Well, the O-200 crank STC is NOT about changing your engine to a O-200 engine with that performance. Even though the crank gives you more torque, it should all stay within the 85 hp (well maybe up to 90). I doubt that you could find a Stromberg carburetor description for a O-200. These engines were fitted with the Marvel -Schebler originally and do have a bigger ventury too I assume. They are also designed for engine speeds of around 2700 rpm unlike our C-85s with their 2575 max. rpm. The Strombergs had been used up to the C-90, which comes very close to a C-85 engine with the O-200 crank Stc. Changes to the carburetor for the C-90 had been a one number bigger main metering jet and a bigger main air bleed. These changes affect the engines high power output but do nothing to the idle circuit of the carburetor. As I understand the problem here is not enough power, but smooth engine operation. I would not be that fast on jumping to conclusions. Before changing jets I rather recommend swapping carburetors with a known good one and see if the problem disappears. There are many other sources for a lean mixture. Like loose or over tightened clamps on the intake hoses, leaking gaskets on the intake flanges on the cylinders. This by the way is more common than you think. When installing the exhaust system on our Coupes one has to remove the intake elbows on 2 cylinders, otherwise you can't fit the exhaust. Reattaching them is a real pain. If not done right, you have an intake leak there. Ok. I am off the soap box. Hartmut
To: [EMAIL PROTECTED]: [EMAIL PROTECTED]: Tue, 9 Dec 2008 00:10:36 +0000Subject: [ercoupe-tech] Re: Several Questions. The C-85's that have the 0-200 crank STC have a very common problem of running lean. We had a j-3 with this problem. It ran fine with a certain carb on it. When it was nosed over it was broken. We had a spare one, my boss said that they had tried the spare before and it didn't run. I took the two of them apart to see the difference between them. It was the jets. Which makes sence. I swaped the jets and it worked fine. One other thing, when you convert a C-75 to C-85 there is a jet change. When you do the stc may be there should be a change too. I have a parts manual for the stromberg, I'll see if I can find jets for a 0-200. Mark--- In [email protected], Bob Stearns <[EMAIL PROTECTED]> wrote:>> I was just (coincidentally) thinking of posting a reverse carb> problem. Mine is that the engine runs fine below say, 60F but often> fails to idle below 1,000 at temps in the 80's and 90's. In fact the> engine has stalled while taxiing during the summer. A short prime and> I'm off and running. FYI, central South Carolina. > > Everything> else about our two planes is pretty much the same. C85 with O200 STC> and I assume, a Stromberg carb. Both of our problems must be of a> piece. So, I'm watching this space, anticipating an answer I can use.> _________________________________________________________________ Suspicious message? There’s an alert for that. http://windowslive.com/Explore/hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_broad2_122008
