Topic: CB750 K8 Need carb help please!!!

[gnarlycharlie4u]

Those would be the needle jets.

HA! I totally missed this part. Uh yeah, if you're missing the needle jets you've got a problem and certainly explains why there's fuel coming up around the needle at idle.

They're easy enough to press out but BE CAREFUL putting them in your carbs. You can screw up and get them in crooked. Then it's a total mess.
To replace them:

• I suggest putting a punch or something similarly thin and pointed down from the top (where the slide goes) through that hole where the needle jet goes.
  
• Flip the carb over and slide the needle jet onto the punch.
• Screw in the emulsion tube lightly.
• Flip the carb back over(upright) and use the punch to keep the needle jet centered while you screw in the emulsion tube the rest of the way.
• ^^this will press the needle jet back in with even force so you don't mess up the hole. be careful not to use too much force if it feels stuck, you can strip out the emulsion tube threads.

Good luck!

[JustinC.]

PROBLEM SOLVED!!!!

I wanted to thank everyone that helped me out with this.  I know a couple people are going to say "I told ya so" when I tell you what it was:

Well being new to these carbs and having never taken them apart before I did not notice the problem.
Sometime in this bikes long life a previous owner must have thought it was a good idea to drill out the pilot jets.  I never knew that this was the issue until I got my eBay carbs and pulled them apart.  I noticed right away how small the hole was in the eBay pilot jets.  So I cleaned the new to me eBay carbs well, reset float height, bench synced, and threw them on.

Cracked the throttle a few times, fuel was squirting from each accelerator, fulled the choke, and fired it.
I'm out about 2 turns on my mixture screws and it sounds great, nice and crisp, not more loading up.

So, now that I'm a self taught and self proclaimed carb "professional" I'm going to throw some new pilots in my original carbs as they're super clean inside and out and polished, then clean the eBay carbs and polish them as well.

If anyone needs a known good set of PD42B's let me know.

Oh, the hole in my original pilots was drilled to about 1/16".  The new pilots are so small I can only fit my smallest wire cleaner from the K&L cleaner set through them.

Thanks again for all the help!

[gnarlycharlie4u]

I'm interested in the PD42's if you're getting rid of them. I don't need them for anything in particular at the moment, since all my bikes are in pieces, but I might make use of them down the road.

If you want to PM me with a price then hopefully we can work something out.

[brewsky]

Those would be the needle jets.

HA! I totally missed this part. Uh yeah, if you're missing the needle jets you've got a problem and certainly explains why there's fuel coming up around the needle at idle.

They're easy enough to press out but BE CAREFUL putting them in your carbs. You can screw up and get them in crooked. Then it's a total mess.
To replace them:

• I suggest putting a punch or something similarly thin and pointed down from the top (where the slide goes) through that hole where the needle jet goes.
  
• Flip the carb over and slide the needle jet onto the punch.
• Screw in the emulsion tube lightly.
• Flip the carb back over(upright) and use the punch to keep the needle jet centered while you screw in the emulsion tube the rest of the way.
• ^^this will press the needle jet back in with even force so you don't mess up the hole. be careful not to use too much force if it feels stuck, you can strip out the emulsion tube threads.

Good luck!

Bamboo bar-b-que skewers work well as removal/insertion tool....

[BobbyR]

Job well done!!!!!!!!!!