Antique

My Feedback: (4)

OK, here's the Troy Bilt 25cc..
2 lbs 6 oz as shown, including ignition, no muffler..

arobatx

performance specs yet?

Antique

My Feedback: (4)

Broke my tach, ran it with a Mejzlik 18-6 and an old 18-8 wood prop, looks promising...
Great case for mounting, needs no standoffs...They come as short blocks with no carbs..That one has an old Tillotson from a Q35..Mine will come with Walbro WT624s, 11.1mm, 2 needles and a choke...Carb is on a G10 rotator block, Ignition will be Chinese, spark plug can be an CM6 or NGK BPMR6F...5/16 grade 8 prop bolt, 2024 aluminum hub, 28 BTDC timing...
Looks like a competition, China VS Taiwan, me against the world , at least until the supply of TroyBilts runs out ....

av8tor1977

My Feedback: (6)

Looks good. It actually looks a little like an Echo/Kioritz...

Good luck Ralph; give 'em hell.

AV8TOR

triangle

My Feedback: (3)

can you let us know how it compares to a g26 so far???

GoeKeli

My Feedback: (18)

Ralphy,
this might be a good airframe for your new engine.
http://www.hangar-9.com/Products/Def...ProdID=HAN4500
A light pipe somehow incorperated and small high pitch prop.
When will you get RPMS and thrust ratings? Can you give some dimentions?
Would this type of engine benefit from a pipe?

joe

captinjohn

Here is the RCIGN1 25cc engine and the 80 inch race plane by Hanger 9. Capt,n

Antique

My Feedback: (4)

It's about the same weight, but the transfers and port sizes are smaller...It compares favorably to a G23..There is lots of room for improvement...Haven't had time to do much except converting...
There is some wishful thinking in the advertising for the Sundowner ARF, 120 mph is not possible with any of the gassers that would fit in it....About 100%
Even if a 26 could turn an 8 pitch prop at 8000 rpm, the speed would be closer to 60 than 120.Takes a 16 pitch turning closer to 9000 to go 140....
No 26cc gasser ever made will do that.....

rangerfredbob

My Feedback: (13)

is there a reason you went with a agrade 8 prop bolt threading into 2024 aluminum? those are opposite sides of the spectrum...

Antique

My Feedback: (4)

Exactly....The grade 8 bolt can be tapped with a 10-32 for a spinner, the 2024 is almost impossible to strip by tightening it with a prop on it...Tried it using a 10 inch wrench...I could strip a 6061 hub, couldn't strip the 2024 without a longer bar on the wrench...CYA in action

foamcut

My Feedback: (40)

Ralph,

Have you tried a WT324 carb? I've found a source for cheap WT324's but not the WT624's.
I looked at the specs between the WT324 and WT624. The primary difference appears to be the needle assemblies used.

Thanks

Antique

My Feedback: (4)

The needles on the 624s don't have a slot, maybe the others do...The 624s are made for a remote primer bulb, it needs to be plugged......A 2-56 tap works to thread the tube, then a short screw....the 624s are not too bad when you can get them wholesale

ROOSTERLEW

Care to share this source.....?

foamcut

My Feedback: (40)

Try "theplacenashevill" or "swanprop" or "small-engine-deals" as a seller on eray. All three have been great sources for carbs.

captinjohn

Foamcut: Thanks for the tip on where to find carbs. Best Regards Capt,n

rcflyerds

So I picked up four of these engines because they sounded like fun to play around with and at the right price. Got everything that's not a model airplane engine stripped off (staying with a mag ignition for now to see how it runs) but I'm a bit puzzled about carburetion. The stock carb is a Walbro WT 675, single needle. When I took the carb and spacer block off I was surprised to see that there is no pressure pulse hole in the head. The carb and spacer block both have such a port as do the gaskets, but there is no matching hole in the side of the head to feed pulses to the carb. The carb itself has no pressure line, so I'm wondering how it functioned, but more to the point, when I replace it with a two-needle carb, how will the new carb get the pressure pulses it will need to work? If I need to tap the case for a pressure line, whereabouts would be the best place?

And speaking of carbs, based on what I've been reading on RCU I'm looking at a WA 167 or WT 624 as possibilities. Anyone in the know care to advise me as to the "appropriateness" of either/both of these? At some point soon I will also have to pester someone for a muffler for this guy, so pointers in that direction would also be much appreciated. Thanks guys.

PS: RCIGN1 - any more news on the one you converted to ignition?

captinjohn

rcflyerds: Welcome to the krazy world of collecting engines that need to be converted for use on RC airplanes! If your like the rest of us...you will find more before you finnish all the ones you just got. Best regards Capt,n

rcflyerds

Capt'n - Thanks for the welcome. I'm afraid I'm already neck deep into the conversion world-so far I've done two Ryobi 31's, a Mac 28 and a Ryobi 4 stroke. Now I have these 25cc guys burning a hole in the workbench... and would you believe none of them have been in the air yet! I keep playing in the shop with motors and don't seem to make the airplane connection. I'm inside a block from a nice city park so every now and then I run over there with one of my electrics and throw it in the air. I do have a Stinger 120 that I've built light that's got one of the Ryobi's mounted on it-well, dismounted again until the covering is done. My basement is full of glow planes, smallest being an Ace 4-20 with a 30 4-stroke, to the largest (and yet in the bones) which is a third scale Sopwith Pup that has a G62 waiting (and I'm not even going to tell you about the 12 other planes that are between those two..). I really need to get out this year and "thin the herd" a little.

So any advice on the absence of a pulse pressure hole on my 25? I think I need to pull the carb off another one and see if it's the same or if I just got one odd one.

Dennis

captinjohn

rcflyerds: I have a engine just about like yours. It has a pulse hole about 1/4 inch down from edge of intake port. And in line with center of port. It is a strait into crankcase and 1/8 dia. I can take a photo tomorrow. Is that where youe hole is in the gasket? OH, the port is fully open when piston is a top. Regards Capt,n

foamcut

My Feedback: (40)

RC,

Your post made me go back and check mine all of which have the pulse hole.

Frank Bowmen now makes rings to fit this engine.
Ken Lambert makes a muffler for this application.

I would like to know more about your Ryobi 4 stroke conversions when you have time.

Thanks

rcflyerds

Capt'n & Foamcut:

After reading your replies curiosity got the best of me and I popped the carb off one of my other engines and it DOES have the pulse hole just like your picture foamcut. All of my carb gaskets from both engines have the pulse hole just where they should. My only anomaly is that the pulse hole is missing on my first engine. I think what I'll do is tear down #2, see what the pulse hole does on that one and then duplicate it on my #1 engine-I suspect it goes straight in as you said yours does Capt'n. Sounds like quality control in Taiwan sometimes parallels that of some of the mainland China engines now and then.

Foamcut - thanks for the tip on the Bowman rings. I did get a pair from him for one of my Ryobi 31 cc conversions and now that I know he has them for these I'll probably be scratching at his door again. I'll try and take some pictures tomorrow of the 4-stroke Ryobi conversion and post them for you. I haven't run it yet as I'm not happy with the mount that I fabbed up for it. One of these days I'll get back to it and toughen the mount up to where I trust running it.

Anyone have a comment on my question about which carb I should use on these 25cc guys? WT 624? WA 167? Other?

buck1856

My Feedback: (49)

I checked mine and the pulse hole is dead center of port,1/4 inch below and on left side of lower intake bolt hole.yours must have been missed.maybe this is why they canned some. .if you also look at the front flywheel nut youll see the two holes for the starting pawls are off set,at least on mine but when i put a prop hub on mine it doesnt matter because the flywheel and hub are true,only the pawl holes are off.Mine weighs 3.5 lbs as shown in the pic,stock carb.I cut off the flange around the set screw on carb to adjust the needle then i used a hacksaw to put in the slot for a screwdriver.I have an echo 24cc and ill put this engine against it any day.Prop in pic is a 16x8 dynathrust,tach broke but this engine is screaming.

rcflyerds

buck 1856:

Thanks for checking your engine, and for the info about the starting pawls. Your comparison of this engine to your echo 24cc really sounds encouraging. In one of the attached pictures you can clearly see the lack of a pulse port on my original engine. At least one of the other three I have DOES have the port, haven't checked the other two yet. Now that you've so favorably compared this guy to your echo I'm even more excited to see what mine will do (if the summer honey-do projects that are showing up don't slow me down too much!).

foamcut:

I've attached a couple of pictures comparing my 25cc troybuilt to my 26cc Ryobi 4 stroke, and the size difference is remarkable. There is just a tad bit of difference in the weight as well-the troybuilt as you see it without carb and muffler weighs 2 lbs 9.4 ounces, while the 26cc 4 stroke weighs a whopping 5 lbs 6.2 ounces WITH muffler, carb and mount-just short of a 3 pound difference as you see them in the pictures. I don't want to hijack this thread so I'll pm you some other links about the 26cc.

Now to all - no one has as yet responded to my question "what carb should I put on this troybuilt?" Anyone??

Dennis

captinjohn

For that Troy bilt 25cc....try a 11 mm Walbro with 2 needles. One is for Hi speed mixture and other needle is for low speed mixture. Good Luck Capt,n

buck1856

My Feedback: (49)

I have a WT499 wich is the one for a G-23.it has the number 27 in the intake stamped.this flows a lot of fuel.picked mine up on here or an auction for 25.00 brand new.i also have a wa157 wich has a 24s in the intake,this is a 10mm carb or close.check out walbros website or do a search here on rcu for walbro carb or 10mm carb and i think theres a listing of the 10mm carbs,ill go look or check the walbro website.All i know for sure is to look or ask what the number is in the intake,thats what i do.anywhere from a 24-28 will work fine.it is in 64ths,the number.the carb on my 24cc is stock,not a 10mm by the way.you can use the numbers posted earlier in this thread,especially anything posted by RCIGN.