savage 40

Anyone know the factory carb settings for the os 70fs surpass engine? thanks

Gray Beard

My Feedback: (-1)

Go on over to Giant Scale, then punch up the Gas Engines Forum, then Manufacture Support and OS.
Bill Baxter is there and is the OS rep, he can tell you anything you wanted to know about your engine.

saintcreed

My Feedback: (205)

Close the carb, check it visually...then and only then screw the low speed needle adjustment in 'til it stops...back out 1 1/2 turns to start...now if you open the carb barrel and look at it there should be a small space between the two small tubes that you see...they use to be called a spray bar, god only knows what they call them now..that space should be around 1/64 to 1/16 " ...to see what you're adjusting when turning the low speed adjustment...hold the carb barrel open and start turning the low speed adjustment screw in and you'll see that space that one should have disappear...Your high speed should be around 1 1/2 to 2 1/2 turns open from the closed position...now start the engine...set the high speed...then go too idle...let idle give or take 10 seconds...go to full throttle...if the engine dies...it's too lean on the low end...open 1/8 turn to start with and increase again if it dies at acceleration again...if it sputters and dies,or sputters and catches it's self...it's too rich...turn the low speed in 1/8 turn and try again..repeat as often as you have to to get it right....then set your high end 2-300 under max rpm's if you want to treat your engine with some consideration..if not max it out and pray it last more that a couple of gallons.....and again check the low end again...same procedure...let idle 10- 15 seconds or so, then advance..make any changes you have too....you should end up with a smooth quick rpm gain from idle to the top end..I'm sure if I've forgotten something here someone will be sure to let us both know real soon...but this is the way I set other club members that can not seem to set an engine up properly, and are constantly fumbling with their 4 strokes..By the time they ask me they have the carb adjustments all out of whack...screwed up..so from experience I just look at the carb with it open to check the gap and then I can go from there..hope this helps you out....the 70's are great running engines...and will last you for quite awhile if treated right..