Ryobi on Fourstar 120
#1
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From: Jenera,
OH
Hello,
Just thought i`d give brief rundown on my 120 Fourstar with the 31cc Ryobi. Great combo in my opinion! for anyone looking for a plane to put the Ryobi in. The plane came out just a tad over 13lbs. Moved the firewall back about 1.5", put servos in tail, still had to add little tail weight. Its a 31cc 2ring engine, so far been getting around 7,800 rpm with an APC 18x6W. Excellent verticall perfomance, was pleasntly suprised. I used the Paragon conversion kit, except for the muffler which is from Bennet. I used the primer bulb and choke, but dont think the primer is necassary. It does need to be spun over fast to start though. With a fast spinning starter it starts imediately. Has been super reliable so far, and excellent idle. I only put a 14oz. tank in it, but will run forever. I think glow powered planes are becomming a thing of the past for me
Love the cheap reliable gasoline powerd engines.
Gregg
Just thought i`d give brief rundown on my 120 Fourstar with the 31cc Ryobi. Great combo in my opinion! for anyone looking for a plane to put the Ryobi in. The plane came out just a tad over 13lbs. Moved the firewall back about 1.5", put servos in tail, still had to add little tail weight. Its a 31cc 2ring engine, so far been getting around 7,800 rpm with an APC 18x6W. Excellent verticall perfomance, was pleasntly suprised. I used the Paragon conversion kit, except for the muffler which is from Bennet. I used the primer bulb and choke, but dont think the primer is necassary. It does need to be spun over fast to start though. With a fast spinning starter it starts imediately. Has been super reliable so far, and excellent idle. I only put a 14oz. tank in it, but will run forever. I think glow powered planes are becomming a thing of the past for me
Love the cheap reliable gasoline powerd engines.Gregg
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From: Jenera,
OH
The sticker on the weed eater says Ryobi 705R. I bought it last fall, from the Lawnstation on E-bay. As I recall it was listed as "Non-California Compliant". im assuming it does not meet there polution requirements. It has the long shaft also, which i like better compared to an older model 700r that i had with short shaft.
Gregg,
Gregg,
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From: Jenera,
OH
Ramduster,
I`m just using Hobbico CS64`s High Torq BB servos all around. Seem to be plenty for this plane. Its not a fast plane, but excells at slow flight. I might be wrong, but I think there made by Hitec. About $28.00 a piece from Tower. Its not a 3D plane by anymeans, but a great flier. I need to tweak the idle speed a little on the Ryobi, try to get it to slow down little more. The plane is quite the floater on landings. Also thinking of getting the heavier landing gear from TNT, the stock ones are real light and springy.
Gregg,
I`m just using Hobbico CS64`s High Torq BB servos all around. Seem to be plenty for this plane. Its not a fast plane, but excells at slow flight. I might be wrong, but I think there made by Hitec. About $28.00 a piece from Tower. Its not a 3D plane by anymeans, but a great flier. I need to tweak the idle speed a little on the Ryobi, try to get it to slow down little more. The plane is quite the floater on landings. Also thinking of getting the heavier landing gear from TNT, the stock ones are real light and springy.
Gregg,
#8
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Moved the firewall back about 1.5", put servos in tail, still had to add little tail weight.
Bill
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From: Jenera,
OH
Bill,
This is gonna sound rather odd, but I just drilled a 1/2" hole through the Fuse right above the tail wheel and put a 1" or 1 1/2" long half inch bolt, washer and nut on it. seemed to be just right.
might look a little odd, but can't really see it anyway.
It serves the purpose, cant be more than couple ounces.
Gregg
This is gonna sound rather odd, but I just drilled a 1/2" hole through the Fuse right above the tail wheel and put a 1" or 1 1/2" long half inch bolt, washer and nut on it. seemed to be just right.
might look a little odd, but can't really see it anyway.It serves the purpose, cant be more than couple ounces.
Gregg
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From: Logan,
UT
hey nice fourstar,
i'm thinking of building one with a toro 25? thoughts? I don't really want to do many mods, so will this be ok?
Erik
also i would love to see someone with that fiberglass cowl on one... still can't track down the pics...
i'm thinking of building one with a toro 25? thoughts? I don't really want to do many mods, so will this be ok?
Erik
also i would love to see someone with that fiberglass cowl on one... still can't track down the pics...
#13

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From: Riverton,
WY
Fly it for a while and enjoy it. Then think about a lighter engine. A CH ignition would save you about 3-4 oz in the nose and reduce the tail weight 1oz or so. Some would say thats an expenseve 5 oz but every bit helps
#14
I've got a 4*120 kit coming in the mail right now.
Engine is going to be a Ryobi 31cc.
I have searched and done a lot of reading on this conversion. I just can't seem to find any really specific numbers.
One guy says he cut the firewall back and had to add lead to the tail---but he doesn't state if he used servos in the tail or not. Kinda useless to know how much he cut the firewall back when he doesn't indicate if he used servos in the tail or not.
Another guy will tell ya he used 2 hi-torque servos in the tail and had to add lead in the tail to balance. But he doesn't indicate if he cut the firewall back or not.
I need specifics guys. PLEASE
How much did you move the firewall?
Did you put servos in the tail or not?
How many servos in the tail?
2 elevator servos? 1 rudder servo? 1 elevator servo? 1 rudder servo? Rudder is pull-pull on the CG? What? What did you do?
Did you use a mount from wacker engines? 2" or 3" mount?
PLEEEEEASE post specifics on this mod with the Ryobi 31cc engine. PLEEEEASE.
Thanks very much.
Engine is going to be a Ryobi 31cc.
I have searched and done a lot of reading on this conversion. I just can't seem to find any really specific numbers.
One guy says he cut the firewall back and had to add lead to the tail---but he doesn't state if he used servos in the tail or not. Kinda useless to know how much he cut the firewall back when he doesn't indicate if he used servos in the tail or not.
Another guy will tell ya he used 2 hi-torque servos in the tail and had to add lead in the tail to balance. But he doesn't indicate if he cut the firewall back or not.
I need specifics guys. PLEASE

How much did you move the firewall?
Did you put servos in the tail or not?
How many servos in the tail?
2 elevator servos? 1 rudder servo? 1 elevator servo? 1 rudder servo? Rudder is pull-pull on the CG? What? What did you do?
Did you use a mount from wacker engines? 2" or 3" mount?
PLEEEEEASE post specifics on this mod with the Ryobi 31cc engine. PLEEEEASE.
Thanks very much.
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From: mitchell,
SD
Hello,I built a Four Star 120 with a Homelite 25cc weedwacker engine a few months ago....it took about 2 months from start to finish working on and off...The kit went together super smooth and my homelite pulls it around very nicely,the weight is around 14 lbs I belive. I also put the servos in the tail but left the firewall where it was and cut the cheeks off.Flys great...Enjoy,Dustin
#17
ORIGINAL: hockeydust18
Hello,I built a Four Star 120 with a Homelite 25cc weedwacker engine a few months ago....it took about 2 months from start to finish working on and off...The kit went together super smooth and my homelite pulls it around very nicely,the weight is around 14 lbs I belive. I also put the servos in the tail but left the firewall where it was and cut the cheeks off.Flys great...Enjoy,Dustin
Hello,I built a Four Star 120 with a Homelite 25cc weedwacker engine a few months ago....it took about 2 months from start to finish working on and off...The kit went together super smooth and my homelite pulls it around very nicely,the weight is around 14 lbs I belive. I also put the servos in the tail but left the firewall where it was and cut the cheeks off.Flys great...Enjoy,Dustin
How far back in the tail are the servos? Are they under the horizontal stab? How far forward from the rudder hingeline?
PLEASE BE MORE SPECIFC
Thanks
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From: mitchell,
SD
Hey Rcpilet,I just took some more pics, Both servos are in the tail ,they are big hitecs,i forget the number, they are staggared to each other so they dont rub behind and they are both parallel to the horizontal stab,you can see in the pics the furthest foreward servo is in line with the leading edge of the horiz. stab,hope this helps...Dustin
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From: San Antonio,
TX
Hi,
Nice job. Since you didn't have a carb sticking out of the back of your motor, leaving the nfirewall stock is ok. You have to move the firewall back with the Ryobi to keep the cylinder where yours is on a stock setup. I guess it works out the same.
Dave
Nice job. Since you didn't have a carb sticking out of the back of your motor, leaving the nfirewall stock is ok. You have to move the firewall back with the Ryobi to keep the cylinder where yours is on a stock setup. I guess it works out the same.
Dave
#20
I got my 4*120 kit in the mail today.[8D]
I got the parts for my Ryobi from wackerengines a couple days ago.
I'm going to start framing the wings and tail surfaces. Just waiting on my new Ryobi from harbor freight. I'm hoping to get the engine before the end of the week. I wanted to get the engine and check out the mount setup before I started framing the fuselage.
Can't wait to get this plane finished and start flying it.
I got the parts for my Ryobi from wackerengines a couple days ago.
I'm going to start framing the wings and tail surfaces. Just waiting on my new Ryobi from harbor freight. I'm hoping to get the engine before the end of the week. I wanted to get the engine and check out the mount setup before I started framing the fuselage.
Can't wait to get this plane finished and start flying it.
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From: dobson,
NC
ORIGINAL: Rcpilet
I've got a 4*120 kit coming in the mail right now.
Engine is going to be a Ryobi 31cc.
I have searched and done a lot of reading on this conversion. I just can't seem to find any really specific numbers.
One guy says he cut the firewall back and had to add lead to the tail---but he doesn't state if he used servos in the tail or not. Kinda useless to know how much he cut the firewall back when he doesn't indicate if he used servos in the tail or not.
Another guy will tell ya he used 2 hi-torque servos in the tail and had to add lead in the tail to balance. But he doesn't indicate if he cut the firewall back or not.
I need specifics guys. PLEASE
How much did you move the firewall?
Did you put servos in the tail or not?
How many servos in the tail?
2 elevator servos? 1 rudder servo? 1 elevator servo? 1 rudder servo? Rudder is pull-pull on the CG? What? What did you do?
Did you use a mount from wacker engines? 2" or 3" mount?
PLEEEEEASE post specifics on this mod with the Ryobi 31cc engine. PLEEEEASE.
Thanks very much.
I've got a 4*120 kit coming in the mail right now.
Engine is going to be a Ryobi 31cc.
I have searched and done a lot of reading on this conversion. I just can't seem to find any really specific numbers.
One guy says he cut the firewall back and had to add lead to the tail---but he doesn't state if he used servos in the tail or not. Kinda useless to know how much he cut the firewall back when he doesn't indicate if he used servos in the tail or not.
Another guy will tell ya he used 2 hi-torque servos in the tail and had to add lead in the tail to balance. But he doesn't indicate if he cut the firewall back or not.
I need specifics guys. PLEASE

How much did you move the firewall?
Did you put servos in the tail or not?
How many servos in the tail?
2 elevator servos? 1 rudder servo? 1 elevator servo? 1 rudder servo? Rudder is pull-pull on the CG? What? What did you do?
Did you use a mount from wacker engines? 2" or 3" mount?
PLEEEEEASE post specifics on this mod with the Ryobi 31cc engine. PLEEEEASE.
Thanks very much.
LOL He couldnt stand it! My 2 posts got him thinking about that 120 and he just had to get one! Send the build pics!!!!!!!!!
#22
ORIGINAL: C_Heath
LOL He couldnt stand it! My 2 posts got him thinking about that 120 and he just had to get one! Send the build pics!!!!!!!!!
ORIGINAL: Rcpilet
I've got a 4*120 kit coming in the mail right now.
Engine is going to be a Ryobi 31cc.
I have searched and done a lot of reading on this conversion. I just can't seem to find any really specific numbers.
One guy says he cut the firewall back and had to add lead to the tail---but he doesn't state if he used servos in the tail or not. Kinda useless to know how much he cut the firewall back when he doesn't indicate if he used servos in the tail or not.
Another guy will tell ya he used 2 hi-torque servos in the tail and had to add lead in the tail to balance. But he doesn't indicate if he cut the firewall back or not.
I need specifics guys. PLEASE
How much did you move the firewall?
Did you put servos in the tail or not?
How many servos in the tail?
2 elevator servos? 1 rudder servo? 1 elevator servo? 1 rudder servo? Rudder is pull-pull on the CG? What? What did you do?
Did you use a mount from wacker engines? 2" or 3" mount?
PLEEEEEASE post specifics on this mod with the Ryobi 31cc engine. PLEEEEASE.
Thanks very much.
I've got a 4*120 kit coming in the mail right now.
Engine is going to be a Ryobi 31cc.
I have searched and done a lot of reading on this conversion. I just can't seem to find any really specific numbers.
One guy says he cut the firewall back and had to add lead to the tail---but he doesn't state if he used servos in the tail or not. Kinda useless to know how much he cut the firewall back when he doesn't indicate if he used servos in the tail or not.
Another guy will tell ya he used 2 hi-torque servos in the tail and had to add lead in the tail to balance. But he doesn't indicate if he cut the firewall back or not.
I need specifics guys. PLEASE

How much did you move the firewall?
Did you put servos in the tail or not?
How many servos in the tail?
2 elevator servos? 1 rudder servo? 1 elevator servo? 1 rudder servo? Rudder is pull-pull on the CG? What? What did you do?
Did you use a mount from wacker engines? 2" or 3" mount?
PLEEEEEASE post specifics on this mod with the Ryobi 31cc engine. PLEEEEASE.
Thanks very much.
LOL He couldnt stand it! My 2 posts got him thinking about that 120 and he just had to get one! Send the build pics!!!!!!!!!

I've had the 4*120 before and it's a great flying bird and an easy builder. You got me thinking about it and I just couldn't take it. Had to get one.

I've got the Ryobi parts and a couple older Ryobi engines here--but I'm waiting on the new Ryobi from harbor freight.
I might put a C&H ignition on it--just to lighten the engine. Kinda defeats the purpose of a cheap engine--but I don't care. I'll build it and fly it with the magneto first--but if I think it flies heavy, then I'll order the C&H unit.
I am thinking about covering it in fabric. Haven't done that before, and it's TOUGH stuff. It really takes a beating much better than plastic covering.
I'd like to modify the wings--and make it a 2-piece setup with aluminum tubes. My truck bed is only 73" long. It's a lot of work, and I don't know if I'll do it. But, I am seriously thinking about it.
Thanks C Heath. Ya got me interested in one of my old favorites again.

My wife just shakes her head and smiles.[:-]
#23
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From: dobson,
NC
My wife dont know!! [:-] Thats why men have BASEMENTS!!!!!! Ill head to my LHS tommorow to see if they have one
Im gonna PM you with some questions on building equipment
Later
Im gonna PM you with some questions on building equipment
Later
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From: mitchell,
SD
Rcpilet be careful,I know someone with a 4 star 120 and they covered it with that 21st century iron on fabric,if thats the stuff your thinking of using dont do it,anytime he got his plane above 1/2 throttle his wing would warp and twist because the fabric didnt have enough tensil strength like mono-kote,just a warning....Dustin



