trstein

I'm in the middle of breaking in a new FT300 to be installed in a GP Christen Eagle. The engine sounds really great, but with the straight headers, it's pretty loud. Awhile back I saw a reply you posted to another members question that you could put put the can for an OS FS120 onto the FT300 flexible exhaust pipe. Couple questions:

1) would the can for the FS120 screw directly onto the threads for the FT300 flexible pipe or does it require an adaptor?
2) with one FS120 can on each cylinder, is there any performance issues to be considered (would it reduce, enhance, or do nothing to engine performance)?
3) besides needing to support the cans in the cowl, are there any issues you can think of (pros or cons) with putting mufflers on the FT300.

Hey, as long as I'm here, I have one other quick question. I have heard a fairly wide range of opinions on how often to check the valve clearance on the FT300. One guy states that he checks his once a week. I'm pretty new to 4 stokes and this is my first twin, so any advice would be appreciated. Thanks................

Bax

My Feedback: (11)

The muffler body should screw right onto the flex pipe. The main thing about the flex pipes is that they not be allowed to move around. They may have to be supported 1/2-way between the cylinder and the muffler body. The muffler body should have a point of support at each end so that it doesn't pivot a bit. Don't put much of a bend in the flex pipes, especially near the engine. O.S. states that 1/2" radius is the minimum, but we'd suggest more, if possible.

Rocker arm to valve clearances should be checked after the first 2-4 hours of running, and then only when needed. If they get noisy or performance starts to drop. If the engine's run normally, you should need to check them only once or twice a flying season.

trstein

Bax, due to the length of the FT300, the engine sits closer to the front of the cowl in the GP Christen Eagle than would the other recommended engines. Therefore in order to keep the exhaust header inside the cowl for the forward most cylinder, it requires a tighter bend than OS recommends for the flex pipes. Do you know if the OS Exhaust Manifold Inside which is sold for the FS-120S will fit on the FT-300? This would enable me to make a tight header bend right out of the engine, screw on a short flex pipe (which could stay virtually straight), and then hook into the FS120 muffler can. I'm just not sure how interchangeable the manifold and flex pipes are since OS has different flex pipes and headers for the FS-120 and the FT-300. Also, does it matter which muffler can I use on the FT-300 (FS-120 or FS-120 Surpass)? Not sure if threads are standard or if there is a difference in the cans that would affect the FT-300 performance?

One last question - will mufflers on the FT-300 have any performance issues?

Sorry for all the questions, but your guidance is very much appreciated!