BretChilcott

My Feedback: (1)

Guys - I have a G38 that I can not get it to draw fuel. I cleaned the carb, but no joy. Maybe there is something in the carb that I overlooked to clean?

When I prop it over either by hand or by spring starter, I can see the bubbles move back and forth in the fuel line, but they won't keep moving toward the carb. The tank is above the drive shaft plane so it is not too low.

Anybody have any ideas as what I should look for?

Thank you.

Bret C
Neodesha, KS

Rcpilot

My Feedback: (78)

Do you have 2 fuel lines going to the carb? One from the tank and one from the crankcase to the carb?

If so, it is possible you have the clunk line plugged into the wrong spot on the carb. Swap the lines around.

If that doesn't work, you probably have a worn pump diaphragm or possibly a dry pump diaphragm.

If the engine has sat for a long time, the pump may have gone completely dry. It will need to be primed again.

Priming procedure:
Remove both carb needles. Take them all the way out. Squirt a little shot of fuel in both holes. Let it soak in for a few minutes. Doit again. Another shot. Let it soak in.

Run the needles in until they stop. Back them both out 2 turns. Start and tune appropriately.

If priming doesn't work, you need a carb rebuild kit.
http://www.horizonhobby.com/Products...ProdID=ZEN3872

w8ye

My Feedback: (16)

Seeing the fuel move back and forth makes me think that the check valve in your pump is not seating

704hank

My Feedback: (1)

He could go out and buy a rebuild kit!
They are very cheap, and not hard to
do at all.[8D]
Hank
AMA# 674791

Rodney

Be sure to check the screen in the carb on the side with the single screw. If this is plugged, you will never get good fuel draw. If you google
(Walbro carb repair) you will find lots of advice along with illustrations.

BretChilcott

My Feedback: (1)

Yahoo! You guys are GREAT!

It was the check valve. It was gummy and sticking.

Now it is running. I still need to fine tune it and clean the screen that was mentioned above, but so far so good!

Also, I may just get the rebuild kit for it and install it before I ever mount the engine on the plane.

Thank you all for your help!

BTW - if you are interested in see construction pix of the 12' Snr Telemaster I am building, you can see it at.

http://www.flickr.com/photos/bretchi...7614314236834/

Keep flying!

Bret C

BretChilcott

My Feedback: (1)

Guys:

Just as a follow up to the thread for future people who may have the same problem with the G38. I did get the engine to run by cleaning the internal needle valve as described above. However the engine would only run for about 15 seconds. Each time it would stop I noticed there was air in the fuel line. So, also per a suggestion in this thread I rebuilt the carb. I walked to our local "Western Auto" store (yes Western Auto is out of business, but there are still a few dealer stores) carrying the carb. The owner of the store said, yes I have a kit for the carb. It cost a whole $8.99. It took only about 45 minutes to rebuild. And shezam! She runs like a new engine.

So, the moral of the story. If you pick up a gas engine that has been setting around don't mess around with it if it does not run perfect. Simply rebuild the carb. Also, make sure you pop the welch plug out and blow air through all the ports as you take it apart as well as spray it with carb cleaner.

Keep up the good chatter guys. You are providing modelers with a GREAT service.

Bret C

mtnflyer14

I also have a G-38, runs okay but I'm at 6600 feet here in Colorado Springs, and I'm wondering if there is another Walbro carburetor that would provide better performance than the stock (old) WTA-6A carb on the engine. I was told once that the Walbro WT-540 can be used on the GT-38 and that it has a larger diameter intake for more power. Any input or ideas from anyone? Thanks in advance.