2 Stroke Tickover Speed?

[Manish Chandrayan]

Each engine and the model the engine has been fitted to will dictate the idle rpms. For the low end I do not tach the numbers (other than just out of curiosity).

My method is to set the low end so that I get lowest possible idle on the engine and clean transition after a slow count of 15/20.

Thereafter the trims are set with stick at the lowest position. I aim for a trim setting where the button/cursor is somewhere in the middle and with the throttle stick down and engine idling the model should not roll on ground. Additionally the throttle cut switch should cut the engine by closing the barrel/butterfly completely.

 

 

[Roger Dyke]

Thanks Manish. Taken on board and noted.

[Simon Lumsdon 1]

+1 on comment RE OS FP 40, very docile engine, reasonably powerful, easy starter and no bearings to worry about either 🙂

[Cuban8]

5 minutes ago, Simon Lumsdon 1 said:

+1 on comment RE OS FP 40, very docile engine, reasonably powerful, easy starter and no bearings to worry about either 🙂

Almost a classic now .......had one back when they first came out in the 80s/early 90s IIRC.  Always came with a simple  airbleed slow running adjustment that worked very well.

I think the snag with a lot of the Chinese clones is that they did sometimes let themselves down on the carbs. Maybe the manufacturing accuracy just wasn't there or varied from OK to a bit rough depending if you were lucky or not.

I've had a lot of ASP and SC motors, both 2S and 4S and some could  be ultra sensitive on the carb setting, in particular the idle needle. You generally could get them right but it would  only be after the motor was very well run in and then a very light hand was needed to get the tick over correct. Even less than 1/16 of a turn on the slow running jet would make a big difference so half of that movement again i.e next to nothing would be needed to get things right or as close as possible.

A lot of patience would be needed - something that many flyers aren't blessed with.

[Roger Dyke]

I have just removed an OS 40FP from a model (unscheduled arrival.....). I remember purchasing it new back in the 90's. 

100% reliable engine. Best engine ever.

[Engine Doctor]

For the "Oily hand society" The FP engines and their clone the Magnum 40 GP wich is equally as good , convert very well to diesel and can swing much bigger props. The small diameter carb give good fuel suction and throttles well as a diesel.

Edited September 13 by Engine Doctor

[jeff2wings]

Can confirm that they convert to diesel well ,the FP's are a a better engine than the LA series 

 

as far as idle speed I aim for 2,500 -2,800 on the ground and use thr idle down function on landing approach 

[Nigel R]

3 hours ago, Engine Doctor said:

For the "Oily hand society" The FP engines and their clone the Magnum 40 GP wich is equally as good , convert very well to diesel and can swing much bigger props. The small diameter carb give good fuel suction and throttles well as a diesel.

 

Ah yes - Magnum GP40 - part for part compatible... I have two FP 40s, both with Magnum GP piston, liner and rod, which run just as well as they ever did with all OS parts 🙂

 

 

[Engine Doctor]

3 hours ago, Nigel R said:

 

Ah yes - Magnum GP40 - part for part compatible... I have two FP 40s, both with Magnum GP piston, liner and rod, which run just as well as they ever did with all OS parts 🙂

 

 

Story going around at the time was that the designer of the FP 40 left OS and went to Magnum hence the clone ? who knows but it sounded good at the time .

I found the Magnum parts were half the price and of better quality than the OS and as you say 100% interchangeable . 

As Jeff says the FP were beter quality than the LA,

Edited September 13 by Engine Doctor