Hi Guys, It was suggested that I start a new post for my project so here it is. I am trying to get it to run for more than a few seconds. I am using a Walbro WT-644 and CH Ignition. Both are brand new. The 31cc, twin ring, Ryobi had been previously converted, (The Best Engines) but I have decided to swap out the Zama carb with the bigger bore Walbro and use the CH Ignition. The pulse hole is lined up but the carb does not seem to be pumping because it is not drawing fuel. When there is fuel in the carb. it starts with a few swings of the prop and runs strong for a few seconds ( until the gas in the carb. is used) then quits. I'll post pictures if someone will tell me how. I am new to this web site. Thanks for your help.

To post pics:

When you want to respond to a thread or put up some pics, you just hit the REPLY button. You already know how to do that because your posting on this board.

Now, just look at the bottom of the window after you type your message. There is a little line down there that says:

CLICK HERE TO UPLOAD IMAGES AND FILES

Just click that and you'll have a new window pop up. It will have a bunch of BROWSE buttons on the right side. Just click on the first BROWSE button and then search through your files on your harddrive. When you find the picture or file that you want to upload--just click it twice and it should load up into the BROWSE window. You can load multiple files by simply clicking on the next BROWSE button and search for the next picture or file. Double click your file and it will load up in the BROWSE window.

Now, at the bottom of that little window is a button that says OK. Just click OK and wait for your images to upload to the RCU server. If your on high speed internet--it only takes a few seconds. Dial up takes a little bit longer, especially if your uploading a bunch of big pictures. Then the window will say FILES UPLOADED SUCCESSFULLY and you click OK again.

Now you finish your message in the REPLY window and then hit the OK button to post your message and pics.

You can't just post pics without typing something in the window. If you have nothing to say, then just click a smiley face or something. There has to be something in the dialogue box in order to post it.

Are you using 2 lines to carb? And are you using primer? Make sure the line are hooked up correctly. Is the battery for ignition charged up good? Good Luck Capt,n

Okay, now I see it. Here are a couple of pictures. Thanks for your help. Also, a picture of my 1/4 scale, scratch built Loening M-8 which I am putting this engine in (instead of the FZ 120). The fuel line is on the right side (fuel pump) and the plugged return line is on the left side (fuel bulb). At least I think I have this right. Guess I'll take the carb. off and check that the pulse hole is clear and whatever else you guys think i should check.

I have had problems like this. Are you using the primimg bulb? I suppose not if the return line is plugged. Did your other carb have this setup? And are you using a choke plate, or manually choking it to start?

My guess is 1) pull the carb and clean it. If it is not pulling fuel, something is whacked inside, dirty, stiff, etc. or 2) check the gaskets on the carb/spacer/motor. If they are not sealing, you won't get it running past a little bit of throttle. Air leakage in these areas will kill it.

the problem is most certainly the carb.

br

Well guys, Thanks to all who have been very kind to respond my Ryobi is running! I am using the fuel bulb and it seems the better way to go since it kept me from flooding the engine. Just have to work on a new starting procedure when at the field. Once started it starts every time with a flip of the prop or two. Still need some break in time and I am running rich for now. Using a M/A 18-10 until I am satisified then I'll go to the 20-8 or 20-10. Oh, don't know what really fixed my problem but I just took everything apart and started from scratch. Reset the TDC and timing also. Cheers!

John,
Those prop sizes are much larger then is recomended for a 31cc Ryobi. Usually an 18x8 is the largest size used. A twenty inch can be used, but a 6 inch pitch is better suited to the engine.

Dave

Thanks Dave I will keep that in mind. I will know better once I get to tach. the rpms. I am not looking for high rpm's for the model the engine is being used in. Thrust is more important for the bigger prop. Still have to play around with it. I think this Walbro WT 644 carb. is making a big difference. I'll post again once I have had a chance to get the RPM's and have a little more run time on the engine.

John