WRD compensating washers

[xcashewx]

so long story short, in arizona if your vehicle is 67' up you need to pass emissions. my pagoda was registered in 67' but the data sheet proved it to be a 66' so it no longer needed to go through emissions..
well, it had to have passed some how right? it put out .36% CO under load tests. and yes my decimal is correct.. and 1.17% CO at idle. with the idle mixture screw almost all the way to the right(rich). not good

i kept hearing about WRD compensation washers to richen or lean all fuel ranges, but when i took off my WRD, NO WASHERS!?

now my question is where, what, how many of these washers i need to run ideal. its a fairly new rebuilt IP, engine fresh as well. also, what is a good place to set my idle mixture screw at before fine tuning?

thanks for the help

[ja17]

Hello,

First of all make sure your main fuel filter is clean. If it is clogged, your fuel pressure and fuel volume will be low causing a lean condition. Make sure the other tune up items are up to specs. Make sure your engine linkages are set correctly.

Now make sure your WRD piston is not stuck. Make sure your barometric compensator has not failed. If so, your system will become overly lean.     If your lean condition still persists, adding a oval shim under the WRD or adding a round shim under the barometric compensator will richen the mixture at all speed ranges.  These shims come in  various thicknesses. Start out with something thin and add to it if you need .  You can do a temporary test by loosening, slightly,  the two screws holding the WRD onto the IP. AS you loosen, the WRD will rise, richening the mixture.  Another correct (but more involved) method to richen the mixture is to adjust the main rack screw (access through the back cover of the IP). Don't confuse this with the idle mixture thmb screw.   The main rack screw richens the mixture when turned counter clockwise. 

Don't jump right in and make radical changes on your injection pump.  Most likely some other item is causing the lean condition.

[xcashewx]

fuel tank was resealed, new main filter and tank screen. linkage and timing correct. . and it used to be fussy when cold and when it warmed up it would run fine. it runs better in the 3k+ rpm range.

the little screw on the side that moves the pin down on the WRD was turned about 1/4 way originally which i set back to  the "0" postion?. The piston and heat feeler both work flawlessly on the bench.

i forgot to mention, it runs really good cold, but as the temp reaches close to 145 degrees it starts running lean, backfires slighty when given gas, then quits

[ja17]

Hello,

I think I would first check by loosening the two screws which hold down the WRD on the IP. This should termporarily  richen the mixture enough to keep the engine running when warmed.  Next add some oval shims between the WRD and IP . This is quick and easy to put back. I suspect that since all oval shims are gone, someone might have incorrectly removed them?

In any case, you will need to check cold running after replacing the shims. Depending on what the results are, you may need to go back and check the barometric compensator and make adjustments possibly on the rack screw and or the idle thumb screw.

[xcashewx]

what thickness of washers should i use to start stacking the WRD up ?

[ja17]

Hello,

Try something in the .010" to .020" range to start with.