So, it is possible for the engine to run on just the low speed needle if it is open too far? I will go back and start over. But I think I will take the evening off tonight though. Thanks for all the help.

Jim

Yes. And Batguy is right too. If you are running the stock muffler, you really need to gut it and also provide more outlet area.

AV8TOR

The muffler I am running has been gutted and a 1/2" x 1" hole cut in it. So should have plenty of breathing room. Looks like if I want to do any more adjusting, I'll have to do it tonight before Ike hits. Looks like rain for the next 3 days. This has been the wettest summer on record for us.

Jim

How about a new one http://www.homedepot.com/webapp/wcs/...54&marketID=67 Take a look Capt,n

Dang captinjohn-it's raining Ryobi long blocks [X(]-too bad some aftermarket genius hasn't come up with a better reed valve for these. They're calling them 30cc. wunder if it's a different engine or still the 31?

That 30cc Ryobi looks to be a Homelite engine...with a newer type of carburator. Looks real easy to work on and mount to a airplane!!! Capt,n

I believe they are the same as the Homelite 30 just rebadged as a ryobi

Sounds like a good unit for the $$ http://www.homedepot.com/webapp/wcs/...egoryID=530582 Capt,n

Gave it another try last night. Set needles back to 2 turns open apiece. Choked engine, set throttle to WOT and flipped until the engine sputtered. Open choke and flip, engine starts and runs full blast for about a second or two. Just long enough to burn the fuel from being choked. Choke again. Same results. At about this time, it stopped firing at all. Discovered that my hall sensor had come loose. I had used epoxy to glue it to a hose clamp then mounted to crankcase. Epoxy broke loose. I had debated on drilling and tapping the crankcase but did not want to remove the crankshaft to do it. Decided to give the epoxy one more try. So set it up to cure overnight.

In the meantime, I noticed that my throttle plate had not been opening all the way. When I get to 1/2 on my transmitter, the servo had reached its end point and the throttle was only about 1/2 to 3/4 open. I did not get the servo arm back in the right place. Was in too big of a hurry. So when I was trying to adjust the H needle last time and was not getting any response it was because the throttle was not fully open. My fault again. [:@] Problem is on the Ryobi, the throttle arm and plate are hidden between the muffler and carb and is hard to see. To say the least, I spent some time last night making sure it was set correctly and that I got full travel on the throttle. Now if Ike will just hold off a little longer, I will try it again tonight. If not, rain until Monday.

Jim

How is your ignition timing set up at???? Maybe is your timing!!!!

Timing is set at 28 Degrees BTD. I have had it running at this timing before. Back when I started this thread, the problem I had was that I could not lean it out enough at WOT. All of this effort was to fix that. All started when I swapped carbs and back plates. Timing should still be ok.

Jim

You said opened choke all the way after full choke 1st flip..?? Up here in the great frozen north we usually keep full choke until start then quick about 2/3, then 1/2 until it warms up a little, then open. 1/2 choke like 30 seconds to a minute depending on how cold [&:]it is. High speed usually starts a 1 1/2 out, low speed 1/2 to 1. How's the compression on this (sorry if you stated before and I missed it. This is getting to be long thread)even though the rings are new? Anyway stay safe down there in TX.

Since what is left of Ike is blowing hard outside right now, I decided to pull the carb off and go through it. I bought a repair kit yesterday. First thing I checked is the pump. All good. Next I took the regulator cover off and discovered that a too thick gasket was used under the diagphram. Next I pulled the needle out and found that the red was showing on the needle. Needs replacing. Then I shot carb cleaner through the needle openings and found that I had good fuel flow from the idle and high speed ports. This carb has the membrane check valve and it seemed to be working ok. It would bet wet but not allow a bunch of cleaner through when cleaner was shot through the needle ports. So I put a new needle in. Changed out the gasket on the diagphram. And then put back on the carb back on the engine. It should be good to go now. I think part of my problem was the bad needle and the wrong gasket on the diagphram. I also read on a web article that the diagphram should go on the body first then the gasket then the cover. So that is the way I did it. Made double sure the throttle was set up properly on the servo. Ike looks like will be out of the area by tommorrow afternoon so hope to try again then. I have learned a lot about how these carbs work over the last week. If I had known sooner, I might have saved myself some trouble. Most of it was my own fault.

Jim

I know I shouldn't say this but that was going to be my second guest, the metering needle being stuck or to open, because you mentioned that it would only run after choking then it would sotp, that means no fuel through the metering needle, and then when the metering lever that lifts the needle is to high you thend to overflood the carb and thus the high needle is hard to set. I hope that the changes that you did work out for your engine. Good luck

Ike cleared out early this morning now we have a beautiful day here in East Texas. Too windy to fly but just right for engine testing. Gave it another shot. Same thing, can not get a reliable idle or full speed. After spending a full tank adjusting, I shut it down to think for a while.

While watching the pregame show, only thing I could think of is maybe ignition. I have another ignition module so I was thinking that I might try it. But then I thought, it just seems like the engine can not draw fuel properly. What could cause that. I know it is not the carb because I have gone through it completely. Then I thought, also before I started all this, I was having a problem with interference so bought a resistor plug. The plug I bought was a RDJ8Y. The original plug was a DJ7Y. Pulled the plug out and compared it to the DJ7Y. The 8 does not go into the cylinder as far. So I thought maybe the 8 was letting the compression down by not sticking as far into the cylinder. So I stuck the 7 back in.

Fueled it back up and headed out into the yard. Needless to say, It improved immediatly. I could adjust the low speed needle to get a reliable idle and good transition. However, the engine would peak just before hitting full throttle. Keeping in mind that I do not have a throttle stop for WOT with the lever swapped end to end, I adjusted the end point on transmitter until the engine peaked at the same time the stick reached full on my transmitter. Engine is running perfectly now but now the glitching problem is back. Will have to order me a RDJ7Y plug to get rid of the RFI glitching.

I tached the engine with my Tower tach. Dont know how accurate it is but the engine sounded like it was hitting peak rpms. Using an APC 17x10 prop, I tached 6700 rpms at wot. and idle was at 2400 rpm. I grabbed the tail of the airplane to see how hard the engine was pulling and it felt like it had lots of pull. I dont know if this prop loads the engine more than the benchmark prop of 18x6. I have read that 18x6 should do around 7k to 7400 rpms. How does this compare in load to the 17x10? Dont have enough ground clearance to use an 18" prop on this plane.

Anyway, it felt good to get the engine running properly after struggling with it for over a week. Eventhough I still cant fly it until I get that resistor plug.


Jim

Jim, it sounds good that you got your Ryobi running good. If you can find a metal shielded cap for plug and use some metal braid over the spark plug wire...that may be worth doing to avoid interference. Just a Idea. I have seen those caps on smaller imports at junk yards. The braid you can get off CO-AX. Capt,n

Picked up a couple of resistor plugs at our local auto parts store. So ready to fly now. However, planning on going to the B-17 fly-in at Bomber Field this weekend. Apparantly Ike did not cancel the show.

Jim

Ok, finally got to put the Ryobi in the air yesterday. On my 14 lb Sig 4 star 120, it flew the model flawlessly for 5 completely satisfying flights. Plenty of power on the APC 17x10. Would probably be better with a 18x8 but not enough prop clearance. She started easier than my Zenoah G20 and the XYZ ignition performed perfectly. A very fulfilling day at the flying field. Nice after all the heck I had getting it done. Especially since most of it was from my own ignorance. Well that is how we learn and advance in this wonderful hobby.

I was surprised at how much power it had. At full throttle and level flight I could ease her straight up and could go a long way before she ran out of oomph. Outside loops were a breeze and inside loops could be done easily at half throttle. Only problem I had was slowing it down enough to land. Even at idle, that 17x10 prop was pulling pretty hard. It would sit still in the grass but once on the asphalt she wanted to go.

It turned out to be a great conversion.

How do you guys feel about this engine on a 15 lb 90" Ryan STA? Would it have enough power for it?

Jim

I would say it would probably fly it fine. Not unlimited aerobatics, but I don't think it would be a dog either. 18 x 8 prop, and I recommend APC.

AV8TOR

Jim, Try a 3 blade prop with a lower pitch for slower landings. I hear 3 blade props tend to be smoother also! Best Regards, Capt,n