Carb question after JD install

[parkcrf]

Installed the JD jet kit on my 04 CRF 450 tonight and of course I got everything back together and I tightened the main jet too much and it busted. I'll go to the shop tomorrow, I am assuming the 178 from the JD kit is a standard FCR main jet. It's the needles that are custom right?

There was a light film of dirt on the underside of the top piece of the carb. I cleaned it with WD-40. I am not sure how dirt got underneath the plate but it didn't seem dirty down to the top of the needle. Is this ok? How might it have happened? maybe my dealer didn't tighten it down enough for the rubber gasket to completely seat.

Anyway I had a dealer install my Factory 4 a while back and they rejetted. I pulled out a main jet like I have never seen before. It had a slot for a flatblade screwdriveand at first it was confusing me b/c I couldn't fit the 6mm socket over it. I pulled this out finally and realized the main was above it. The jet number on the face of the slotted piece was 155. That seems way to lean, is my dealer a complete idiot?

Has anyone seen a main jet like that before?

Thanks

[moto9]

I know the slow jets are slotted, not the mains.

yes, you use a standard 178 for the FCR carb.

The dirt under the top is coming through the air filter, not much you can do about that... I clean my carb once a month...and filter after every ride.

[Dovii]

I cleaned it with WD-40.

?

I'm sure it didn't do any harm, but next time use carb cleaner. It doesn't leave any residue.