Most times the carbs just need cleaning. You can try 'Seafoam ' or you can get someone Like Flyin 900 to ultrasonically clean it.

 

If I can do it you can too. Pretty simple! Slow and careful did the trick. I found that the idle jets where both clogged. After cleaning, I ended up installing new jets from carbjetkits.com (125 main / 40 idle / 2 shim each) since I was planning on adding pod filters and emgo mufflers.

 

Did you only get 1 main jet set or did you get the second and third set as well?

 

Or you can buy a can of Berrymans Chem Dip, disassemble and soak only the metal parts in it for 48 hours, rinse with water, and blow out all the openings with high pressure air. The float valve has a rubber tip so it doesn't go in, as well as the plastic float and all gaskets and O-rings. This diagram shows where the plastic and rubber things are. 1987 Honda CMX450C A CARBURETOR | Cheap Cycle Parts

 

I'm having a hard time getting mine off my 450. I can't push or pull the breather box out of the way even after unbolting it.

red 87 rebel 450c

 

If you loosen the box remove the hoses that are between the carbs and box the carbs come out easier

 

If it's like the 250, you don't remove the air box, just slide the left and right air tubes back into the box. Those are parts 7 & 8 here: 1987 Honda CMX450C A AIR CLEANER | Cheap Cycle Parts

 

I remember when I put mine back on, it was pain! I had several cuts and bruises from removing carbs.. You need to wiggle it a bit.

 

I recently removed my airbox and carbs. I dont remember it being hard to take off.

 

If you are going to do it properly then the bank should be broken down completely and all parts removed from the body and then either soaked or Ultrasonically cleaned. There is no way to remove the inner air cut diaphragm unless you are really good with both carbs still attached together and then there is chemical residue left in there from a soaking them.

Take pictures too, as the parts fiche doesn't show where the thrust spring is positioned on the carb assy. between both carbs. A picture or two is well worth the effort and reduces the cursing to a manageable level.

I am just doing a members new 450 bike and the last person who was in these carbs really did some creative work to say the least.