raptorrx8

I've just installed a new zdz 80 rv-j into an extra 260. I took off the factory throttle arm and replaced it with a more suitable arm to take the usual ball joint connection. I took it outside for it's first engine run but found that while trying to prime the engine there was no fuel being sucked in. To check it I filled an open ended syringe with fuel and connected it direct to the carb via a fuel tube. On flipping the engine it still did'nt suck the fuel in. I've connected the fuel line from the tank to the brass nipple on the carb. The other nipple I assume is the breather? I've checked for any blockages but seems ok. I've previously installed a zdz 50 ng without any problems like this. Any ideas what the problem could be?

altavillan

My Feedback: (1)

If there is a second nipple on the fuel pump side of the carb it's to hook up a pulse line to opperate the fuel pump. take the carb off and see if the carb is drilled for a pulse port running through the carbs base that mounts to the engine. If the port is drilled then plug the nipple thats on the fuel pump cover plate. If it's not drilled you have two choices. Tap the crankcase or drill the port to operate through the carb mount plate.
If you have the pulse port drilled already, the extra nipple plugged, you might have the carb to engine gasket on wrong. You have to lign up the pulse port holes. Also a new carb can have the flappers stick closed on the fuel pump side, carefully remove the cover plate and remove the pump diaphram, then massage some oil into the diaphram to get it to start working. Reassemble and test.

Vismund

The Brass nipple IS the breather. Try conecting to the other one and you'll be fine.

raptorrx8

Some good comments there. I'll take another look at it when I get back from the grind. Cheers.