new carbs, installation questions

[jonko]

Hi all,

I just bought some new carbs for my cbr on ebay. Is there anything special I need to do when I install it? I know I probably have to sync the carbs, but anything else I need to worry about? Do I have to adjust the needles and jets?

Thanks.

 

[the grinch]

You should probably clean them. It would be a good idea to find out the stock jet sizes and settings from your service manual, and set them to stock if they aren't already.

 

[auntiebling]

if they were shipped to you, and weren't wrapped in a separate plastic bag to keep packing material out, murphy's laws state you now have a little tiny spec of packing material wedged in some obscure passage deep in the belly of your carbs. cleaning them is a good idea.

why did you need new carbs?

 

[afm199]

Yes. Pray they are better than what was on the bike.

Pull the float bowls and see if they are clean or gunked up. Check the bowl gaskets to see if they are good. They might work.

 

[ST Guy]

I would make absolutely no assumptions regarding their condition or state of tune. I would never install them without first a nearly complete disassembly to clean jets and passages and float bowls, set the float height, note the jets installed, check the condition of the diaphrams, etc. Then, before they go on, I'd replace the rubber boots or insulators as Honda calls them. Finally, they'll require a proper sync and adjustment of the idle mix screw. And then I wouldn't trust them until I'd had a dyno run to confirm the fuel/air mix is correct. You don't want to fry your motor just because the carbs are set up weird or not working properly.

Make no assumptions.

 

[Marlowe]

What they said....

The best use of eBayed parts like carbs, brake stuff (MC, calipers, etc.) is as a source of rebuilding stock that isn't on the bike.

Order up a set of carb rebuild kits...then tear down and inspect these. If they look great, just clean them, and put them back together... then do the swap, tear down your existing carbs, and use the rebuild kits on those. If the new ones don't look so hot, fully clean and rebuild them, then install on the bike.

 

[Ironbutt]

Hi all,

I just bought some new carbs for my cbr on ebay. Is there anything special I need to do when I install it? I know I probably have to sync the carbs, but anything else I need to worry about? Do I have to adjust the needles and jets?

Thanks.

You can get pretty close bench syncing them.. Otherwise the engine may not start.. if this were my bike i'd tune it up to eliminate any problems that may cause it to not start.

So.. why are you replacing the carbs?