G-51 !
Seems that ALL the Chinese made / assembled Versions have a 4 didgit number stamped on the EXHAUST SIDE Lug .& like ' CHINA ' in the backplate cavity .
Theres That , no ' made in Italy ' under there version . And the one still , before they changed the die . ?
Some of the China ones , theyve deleted the protrusion on the bypass side that gets in way of the screwdriver / bolts , there .
So this here below is the LATER ( Last ? ) Chinese version .
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Brian Wynch said to me , personally , first person etc etc . Wether it was correct of course , I couldnt say ,
That the Chinese had asked him if there were any ' improvements ' that they should make to the engines .
He said He'd said ! , the Carb needed some modification to the track , or somesuch like .
AND " The Ring was to hard " , " and so theyve put a softer one in it , so it needs less bbreak in "
Wether this is a load of cobblers ive no idea. Brian Winch is the ' Airborne Enigineer ' and does a engine column in the englih Aeromodelor mag .
Mostly a rant & He was a cop ,
so bu##er me , likely .
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As For BREAK IN , on the RINGED Version . Ive four , three italian . after twenty years the bearings got past it on one , from nitro NOT wear .
Ones a first China , " made in Italy on the casae , as per Italian case . Number on left lug. " CHINA " in Backplate .
So first place to LOOK is up the backplate .
Anyway , where were we ,
Pre Lube ! should at least throw some fuel in it , or ATF , or maybe Syn. Flip it through thoroughly to distribute .
Mount up Etc the throw a good dose of fuel in , remove glow plug & flip ovr untill cleared, or the plug will oil .
Give a prime ( no fuel line connected ) and get a ' burst ' on a prime or three . WINTER and a bit of nitro in the prime is likely necesary .
Tho they run real good on no nitro & I doubt if theres a output differance , and the needles reasonable .
Then I give em a few two - five second bursts .
Theorey was any hig spots dont heat & break through the oil film . But modern machineing , high spots are improbable .
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A few 10 to 15 second bursts . By now youll likely have caught the needle correct , at ' the break or out down in the fourstroke . Maybe 3 turns thereabouts.
If your a hill billy and driven all the neighbours out , No Muffler itll run cooler for break in .
The silent mufflers real good , and no power loss , theres a big flash ' Q 500 ' ST 40 Q500 muffler too , that breaths easy .
Being fussy you then give it a few one minute runs . Idea being to get it still so you can about keep your hand on it . The FINS not the muffler !
Thats 90 degrees out there , if you dont Grip It & get burnt .
Let it cool as necesary between runs . A minute or two in winter , maybe 10 or even more in summer ! so we prefer winter for break in .
Now everyones happy and you put the rest of 2 litres / 2 quarts of juice through it , on the bench . and have it pretty much in a solid four
for the first flights , and try not to have it lean off during the first gallon .
One of my two original , of three & the China job , measured last week , still had 5 1/2 Thou. measured ring gap .
Delacquerd it & replaced the bearings , on Mark Battys advice , as it'd started to stop early ,
as explained " the Nitro gets the bearings and you get bits of metal in the plug , shorting it out "
Which having replaced the bearings with used Jap / taiwanese Manum ones ( I know , skinflint ) it has recovered from .
So the two ive used most have both survived well . Usually use afterun oil or CRC at least . Likely now I will flush them , occasionally at least , beforehand .
Havnt run intake filters , most of the use was in NZ , a lot of fine dust here in Aus. Youd need to compare hardness ( a Brinall test ? ) to see if true on the ring. )
Topic: ST.51 Gardner P&L set Break In (Read 1257 times)
