OTT

HELP!

I'm trying to get a new plane in the air, and I'm using a 3W75 that last flew last year. I've got everything ready to go, but when I try to test start it, it doesn't seem to be pulling fuel from the tank to the carb.

I just finished pulling & replacing all lines, hoping that I had a pinhole somewhere. After they were replaced, I tested the lines, and it seemed that everything was A-OK, but when I reattached everything, I still don't seem to be pulling gas into the carb. Shouldn't I be able to see the fuel being pulled up the fuel line into the carb? There's air in the line, approximately the last 1 1/2" or so, just before the carb, that doesn't seem to change when I spin the prop. I expected to be able to see the fuel flowing down the line and into the carb while spinning the prop.

I'm hoping to maiden this plane on Monday, but no-go until this issue is resolved.

Any help would be most welcome!

Thanks all,

Ott

rc bugman

My Feedback: (30)

Go to your local small engine shop and get a carb rebuild kit. Also check the screen in the carb.

Elson

Bass1

"Also check the screen in the carb"... As Mr. Bugman suggested,[sm=49_49.gif] That would be my first course of action.

DaddySam

My Feedback: (9)

I've found that the carb block needs to be sealed with a gasket type sealant. If you've pulled the carb and block, and put it back on without the sealant, this could be your problem. Locktite makes an "anaerobic" gasket maker which is what I've used and what I've been told 3W U.S. dealers use when assembling engines. I have two 3w-50's and both have to have the sealant in order to have adequate fuel pull.
Hope this helps.
Sam

ram3500-RCU

My Feedback: (221)

Have you had this carburetor apart? If not, I suspect some residue from sitting. Try priming the engine. If this works but she still won't stay running, Pull the plug and turn her over with the choke on and an electric starter till you get fuel. Then pinch the line and spin to dry out. Replace the plug and try again normally. If this doesn't work, then perhaps you take the carburetor off and clean, but then use the sealer mentioned already. I would view this as the last step. Usually, cleaning the screen is all it needs. The 3W55, 3W75 and a 3W80 are all part of my fleet of power plants. I love them all.

fytrjok

My Feedback: (2)

When you take the carb apart, make sure that the membrane with the little metal button is installed with the button engaged in the fork, otherwise no pumping will take place!