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Old 03-12-2007, 06:13 AM
  #93  
rc34074
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Default RE: SuperTigre mid-range problems?

I have 6 g90s. they are up to 9 years old. They all run very well. I have 3 chinese built 2300s. I have run two of them, and they run even better than the g90s. In fact they tune/run better than the OS61sf, which up to the time I bought the first 2300 was the best tuning engine I had had.
If you expect them to tune like you want them to tune or as you would design them it's not likely to happen. They are a very good design. You need to learn how to tune them. They do not tune like a Saito. Saitos run extremely rich- at least the ones do that the Saito guys at my field run. Tigers do not. Tigers run well a little rich but nowhere near as rich as Saitos.

Proper back pressure from the muffler makes the tigers tune and run best. They do not take a low idle until they are broken in well, as the ring isn't seated against the cylinder well enough to pull fuel well until they are broken in. So you need to either run them with an high idle at first or break them in well on the ground. Then you can tune them in for a low idle - low being 2k- 2.5k rpm, at least for the props I tend to use. I use apc 14-6 on the g90 and 17-8 wood props on the 2300 (I haven't picked a preferred wood prop source yet- still deciding).

Bisson and Slimline seem to make mufflers that physically fit the engines they make them for, but they don't seem to do any real development of the muffler to make it a proper design for the engines. So in my opinion it's not Super Tiger that has an improper deisgn, its Bisson and Slimline.

So why hassle Super Tiger? Why not get Bisson and Slimline to fix their pitts muffler designs? This would cure most of the problems people have. Or maybe look for another muffler source that has done their job properly.

As for me I have found the easiest way to fix their mufflers is to close down the outlet tubes until they provide enough back pressure so the carb tunes correctly. This is especially important on the 2300 mufflers, which have outlet tubes that are WAY too big for the 2300. It also helps on the g90 - they are fairly good as Bisson and Slimline make them.

So this thread more properly should be labeled Muffler Design Problems, not Super Tigre mid-range problems.

Ed