Question re: WH-40 jets

[CWKboat]

Hi, I'm cleaning my WH-40 carbs in '87 XR-2, and I noticed in the bottom carburetor one of the main jets was missing. The jets are 0.78.

Would there be a mod reason a PO may have left out a main jet? I've had the engine for a few years and has always run fine other than sitting up past 2 years and needing a cleaning.

I plan to just order a 0.78 jet and install in the bottom carb. Was just wondering perhaps it would have been missing other an PO oversight perhaps with cleaning?

Has always ran fine at WOT, so I assume it would have just used a tick more fuel in that one cylinder?

Thanks for thoughts!

 

[Faztbullet]

Main jets are in the end of the drain screws...you likely looking at backdraft jets and they come from the factory missing.

 

[Dukedog]

wh40's originally had 80's for mains..............

 

[CWKboat]

Main jets are in the end of the drain screws...you likely looking at backdraft jets and they come from the factory missing.

Are those the same as the vent jets? I recall taking those out in my inline 6.

They are the 2 jets positioned side by side in the carb housing. Just found it odd that one carb has one missing so 5 total. In that case, guess I won't worry about it.

Thank you for helping get oriented.

 

[CWKboat]

wh40's originally had 80's for mains..............

Hmm..these did have 0.78 stamped on.

 

[Dukedog]

might have been "adjusted" by someone?.. production carb motors are always a tad on tha fat side from merc..

tha "vent" jets (side by side) are not a problem.. if they are there or not.. they are added for so called "fuel consumption" improvement.. but really do do much at all for it..........

 

[CWKboat]

might have been "adjusted" by someone?.. production carb motors are always a tad on tha fat side from merc..

tha "vent" jets (side by side) are not a problem.. if they are there or not.. they are added for so called "fuel consumption" improvement.. but really do do much at all for it..........

It is supposedly an '87 XR2. I couldn't figure out rhyme or reason for what carbs it was supposed to have, but does have Wh-40 stamped on them.

 

[Dukedog]

40's are right.. with merc ya never know about "anything production" 100%!!! that carb "body" is used in several different motors with nothing but jet size difference.. thats why tha wh number is stamped "after tha carb is built"..

pm sent.