flame outs.
If you want even more power, you can open the round hole in the crankcase at the venturi to a rectangle via hand file. You have to take the bearings out or risk metal filings in them. But don't change the crank timing by filing past dimensions of the original hole.
Another trick is to find a heavy case Merco with a steel fin sleeve. It should have a dykes ring piston. Swap the dykes ring piston with the double ring piston in your light engine. The dykes ring piston should boost the power a little.
That's about it. Happy Landings

Just realised I made a mistake in message No.5. I should have said the ST60 fits the same holes as the Merco!!!!!!!

>
>I'm stashing stuff up until I can retire. I have two Magnum
>kits. I've got new Tiger .51's for both, but now I'm
>thinking to use the Merco in one.
>
>Herman Green

I'm doing the same thing, stashing up sets of kits, engines and accessories that I've matched up in my mind for the time when I can settle into building and flying.

I've got two CLC Super Chief kits which I intend to build up as a matched set with similar markings. One will get a Merco .61 twin plug and the other will get a Layster ST .60.

Everyone says the big Merco sounds great.

Cy.