LANNYBOB

my new o.s. 91 fx 2 stroke has been running good but lately the son of a beach dies when throttling back to idle. any ideas why

proptop

My Feedback: (8)

Maybe it's mad at you.... you calling it names and all...
Could be dirt in the carb idle passage?
Could be the plug is getting old?
Could be a combination of several things...
How's the compression?

LANNYBOB

compression is good its brand new it ran fine last weekend. i changed all the lines from the tank after noticing a pin hole in the muffler line. maybe thats what did it but i doubt it.

proptop

My Feedback: (8)

Sounds like either a lack of fuel, or it's loading up, or the plug is junk...
Try putting a new plug in it and see what happens.

DiscoWings

My Feedback: (76)

since when can a beach have a son???[:-][X(]

Scar

My Feedback: (3)

The only time my .91 FX ever failed to perform perfectly was when I opened a new jug of fuel which happened to be bad. My .40 FS-R just ran crappy, like it had a bad glow plug, and died in the air sometimes. The .91 FX didn't run crappy, but it died when I idled down, then tried to throttle up.

You might try a different jug of fuel. Good luck,
Dave Olson

alan0899

G'day Mate, If it's new have you checked the idle mixture with a pinch test, as the motor runs in the fuel suction to the carby increases & you may find you can lean your idle mixture out slightly. Also the plug won't last forever, if the motor slows down a fair bit when you remove the glow driver, suspect your plug especially if it was running fine before.
Good Flyin Mate.
Allan.

sigrun

Is idle RPM lower than it was and is it high enough? You might just have the idle set too low if it has altered with use. ie: Throttle linkages can alter the barrel position (opening) with wear - and weather depending on the extremes of temp and material used. if so, re-adjust the barrel idle postition with sub-trim to ensure the idle RPM is appropriate.

Problem solved? No?

Changed fuel brand/ mix? -> Adjust the idle mixture.

No, or it makes no difference? -> Replace the plug (with a new one). Deteriorated (worn or damaged) plug is a common cause.

It makes no difference? -> Adjust the idle mixture. When the seasons change, so does the mixture.

No joy, report back.

Sport_Pilot

Brand new engines have a habit of requireing additional tuning as the rings break in. As it breaks in suction improves, especially at idle and thus your idle setting becomes too rich and requires leaning out.

rctrax

It's a two stroke

Sport_Pilot

So? Your point?

Semi Retired Aviator

I think rctrax likes 4 strokers.

speedster 1919

My Feedback: (3)

Your engine was probably tuned with pinhole fuel line and now that you replaced it you have to retune low and high speed needle. Your now getting more fuel pressure.

Imac Kiwi

In my experience with the OS 91fx, the idle mixture setting is too rich from the factory.

JettPilot

My Feedback: (6)

Get a 4 stroke, they idle better

Sport_Pilot

?? They don't idle any better. Perhaps you never had a good two stoke?

LANNYBOB

you guys are right. love you

LANNYBOB

you guys are right. love you