HerrSavage

Anybody running the OS 25? If so, how is it?

HerrSavage

http://www.youtube.com/watch?v=Cs2_6HCbk7A

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supertib

I tuned a OS 25 this last weekend..... originally it wasn't overly impressive, running a P3 plug and a OS2050.......after a little needling I went down to a P4 plug and installed a OFNA 086.......After a little more needling the engine was ballistic...it has killer low end and screams on top end...almost more impressive then I remember my stock OS28 being...... The owner of the machine was not able to really use this engines power, but regardless it is a killer engine if setup correctly, probably too much for most racers tho.....

secretsg

Great engine. More punch than any of the 21, and only loses the rev battle if you got a big straight. You will need a 2050/2060 or re10/11 with it for best mileage/performance.

The carb is more sensitive than other O.s engines, and will not be as forgiving to bad tuning settings.

supertib

The OFNA 086 so far is the best pipe we tried on the engine...runtimes went up, tuning got easier and the top end really woke up... The OS pipes are too restrictive for this engine , it really likes the more open 086...... If you think a 2050 is fast, wait till you try a 086...huge difference !

HerrSavage

I maybe need to try a Dynamite 086 then, cuz my Ofna 086 has made every engine I've tried it on impossible to tune..

I doubt I'll get one, but it would make a nice engine for my SC8... [>:]

secretsg

"
This would not be "golfman" 's 25xz would it?

supertib

Yes it would !!!!

his was wanting to "ping"with the 2050 and P3.... we could needle it out, but then the tune was too rich to be practical....a switch to a cooler plug and a better flowing exhaust cooled the combustion off a little and allowed us to get a sharper tune on the engine..after that the engine was ballistic, even set a tiny bit rich it hauled ass.....because of the cooler combustion we were able to get a leaner needle setting and the runtimes went up ....As well I noticed the tuning window broadened as the engine was less less prone to "pinging" .....I have seen in the past some of the big HP engines get bottled up by some of the more restrictive pipes, resulting in quirky tuning characteristics....many times a switch to a more open pipe can make a world of difference.....

with that being said, the engine felt quite aggressive on the 086, it tuned great and ran cool...but the feel was very abrupt and maybe not ideal for many racers...tho it was dam impressive, right from bottom to top...it would take one hell of a modded 21 to run with it on most tracks....I could only imagine what a modified version could be like...