Andy McC

I have a Mag 52FS that was having trouble maintaining a low idle. Using the pinch test as above is how to set the low end, however I still couldnt get it to idle reliably. Finally discovered a pin hole leak in the tank under pressure (this was a new tank) by immersing it in a bucket of water etc. I wish I had checked it first would have saved me a lot of trouble. Anyway after replacing the tank and setting the valve clearance ( they needed it) and checking the timing (to make sure) the motor now has a low steady idle and instant response. So check the valves, timing and tank if adjusting the low end needle does not fix your problem.

LDM

My Feedback: (15)

I was working on a few engines this weekend funny you menthioned the magnum 52 , its the only engine I worked on that did not work with the prescribed method . My Os and Saitos set fine , very happy with the results .Thanks to all
The magnum wont respond much at all to the surgical turns of the set screw , it was the only one . I went thru a list of checks , no apparent leaks in tank visable to the eye , changed os plug glow plug for new OS plug , ect ect .
My concern with this perticular engine was that when it was new I had to send it back ,(it would not start at all ) Hobby People said the carb was bad and they replaced the carb .
WHats strange is that the engine does not respond (or very very very little responce to tiny turns of the set screw or bigger turns or the high speed needle valve , it seems happy to run at high mid range . I am wondering if the carb is bad . I will say that the high speed neddle valve seems to have an abundant amount of fule on it , almost droplets when the engine is at high speed , I am wondering if there is a pinhole leak in the fule line
near the engine attachmnet point

Flyboy Dave

My Feedback: (21)

Just checking....you say:
....and:
What "set screw" are you refering to ?

FBD.

LDM

My Feedback: (15)

I am just referring to the low speed needdle valve , sorry for the confusion

Kmot

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Cyberwolf

My Feedback: (4)

Hi dave I have to agree with you here ,I like you learned the process by myself many years ago. But not everyone can do it.
We have a guy at our field that knows nothing about how to tune his engines on the bottom end, even though he has been walked thru it many times .He is a very nice fellow but just can't seem to get it right in his mind on what to do . So rather than watch him lose a plane, either myself or someone else will get him going.The guys not stupid just not mechanically inclined at all.
Theres is one good thing about him though ,after you get it adjusted he leaves it alone for the most part .

Sport_Pilot

I recall that one of the old time pattern pilots would help Don Lowe tune his engine, apparently Mr. Lowe though a very good pilot was not very adapt at tuning the engine. Back then they were using ST Blue Heads with the bent main needle and collet. Apparently another pilot on the USA team helped him tune the engine, then Don later readusted it and has a bad run because of it. So one of his team members readadjusted it and broke off the needle flush with the collet so he couldn't adjust it again!

LeeHop

Flyboy Dave wrote:
...Leave the glow starter on the engine...

With respect I would like to ask - why? My first impression would be to duplicate actual conditions and leave it off [>:]

Tnx - LeeHop

Flyboy Dave

My Feedback: (21)

Simple....you cannot adjust the engine if the fire keeps going out. You must
keep it running to adjust it. Once you get the adjustment close, it will continue
to run when you remove the glow....then you can make finer adjustments.

One thing to keep in mind, the glow plug burns brighter (hotter) when the
battery is connected. It acts like a "hotter" plug than it actually is. In this
case, an engine set a bit too rich will run Ok when then glow is still connected.
When you remove the glow starter, and the engines slows down a bit, that is
an indicator that the engine is still too rich.

FBD.

skiman762

I dare say Dave is right about leaving the glow starter on
if it runs good with it on it will run good with it off
why mess with restarting constantly to achieve the same results IMO

LDM

My Feedback: (15)

well all the advice paid off , even got the old stuborn magnum 52 to work perfactly , may it was me that was old and sturborn for not asking for help sooner .
Thanks guys , the tips worked great , printed them for a file on tuneing engines .

Flyboy Dave

My Feedback: (21)

Way to go, LDM....well done. [sm=thumbup.gif]

In the Air Force they have a class for NCO's called "Train to Train". In there they
say that the easiest person to train is the one who is asking querstions and wants
to learn. That person is also hanging around after class listening to the instructor
chit chat and answering questions. That person is absorbing every piece and scrap
of information the he/she can.

That person will be sucessful.

To the naysayers...........

LDM

My Feedback: (15)

Thanks Dave , I have to tell you , its changed my entire ability to land gracefully . I always laneded my warbirds fast and know it comes with the territory but I was forced to land faster then nesssasary due to throttle issues . It did make a better pilot lol , but I did not need a heart attack on approach every time !!!
Thanks agian

Texan2

My Feedback: (4)

I have a brand new ys110 in my ge p-40. Should i follow the manufacturer's instructions on initial needle valve setting (1 1/2 turns out)? I noticed it would quit at half throttle with the glow battery off. I did discover a loose fire wall and I am currently correcting that problem. before I get back at it. Any tips?

Flyboy Dave

My Feedback: (21)

It should run fine at the factory recommended settings, if the fuel system
and the fuel is proper. Use 20/20 PowerMaster YS/Saito fuel if you can
get it, and an OS "F" type plug.

FBD.

LDM

My Feedback: (15)

carl as i learned the from FB Dave and the others if that does not work do not be afraid to adjust the slow needel valve . I have stayed away from that part of the engine because of the urban lengend stories I was told long ago . I am now convinced that it may be a very intrical part of fine engine tuneing