Captcrunch44

did you ever get your ops running? c-crunch

victimofthegame

My buddy and I got a new gasket made for the carb/engine mount...thought it was tore. It didn't make a difference, but then all of a sudden the thing wanted to run great. Got it setup good and the engine just plain run. Then I took it to the field and ..... it ran like crap again.....it would die as soon as throttle was advanced....I am about done with the thing.

davemilw07

Sorry to hear about the problems-------doesn't make much sense, does it?????

It sure sounds like a strange carb problem of some sort, since the mechanical parts of the engine do not (and can not) change.

If something was clogged up in the crankcase pressure line going into the carb base (dirt, gunked up castor oil, etc.) it could cause carburetion problems, since the pump diaphram wouldn't work correctly. You could try running a thin wire through the passage way, to clean it out (maybe some disassembly will be required).

Did you have any luck trying to get ahold of Tillotson??????

Regards, Dave

Captcrunch44

i was afrade you would give up, alot of people do. theres only two people i know who could ever get them running. me and bob from LHS who sold it to me. every one around here has hooked them too there boats. ha ha. i guss i have been lucky. c-crunch

BobbyGee

My Feedback: (3)

Reviving an older thread here, but I have one of these engines with a Dell-Orto and I want to get it set right. Here's hoping c-crunch sees this and can contribute:

I started it for the first time the other day and it started just fine. Prime, backflip and it goes.

A few times it started backwards, but that seemed no problem. I just let it die and started it again.

I got it running and was seeing how well it transitioned when I heard a cracking sound. It turned out to be the Woodruff Key on the prop shaft. I've since located a replacement - an adventure in itself. I need to know more before I go back ouy and try to bumble around not really knowing what I'm doing.

My question is twofold:

1.- Which needle is the high speed needle, and which the low? What are good initial settings for them?

2.- What could have caused the backfire strong enough to pop the Woodruff Key?

I'm using PowerMaster fuel custom blended for me, 5% castor, 95% methanol, no nitro. Plug is a McCoy MC-4.

Thanks for whatever help you can provide.

BobbyG

Mcubed

Sad to see no reply. I have two of these still unrun in boxes,and was waiting to see if the forum took off again I suspect that it will not.

Flyer95

My Feedback: (1)

I hade the OPS MAXI 60cc twin for some years. It did not had the original Del-Orto carb. but had an homemade slide carb. with a separate Mikoni pump. It was ok on power, a little stronger than the STG4500 which it replaced but it dropped a cylinder sometimes in the air and caused me to land.
Important is to use the correct fuel which is maximum of 5%oil and methanol for the rest. I only benchran my 30cc:s with tuned pipe and the original Del-Orto carb. for a short time and it seemed like they had great torque easily turning an APC 20x12 prop.
If the Del-Orto carb is not working well, and difficult to find parts then i think another 90-120 carb. can be fitted to these engines.

Cyberwolf

My Feedback: (4)

I sold my Maxi 30 to a fellow but all the instructs was still in the box as it was bench ran only then sold. All the carb settings was in the instruction book as I recall. I never really had the correct fuel for it, but it ran fairly good on the bench for me even with the nitro in the fuel and way to much oil. If needed he still has the engine in the box I can get the correct settings if you wish and post them back here. BTW those engine's were ment to be used with a pipe of some kind if my memory serves me right. After reading the OP thread it makes me wonder just what they had for a muffler, maybe something that was choking it down to much, that would create the conditions he was having I do believe.

450strmn

I have a OPS Maxi TWIN that I've run on my scratch built 25% Stearman.  It's a jewel!  I converted it to gasoline and put a CH ignition on it running the little rim fire plugs and fully shielded ignition wires.  Turns a 22X10 prop and I run a walbro carb on it that I use on the stock intake reed assembly.  I use a scratch built muffler

Cyberwolf

My Feedback: (4)

Well I wound up getting the 30 maxi back along with some other items, so the first chance I get I will also be converting it to a gas engine. I checked the crank and rod and there already needle bearing both ends so a carb change it should be set to go.

Break it Bill

I have an OPS 60 and it was doing some of the similar things. I kept messing with the fuel mixture and so forth getting no where. Than I remembered an old OS that was doing the same kind of thing and te problem with that motor was the cylinder lining coming off. So I went to take the head off the OPS to check the cylinder and the head bolts were loose. Checked the cylinder anyways then and it was good so I put it back together and the engine runs like a top now. The moral of the story is, If it acts like fuel but theres nothing wrong with the fuel check something else.