carb cleaning my 450L

[Erich Z]

Well, I've got the carbs off the bike, and I think I have one completely disassembled. The carbs on my 450 differed quite a bit from the instructions online - didn't see a needle jet, for example! Maybe I missed it somehow...

Anyway, I'm looking forward and foreseeing a couple problems you may be able to help me with. First, the carbs were a total bear to get out - the air box only moves back maybe a half inch and doesn't allow much movement. Any tips?

And here's the biggie. What is the easiest way to balance the carbs? Do I really need a manometer, or is there an alternate method that works. Does anyone in mid-Michigan have a manometr I could borrow, or alternatively, where is the cheapest place for one? I only have the 2 carbs...

[Steve]

When you remove the main jet, there is a long brass tube in the tube on the other side of the jet. That tube is full of holes on the sides, and a calibrated hole on the top. That is the needle jet. The jet needle is attached to the slide on the bottom of the diaphragm, and slides down into the needle jet, metering fuel flow in mid-throttle applications.

The easiest way to balance the carbs is with a manometer. Yeah, you only have two carbs, but most of the kits out there are for four. Maybe I can send you the two extra ones from my set. I have a six-column set of mercury sticks.

.

[Nessism]

Twins can be balanced by pulling off one plug and seeing what happens to the idle. Not the best way but better than nothing.

[Erich Z]

Nessism, can you expand on that?

Thanks guys...

[Nessism]

Set the idle up to 2000 or so and pull off one spark plug cap. The idle speed will drop down to 1000 or so. Put the plug cap back on and start the engine. Now pull the other side plug cap. If the rpm drop is not the same, tweak the carb balance using the adjustment screw.

This is not the best method but it's better than nothing.

[Erich Z]

Found the needle jet...



Question is, how do I get it out?

[Erich Z]

Question is, how do I get it out?

Anybody? I tried vise-grips and wiggling it out, but I don't want to damage it. Any other suggestions, or just yank the sucker?

[Erich Z]

Well, I guess I'll just leave it as is and reassemble. Is dipping the float bowls all that necessary anyway?

Please let me know if I'm making a big mistake.

[Nessism]

Do you have a heat gun? Heating the aluminum around the jet will loosen the varnish and make the aluminum expand so hopefully the jet will come out.

[Erich Z]

Ha, got a hair dryer...

I can probably borrow a heat gun though.