RE: Plug gap
[quote]So, in a very high compression Diesel engine the plug gap should be set to zero? Sincerely, SPACEWORM [/quote] [quote]My diesel doesn't have a spark plug [/quote] Damn thats funny. Anyhow I loaded up and went out to the airfield today. the engine and ignition didnt miss a lick at the .019 gap over several flights. This ignition may be able to handle the larger gap but for some reason the particular unit I have really likes the .019. Im gona run it at that and problem solved lol
Posted on: 6/13/2010 10:22 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9801052

RE: Plug gap
[quote]I am thinking it is because you have a bigger spark with a larger plug gap that you want .025 inch instead of .019 or.022. Right? But what is the problem if the engine runs better (read OK) at a plug gap of .019? Any downsides? Thanks. [/quote] That is true till you add in pressure. when you increase the pressure of the air fuel mix that the spark has to jump it increases the resistance and in effect you have a smaller spark. to offset the increased resistance one would decrease the gap that the spark has to jump across. so one could say that the size of spark is inversly proportional to the pressure at which it has to jump a set gap.
Posted on: 6/12/2010 10:48 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9799198

RE: Plug gap
I guess I could start opening up the gap .001 at a time and see where the problem comes back at. I wonder if i got a weak box or if the high compression that has been built into this engine could afffect this. I know it gets harder for the spark to jump the gap under pressure. I will play with it tommorow.
Posted on: 6/12/2010 9:11 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9799005

Plug gap
Ok I know this seems to be a pretty basic subject and seems wouldnt need much discusion here. Anyhow my stock ryobi ignition i was running a plug gap of about .025. It ran fine with that gap. I then bought the rcexcel ignition and installed it. the thing runs just great till full throttle when it would experience momentary cutting out in ignition. I know this is not a carb issue as I put the stock ignition back on and it ran just fine. Ok so sitting in my garage thinking on it really hard I decided to play with the plug gap. I first went larger which made the problem all the worse so i knew I was on to something. I then set the gap down to .019 and it stopped having the misfire at full throttle. I did not get to run it to long to confirm this as my wife came out to the garage with the old why are you messing with that look when you got other chores to do. I will go back out and run it some more tonight or tommorow morning to confirm this. anyhow What gap are you guys running on your stock or electronic ignition. I read the rcexcel instructions again and it just didnt say anything about plug gap. My findings so far are that the electronic ignition dosent much care for to wide a gap or at least the stock ryobi gap.
Posted on: 6/12/2010 7:09 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9798812

RE: Ryobi 31cc flywheel
When you get a new flywheel you got to remember not all ryobi flywheels are the same. there is a narrow key and a wide key flywheel. one uses the half moon key and the other type has the key cast into the flywheel. also there are flywheels made by phelon and some mace by walbro. why is that important to note? Because they have different timming in them depending on who made them and you need the coil that matches that timming. so now the question is: What flywheel do you have?????
Posted on: 5/19/2010 8:03 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9745574

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
Oh yea i also flew my ultra spad stick yesterday. my ignition seems to have an intermittent point where it cuts out every so often for a second or two. dosent seem to affect performance but it is damn annoying. I really dont think it is carburation problems. it could be i guess. maybee its not getting enough fuel. oh yea it seems it only does it at full throttle.
Posted on: 5/18/2010 9:48 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9741881

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
[quote]The only thing I see with your flywheel, that may be a concern. It appears that you buffed the center of the flywheel. Thats the area that your prop adapter will ride. If that area is not true it may cause your prop adapter to not run true and vibration may result. [/quote] Yea if you sanded the center section your definatly gona need to true it up now. I dont know what kind of prop adapter your using but they one I am using is the stud that screws onto the shaft as mine is a short shaft engine. when it comes up tight against the flywheel if it is not concentric it will push the shaft of to one side so when it rotates it will look like the shaft has a wobble to it. We found that merely chucking up the flywhel in a lathe and cutting the fins of and facing the center section did not ensure a concentric cut either. this is due to the fact that the back of the casting where is sets in the chuck is not concentric to the tapered hole. Ok so what we did to get everything back in line was to take an old crankshaft and knock the counerweights off the shaft. what you have left is a shaft with the taper on one end where theflywheel mounts. install the flywheel on the shaft then chuck it up in the lathe. leave it sticking out far enough where you can face off the back side of the flywheel. once the backside is faced off the shaft can be removed and the flywheel chucked up in the lathe with the back up against the chuck face and all will be concentric when you face off the fins and center section of the flywheel. I undestand you dont have a lathe. you still may need to have this done. check the local community college. they may have a machinist program where they can do that for you. usually it is no charge as they just need the practice.
Posted on: 5/18/2010 9:45 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9741877

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
I got my new ignition from southeast rc engines and got it in the plane today. night and day difference from ordering the xyz ignition. you get so much more from southeast rc engines. not only do you get the ignition box and the sensor but you also get a nice little assortment of extras you dont get with the xyz ignition. It may just be me but I swear it runs better also. it starts so easy, just one flip and whammo its running and idles great. I was getting a little cutting out at high rpms and then i realized the plug socket was not on all the way. a small adjustment there and this thing sings. THANKS SO MUCH Southeat RC Engines I also like knowing it has a warranty and tech support I can talk to. The recipt was even hand signed. nice to see that level of customer appreciation.
Posted on: 5/15/2010 10:44 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9736351

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
Its darn good to be back. I have been so busy i just havent had the time to do anything fun. It has slowed down just enough to be able to dust off some planes and get back to the field. Still not going to do any R&D at this time. Just dont have the time still. I really want to get back to doing some combat flying also. I got a new combat plane to build up. HMMMMM ryobi combat anyone????
Posted on: 5/12/2010 11:08 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9730243

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
Damn i cant belive this thread is still going. I cant remeber the last time i posted. anyhow i finally ordered my new electronic ignition. i am getting it from southearst rc engines and they got this cool tach add on. man thats gona be sweet and take all the guess work out of using them crappy hand held units. I should have my ultra spad stick ready to go again in a week or two. sorry i wont be doing any more R&D but im glad to see you all continuing on
Posted on: 5/11/2010 9:37 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9727357

RE: Engines with two rings???
I have a 40cc Echo blower engine that has 3 rings....... imagine 3 Bowman rings..... you really only need one and may be much better than 3 but i really hate to get into all that again. i dont care how many rings you got. more rings dont garuntee a good seal. you could have 4 rings with a worse seal than a single ring with a great seal. condition of the parts is everything and the only way to know how good a seal you have is with a leakdown testor. man i really hate to go into that again.
Posted on: 8/26/2009 5:56 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9047452

RE: Homelite 33cc
the silicone line looked like it was coming from the fuel tank in the plane and thats why it looked like it was backwards. I would get rid of the primer bulb in your line and just go straight gas line. take a syringe and hook it to you primer port with a bit of fuel line. use it to pull fuel into the carb then force a small amount back into the carb to prime and it should start pretty easy then. remove syringe and block port.
Posted on: 7/7/2009 7:11 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8912840

RE: Homelite 33cc
I can see from the pic that you got the fuel lines on backwards. your in line is on the primer port and the primer line is on the inlet. also im not sure how long that silicon fuel line is gona last with gas if it is in fact silicone. but hey dont take my word for it im sure there are far smarter and far more qualified people on here than I.
Posted on: 7/6/2009 10:07 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8912024

RE: 28 degree magnet placement?
you all might find this hard to belive but i got nothing to say on this subject. Im pretty much done with the forum altogether lol.
Posted on: 6/22/2009 9:12 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8870914

RE: xyz cdi
OMG this is just unreal. I just saw the video. I will concede that you do seem to have a pretty good feel on finding TDC with the slop method. Still this is not garunteed accurate. Funny how you back it up with the piston stop method which is the only true way to know for sure. Granted i will give it to you that you do seem to be pretty accurate with your method but still it is not garunteed. I would not have belived it had i not seen it. michal wood replies. [quote]what are all the parts used to make a piston stop? the way you did that was so super easy thanks michael [/quote] Which is what i been working so hard to try to get you all to understand. Can not one of you bite your pride and concede to me that the piston stop method is absolutly accurate easy to do and not expensive and my time and effort and frustration was worth something???? I just dont understand how you can work so hard to discredit my info then steal my idea to make a video using and describing the very methods i use and describe and now suddenly their right?
Posted on: 6/19/2009 1:37 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8864726

RE: xyz cdi
No captn once again you misunderstand me. i feel like the song Oh god why should i be so misunderstood. i was reffering to my idea of making a video. anhow i do regreat saying that as i have since talked to milton on the phone. He is a super nice guy and very knowlegeable. i hope the two of us has reached some sort of understanding on the points and methods that we were trying to convey on this forum and i feel at this point there is no ill will on either part. thank god there is now a video so there is a visual representation of this method as describing it here just dosent seem to work. In fact i invite any of you to call me so we can hopefully put any of this behind us and clear anything up. pm me and i will give you my number.
Posted on: 6/19/2009 1:24 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8864871

RE: xyz cdi
Well i guess well just have to chaulk it up as a case of pure magic LOL.Words removed by moderator
Posted on: 6/19/2009 2:33 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8836499

RE: Homelite 33cc
Man i would love to do that but if i had to write you a check for that amount right now it would bounce lol. Im that bad off at the moment.
Posted on: 6/16/2009 3:25 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8856936

RE: xyz cdi
Yea I really would like to do a video on it. I think i know who can help me put it all together but i need a new ignition box.
Posted on: 6/16/2009 3:23 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8856932

RE: Homelite 33cc
Avi8tor i think it was you that told me tht the number in the venturi of a carb is the venturi size in 64ths. Man I got to thank you for that. it makes carb identification so easy. I dont come across many chain saw engines at the engine shop bin. i did score a 46 cc tht im hanging onto lol. I do hope i can get lucky like you and score one of these. i really like how they have the carb on the side. the ryobis are such a pain with them on the rear.
Posted on: 6/16/2009 11:44 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8856472

RE: xyz cdi
[quote]TDC Piston stop. setup degree wheel and pointer. Install P.S .turn engine until the piston hits the stop, record number of degrees. Turn engine other way until the piston hits the stop. record number. Add numbers, divide by 2. With the piston against the stop, fudge the degree wheel until the magic number is under the pointer. To validate your math turn the engine the other way until it hits the stop. The degrees should be the same. Of course one will be BTDC and the other will be ATDC Example 15 deg BTDC and 35 deg ATDC added = 50 degrees, divide by 2 = 25 degrees. Set the degree wheel so that the pointer reads 25 degrees BTDC & ATDC when the piston is against the stop. Using a piston stop is more accurate than a dial indicator simply because it will load the Boca Bearings has the most comprehensive RC Bearing search engine on the internet! bearings and remove ALL the slack from them. On a simple single its super easy to use. . On a multi cylinder with heads and accessories on its a major PIA as Battle Axe Kits from TreneffRC are the finest Combat kits available! combat pilot explained A dowel can shift, get a long reach spark plug and make a piston stop. WORD OF WARNING IF YOU FINALLGET IT RIGHT, DONT tell anybody in your club. If you brag about being able to time an engine you will endup timing everybody's engine anytime it burps. Make every body think its Rocket Science, even though its so simple after a few times. [/quote] Terry i think your right when you say its more accurate then a dial indicator. I think the method describe above is the best way ive heard it described. I really have to thank avi8tor for turning me on to the piston stop. Its so freaking simple lol.
Posted on: 6/16/2009 11:32 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8856432

RE: xyz cdi
Michael did you finally use and understand the piston stop method? If you did can you now see why using a dowl to try and feel the piston dead spot would not work real accurate. Its not that hard to make a piston stop. Its so simple once you understand it. Sounds like you got it right this time if your engine is running that good. Isnt it nice to know your dead on where it should be and you dont have to guess and hand tune it? Like I say this subject has been discussed to death on here. I just dont understand why it is so hard to understand when the process is so simple. I think if I can afford to get another ignition box and i can find someone to video and edit me, I will make a video of this process and place it on youtube. It really seems there needs to be an instructional video of this.
Posted on: 6/16/2009 11:24 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8856404

RE: Homelite 33cc
Wow all stripped down it looks to be a pretty sharp engine. With the performane numbers you guys are getting out of them it makes me mad im so damn broke or i would go get one of these. Maybee i will get luck and find one in the recycle bin at the lawnmower shop. What size carb are you guys using to get the 8200 rpm on an 18-8 prop?
Posted on: 6/16/2009 12:10 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8855493

RE: Homelite 33cc
Post a picture of it. I am wondering how it compares to the poulan 32 cc which i have 3 of and am considering using that for my next project.
Posted on: 6/13/2009 9:45 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8849890

RE: xyz cdi
how are you finding tdc. i really like the method avi8tor posted but havent had a chance to try it yet. you must be at true tdc to be accurate.
Posted on: 6/12/2009 4:04 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8847225

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
Jack i just realized what you were talking about. you are using a single cell lipo and thats whay you reffered to the lower voltage. duh sometimes i suprise myself lol.
Posted on: 6/12/2009 10:34 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8846560

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
Im not sure where it came from. I bought it second hand from a friend of mine. he gets his somewhere online. i cant remeber the name of it but i know its not cheapbatterypacks.com I will ask him next time i talk to him.
Posted on: 6/12/2009 10:32 AM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8846553

RE: xyz cdi
[quote]If the timing is to far advanced, like 35 + deg BTDC then it may develop a HS speed miss, almost like it is to rich. BUT you can't tune it out using the carb needles. [/quote] That would be as not set dead on 28 degrees right???? Ok lets say just for argument sake that it is set spot on 28 degrees just like its supposed to be. At that point wouldnt you look at the carb???? thanks for the info Ralph
Posted on: 6/11/2009 10:57 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8845656

RE: xyz cdi
I do understand that it is a new carb. I dont think that necassarily garuntees that the diapram is set right. also i got no way of knowing that your actually set to 28 deg. al i can do is take your word for it. I dont know if the best timming is variable per engine so i was asking someone that has set up way more of them than I as i have only set up one and it ran spot on at 28 degree. I am very certian i have or should say had before it crapped out, mine set precicely at 28 degrees.
Posted on: 6/11/2009 10:43 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8845613

RE: another darn ryobi post (ryobi performance modification, analysis and comparison)
I got a chance to fly my plane with the ryobi again today after i put the stock ignition back on. it didnt add back much weight but the thing i didnt figure in was the weight was moved furtuther out to the nose so now it is nose heavy. I may have to go back with a electronic again for the weight distribution. Also my carb was so worn out from all the testing that i decided to go ahead and and install one of the wt577s i got on ebay. while convering it I noticed this carb actually has an acellerator pump that is run off of the throttle shaft. this carb lends itself well to conversion and runs great [quote]I use a single cell 1800 mah LiPoly battery to power my CHXL (essentially an RCEXL) ignition. It weighs a fraction of the weight of a NIXX battery and it runs fine at the lower voltage. Check out the CH ignition web site for tests that Bill has done on ignition function vs. supply battery voltage. [/quote] Jack are you sugesting that maybee my battery voltage was not adequate? I had wondered that myself and checked my battery several times and the voltage was 5.95-5.97 every time i checked. I am using a 1800 mah nicad battery
Posted on: 6/11/2009 10:31 PM by Author "combatpilot" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8845582