CSPEC Help

[flyinrazrback]

Got a question for you cspec gurus. My OS 91 cspec ran flawlessly for me in the following configuration. I was running the stock head, stock shim, enya #3, hatori SB-18, CY 30% fuel. Cat eye mod and optional 3rd needle. Was running one line to the main tank for muffler pressure, the return line directly to the main tank, and main tank line to the header tank, to the pump, to the carb. Running ~1.25 -1.5 on the high needle, 1.5 on the mid needle, and about 10 o'clock to 11 o'clock on the low needle. 5 gallons total through the motor. No problems. Since then I have sold the motor and he is having problems getting it to run right. He is running the stock head with extra shim (Magnum 30%), same fuel setup as mine, Hatori SB-17, and enya #3. He can not get the motor rich enough (running very lean), running like 2.5 turns on the high, about 1.5 on the mid, and full rich on the bottom. He has even bypassed the pump and cannot get it rich enough. Any ideas? I do not have a problem giving a refund for the motor, however the motor ran perfect for me when I pulled it out of my heli. Any ideas

[flyinrazrback]

problem solved, will try to explain it best I can. Apparently the nipple on the muffler was bottoming out in the muffler and getting no pressure at all to the fuel tank, and the cspec pump was sucking with no muffler pressure. Fixed the nipple so it didnt bottom out, and problem went away and running fine

[Gary O]

Since I'm just about to throw my hands up on OS motors period, I would like ot get a little more info on what you mean by "bottoming out". Without doing an exact count, I know of 6 of my MA machines with C-Specs in them and I don't like any of them. I have 4 others with YS 91's and they run flawless. If I can't figure this out soon, I won't ever own another OS engine. What you are describing in this situation sounds a lot like what I'm having in mine. ONe minute I'll have a good tune and the next it's lean as hell and crackling like popcorn. I've tried everything I know, pump pressure, no pump, needle settings, I just can't get em right.

[DavidH]

Gary,
Basically he is saying the pressure tap and nipple on the muffler was not allowing enough air to pass thru it. This would cause a vaccum on the tank with the PS motor and cause it to run lean. The reason being the pump could not pump enough fuel from the tank due to the restriction on the line from the muffler.

I don't know what type of problems your having with OS Cspec motor. But the ones I see seem to run flawless. I have two C specs with Cline setups. They run great and have mucho power. I am very happy with them.

David

[Gary O]

I've only got one C-Spec with the cline set up on it. It is on a Stratus that I bought from Will a couple months ago. I flew it Sunday and it's got a fuel leak somewhere around the reg. That motor runs great but all my other S-Specs are so inconsistent you can't even run em a full tank without having to make needle adjustments. It's rediculous. They are all in MA helicopters but I'm running Hatori pipes, MP2's, nothing makes a difference. It's tough to stick with a motor that is that hard to keep tuned when my YS's just crank and go and run perfect from flight to flight without a tweak on needle settings. Now I will say, that the 2 I have with the new SZ's in them are fine. It's just the C-Specs.

[WillJames]

Check and make sure the Elbow is secure to the regulator Gary. Better yet, take off the elbow and attach your tubing directly to the nipple on the Cline. THe only place it could really leak is at the union of the elbow to the rebulator, unless the screws worked loose in teh regulator, which I have not seen or heard of.

That motor is the FULL OMI BB/Cline basically every mod James does except the secret ones. ;)

Glad to hear it is still running great, it sure ran good for me. No fule leak though, I bet the elbow has come loose. Sorry to hear you are having trouble with your OS Engines. You need Dr. C-SPEC Clinstone Akins to help you, he can tune any OS, so can Harkey.

[Gary O]

Will,

I got home yesterday afternoon and took the elbow off the reg and that's what was causing the leak. I got 4 flights in before it got dark and it's fine. I guess I'm going to have to send all of my C-Specs to James if I want to get any use out of them.

[WillJames]

Thanks for the feedback, I am glad I could help. That Cline setup is so simple, gotta love that!!

I am very happy you are enjoying the Heli.