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Hello all,
I looking at my first used gasser. I see one that's for sale that has an O.S. GT 55 gas in it. I'm not familiar with this and neither are friends at my club that fly gas. Through my searches I come up with some bad ignition modules, and that they don't make them anymore. That being said does anyone still use one? if so what's your opinion? I'm also curious when and why they stopped making them.
Any advice would be appreciated,
Thank you,
Pat

MTK

The OS GT55 was the first gassie OS introduced maybe 5 years ago. The ignition module required the engine to be smartly turned at start up because it has a low rpm (around 150 rpm) requirement before it kicks, It's a safety thing. Some people had some problems with engine starts. Some people did not. The engine required new handling techniques compared to other engines and so folks got tired of the difference and bad mouthing started.

The engine puts out a lot of power for the displacement. It was discontinued because OS decided to bring the OS GT60 out a couple years ago. It too is a very strong engine better than most. It still has the same CDI requirements at start up as do all of their gas engines.

If less experienced with any engines, you may want to stay clear. On the other hand, if the price is right and you have been around engines a while, you just might find a fine engine and learn its habits and field manners

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Hi Matt,
Thank you for taking the time for the detailed reply. I have no experience with gassers yet but do have some friends down the field who will help me out when needed. Right now I'm thinking about what you said call him and make an offer that I feel secure with, this way I'm thinking is that is the price is right I can justify it as a learning curve.
Thanks again,
Pat

scubaozy

I got a brand new os gt 55 in second hand market. Because of my cowl shape and installation, I will have to remove the velocity stack. Will this cause a lot of power loss?

kmeyers

No I don't think power loss if tuned right, but, it could have some (very little) fuel and oil escape mess.

scubaozy

Thanks for your help!