Help is appreciated with my first ryobi 725. Nothing I seem to do will start the engine(not even a cough).

I can get a spark and I can see full fuel flowing into the carb. The brass line next to the needle valves is sealed. I've tried the needles at 1 turn out and/or 1 1/2 turns out. I've primed with fuel and tried to start it with some choke. My throttle is set at 1/4 - 1/3. I'm trying to start it with a power drill set on reverse.

My results....Nada.

Unfortunately I did not run my ryobi 725 in weed whacker mode before I started to take it apart so I can't tell if there is something seriously wrong with it. My guess is I'm donign something wrong.

Thanks for any help.

I would make sure there are no air leaks on the carb mounting and that the pulse hole is clear and aligned. ( I had to make a spacer for the carb thus two gaskets.) Plug gap .025" and coil to rotor .010" (business card) between pick-ups and magnets and tighten. Still no go, then check the diaphrams inside carb and the screen filter under the cover with single center screw. Clean with cheap generic sray carb cleaner.

You did not mention if the engine was new or used when you acquired it?

Thanks, I'll give that all try. The instruction manual for the 725 says to use a .020 gap-is the .025 the actual gap size?
Also, since I can see a spark, doesn't that mean that my plug cap and coil to rotor gap are correct?
The engine is a factory reconditioned model from Habor Freight.

SB

You are correct. I have never seen the owner's manual.
Ryobi data source: http://www.ryobioutdoor.com/FAQ.jsp#13
I'm going to try a regap on one of mine that starts hard..

Remove the plug and squirt a little gas in the cylinder, replace plug and try to start. If it fires, shoot carb or reed valve trouble.
Good luck, red

Here is the latest:
With outthe spark plug in the cylinder I can get a spark (when the prop is really moving). When I place a plug in the cylinder and rev up the prop - get nothing. The fatest method I have for spinning the prop is with an AC drill directly on the prop nut. When I tried a starter or rope, the RPMs drop even more.

I'm not sure this is helpful, but the compression seems quite high. Is it possible that my high compression is keeping me from getting the RPMs I need to get a spark? Any advice?

Thanks,

SB

Yep, I have had to loosen the plug and then spin with starter. It would start and run....tightening the plug with engine running is dangerous even with a shortened open-end wrench.
View this before you get your fingers and a wrench on the plug: http://www.piratas-aereos.netfirms.com/accidentes.htm NOT A PRETTY BUNCH OF PICS.

It too big of a pain doing that with the plane on a stand with a helper. Besides I strive to have them reliable and function properly. It now has a CH Ign on it.

Mike:
Did you ever find that after you ran the engine with the glowplug untightened that it warmed it up and then subsequent starts were easier?
I sure as hell would not want to touch that beast while the engine is running? How easy does the engine start now with the ignition system on it and what do you use to start it?

SB

One of the problems I ran into was fuel draw. I was told it didnt matter too much but found that on my perticular engine it did. It would run fine on the test stand, but wouldnt start in the plane. I lifted the tail and choked it a few seconds with the starter, ignition off. Dropped the tail back to the ground, ignition on and it starts right up. Initially I had a lot of problems getting the carb set. I finally reset both needles to 1 1/2 turns to get it started and just tuned it like I would a glow engine. Back and forth until I was satisfied. My sympton was similar to yours. Just couldnt get it to start. The carb reset got me close. Rock solid reliable now and starts easily using my priming method. This is a 6 year old worn out ryobi.
Edwin

sboxer : don't make this into a harder problem than it is, most magneto sparked engines require a minimum number of rpm's before they will produce a spark; with your sparkplug removed there is no compression for your drill to overcome, with it installed your rpm's drop, probably no spark, as ryobi engines require 300-400 rpm cranking speed before spark is produced. That being said, be sure your fuel line is on the correct inlet tube,one tube is for priming and other is fuel inlet. Tube w/90 degree bend is fuel inlet,straight tube must be blocked off if not using primer bulb good luck cal .45 acp

I was able to get my Ryobi up and running by doing two things:

1)I used a pair of 8Cell Nicad packs in series from an old ZAGI (finally found a use for them) to power up my el cheapo hobbico HD starter. Since my spinner is 3" and the hobbico is for much smaller spinners I placed a 1" piece of a garbage disposal rubber pipe ($3 at home depot) and clamped it to the outside of the starter's cone. That slips over the spinner nicely.

2) I also ever so slightly loosened the spark plug. The engine started up on the first try. After letting it warm up for a minute, I killed the motor and tightened up the plug and restarted the motor.

My high and low end valves were both out 1.5 turns.

At this point, I'm going to play with this beast and run some gas through it and get it ready for my big pink.

Thanks for everyone's help.
SB

sboxer-
with a CH Ignition ($119) you can start it on the first or second flip with a gloved hand. Starts VERY easy. Remove flywheel and magneto, add battery pack and thats it.

Thanks Dirtypool-I may be headed in that direction. It seems safer too.

For the moment, the weather is too cold to even think about flying.

SB

I agree that your problem is lack of RPM. Mine starts great with an electric starter conected to a fully charged 12 volt battery. It will not spark by hand propping. Best of luck!

Phil

Hi Dirtypool,

Who sells them for $119?? How much better does is run with the electronic ignition? I was thinking about converting to it. I fly in front of the house at our 3000' airstrip and try to keep the noise level to a minimum so the neighbors don't *****. Which is the best Ryobi muffler for noise vs. performance?

Thanks for all the help!

Phil