hey guys.
i got an old homie XL-1 chainsaw that i started to strip down for a conversion.
it's gonna be run in a pusher config with the prop hub where the clutch usually goes so i can use puller props in pusher config. (some of you know that i run airboats)

but this thing has MONSTER compression and when i hold the decompressor valve in with my finger i can't pull it over (pull rope) at all due to the compression!!!
if i let the compression valve go it spits it out and will turn over with a little compression still there.
in the original setup there was a spring that held the compression valve closed but from what i can see, if it got say a hoge explosion or backfire it would blow out the valve and the spring would replace it.
understand?
it is also a reed valve engine

i need to get some pics for ya'.

but i want to know if this kind of compression is to much.
a review said that they like the high octane petrol mixed at 32:1.

shaun

today i bolted on a prehistoric tillison carb with around a 12-13mm venturi and mixed up some gas and normal 2-stroke oil.
i put this in a dubro tank with what ever little 5-18 fuel was left in there (around .5oz) and primed it up.
a cable tye around the decompressor to hold it in and i fired it up on gas/glow because the original ign had conked out for the moment.
let i idle for a while and tryed to run away from all of the smoke pouring out of the muffler LOL.
i killed it by puting on the choke.
all of that was achived withought glow power to the plug.

i liked the smooth idle so much that i will keep it on gas/glow with no nitro at all ($$$ and it has the high compression so it's ok)

so now i need to turn up a prop hub on the lathe and then get a large prop, i'm thinking a 20" APC?

but the bad news is that one of the 3 crank case bolts broke off[]
that did not affect the perfornamce yet. i'll have to drill it out and tap a new one.
here are soem pics after a test run...




shaun

Everything you have done seems okay so far.

For removing the screw. they make left handed drill bites.
Usually when you drill a broken screw or bolt with one of these they catch and back out the
piece all by them selves. With the head broken off they should be free and come right out.

Were did you get that glow plug adapter?

CAN YOU POST A PHOTO WITH THE RECOIL OFF? THANKS Capt,n

yeah sure captin

and ki8fer,
i made the adapter from some steel bar stock in the lathe, no taps at all!!!
shaun

must be nice to have have one lol

Hey Shaun!!! how do people take the Gas/Glow experience down under[sm=tongue_smile.gif] do they accept it well or they are not believers yet

as far as i know no one else has done it but mind you, i don't go to magor flying clubs either and i'm also in the little secluded island below australia....tasmania.
but going to a flying field is on my to-do list
i only got into rc 2 years ago and i'm 15 y.o (i leart to machine from my dad who taught me how to use our old myford lathe)

adn to anyone who does not have one, GET A LATHE!!! that is if you have the time and money.
even if you cant do the complicated stuff it is still handy to take of that few mm's or that outside diameter (O.D)

i will get the pics for you tomorrow captin, fogot the camera today.[]
shaun

Shaun: Sounds great....a photo is wort a thousand words!!!!!!!! Capt,n

Shaun, this engine looks identical to the one I just converted to Gas\glow. Mine came from
a Super EZ saw. It measures 41.? CC and has a 4 reed intake. I broke a ring when I took
it down so I put in Bowman rings. Seems to have very good seal. Need some good weather
to run it. I tried to upload a picture, but it doesnt seem to accept it.

from what i have heard,
the super eZ and the XL-1 have the same engine
i'm going to get thoes pics now.
shaun

Hi, Aero Nut

YES, I am a believer
I have had a 52cc chainsaw (Mg alloy crank case) converted running gas-glow for almost a year in Melbourne. It has enough thrust to pull a H9 CAP232G vertically unlimited (Bolly wood 20x10 at 6800rpm or 22x8 at 6500 rpm, idling at 1700~1900 rpm). The mixture I use consists of 3% oil (Cool Power syn), 3% Nitro Methane, 20% methanol and 74% Unleaded Petrol.

I'd like to thank all of you for this great conversion method !

Cheers, Aero122

does anyone know what prop i shouls start with on this 41cc engine?
i would like to use APC props
shaun

18x8 to start with. Then see what it will do with a 18x10 if the # are to hi with that 900+ then go with a 20x8 to 20x10 but I bet you will get the best out of that engine with a18x10

Paul

do you think i could use a 20x6?
to lower the pitch a little adn get more low end thrust?
shaun

yes you can but the bad thing about going that big is with 40 to 45 engines that I have had running 20 props is. The rpms do not come up as fast. I would have midrang problems. It is good to start out with a 18 and just play. If it runs good with a 18 and you go to a 20 and start to have midrang throtal up problems you know it is the prop.

Sorry for the spelling I do not have time to use the checker.

Paul

i'm after the maximum amount of thrust possible, not speed.
so if i could find a 20x2 i would go for it but i'm simply not going to find it lol
ok then maby i'll go with the 18 incher but i might have to experiment.
shaun

I think with that engine a 18x8 will do what you ask it too. On most of my 40 to 45 engines I will run a 18x8 to get that pull. I ran a 20x8 one time. (prop Not ezy to find) and it did ok but it was just to much swing. but it did work.. I know to be able to test good you need 4 to 5 props and they are about 15 to 20 bucks. Not cheep just to see what prop is best for what you want.

Paul

i got an idea!
after talking to another guy who has a homie 240 39cc spinning a 18x10 at nice R's i thought,
what about APC's 19x8 wide blade prop?
it is the cross between the 20x8 and the 18x8 so maby it might be worth a try.
a wide blade prop "grips" the air better correct? therefore giving more traction for a more efficient prop at lower rpm's.

shaun

I use an APC 18X6W on my 31CC Ryobi and it swings it at 8100 RPM, that's the best prop I found so far, so I would go and try the 19X8W and see how it works.

Also a heat gun on an APC prop and you can change the pitch.

It is done often.

Ralph

oooOOOOOOooooo that sounds cool
can you elaborate on that a little?
shaun

today i got some time to get a bit of work done to the engine.
but the question is...is it worth converting?
the reasons,
got the jug of today and the engine has been previously siezed, scoring filled with carbon on exhaust side of piston.
there is a fair bit of big end slop which is likely to get worse.

but on a good note, it has high compression, a good seal and an "L" ring (pretty rare now days, just a 1/4" thick single ring)

due to these problems is it worth doing the conversion, i was planning on getting a CH ignition module cause it has ol' points ign[&:]
what do i do? try and find a better quallity engine or use this old clunker?
shaun

If the scoring is above the ports it's junk, below the exhaust port there's hope.

You can change the pitch of a APC prop with a heat gun.