View Full Version : Walbro 603 NRV P/N/availability
Anybody know where I can on-line shop for a Walbro 603 NRV? The NRV is located in the carb body and on checking the Walbro web site, it looks like I need a P/N 84-615.
I am told that Zenoah do not list this as a seperate part so buying from them sounds like a non - starter.
The defect is that the primer pump will not draw fuel through into the carby. The engine does still run okay (I think but I have changed it out anyway) but I am unhappy using this carby with it having a known defect.
Thanks,
Paul.
Assuming someone will be interested - I have managed to buy the NRV which is Walbro P/N 84-613-1 and have installed it. The carby now passes the leak check test that was originally used to confirm this defect.
If anyone wants to see the test procedue for this leak check then I can write it out here on the forum.
Paul.
WillJames
08-16-2004, 06:57 AM
I would really like to see it Paul. Glad you got it all straightened out!!
Thanks for sharing!! :)
Here it is:
'I`d be checking the "nozzle check valve", could have got a bit of dirt in
it. It`s a small one-way valve that is pressed into the body of the carb
underneath the primer diaphragm, best way to check it is to block off the
inlet with either a short bit of tube or a wet finger, pump the primer
bubble a few times to build a vacuum, the primer bubble should almost stay down after a few pumps'.
'Then try the same test again with both the H and L needles screwed all the
way in and see if there is a better vacuum, if it`s better then the valve is
suspect'!
The valve in question is a press fit into the body and a bit tricky to remove. I did it by inserting a small self tapping/sheet metal screw into the valve opening and after protecting the carb body, levered it out with a screw driver. A bit brutal but it worked!
The new valve is a easy fit by tapping it in with a small hammer and steel drift. Make sure you flush out all the debris fom the old valve before installing the new. Best to remove both mixture screws and spray some solvent down them.
Hope you never need this advice!
Paul.