Topic: My 550 needs jets????

[hillbillychoppers]

After cleaning the rust out of the tank, cleaning the carbs agian, I need to change jets so. I'm looking for help, she has pod filters and 4into1, exhaust, right now she has the stock 100 main and 38 idle, any suggestions on what sizes to go to. Where can I get these fancy push in jets?? Thanks jeff

[M3JOC]

Hi
I`m also looking for that info, check out the post Carbs again.
Cheers,
bob

[mjrhondaguy]

Jeff,

What year 550?  I've rebuilt a couple of '78 550k's, and the when I did the first one I looked just about everywhere for the idle jets (the push-in ones) and couldn't find them anywhere.  Why do you think you need new idle jets?  They can be cleaned while still in the carb, which is definitely easier than trying to get them out, clean them and then reinstall.  I usually use a fine brass wire like a plumbers snake along with the liberal application of some carb cleaner

If you're sure that you want to get into removing/changin them, you could try davidsilverspares.com.  They might have them.

Matt
'90 pc800
'80 cb900c
'78 cb550k
'65 s65

[hillbillychoppers]

Hi
I`m also looking for that info, check out the post Carbs again.
Cheers,
bob

Bob I wish I'd read your post first, I thought your was probably about 750's, looks like we're in the same boat, the only difference I see is I'm running a baffle, and my bike is a 76. Stock size jets are all I've been able to find, so I'm thinking about drilling a old set, as soon as I can find numbered drill bits, I found this on another site, they say that a 105 jet is a #59 drill, a 110 is a #57 a 115 is a #56, and a 120 is a 3/64. I may be drilling a set out when I get back home Friday. Thanks for pointing me to your post.

Matt, my bike is a 76, she has screw in Idle jets, so I thought I might go a little bigger on them, I don't know if they'd need to be bigger or not, just thought I'd try changing them.

jeff

[MikeDeB]

Hi
I`m also looking for that info, check out the post Carbs again.
Cheers,
bob

Bob I wish I'd read your post first, I thought your was probably about 750's, looks like we're in the same boat, the only difference I see is I'm running a baffle, and my bike is a 76. Stock size jets are all I've been able to find, so I'm thinking about drilling a old set, as soon as I can find numbered drill bits, I found this on another site, they say that a 105 jet is a #59 drill, a 110 is a #57 a 115 is a #56, and a 120 is a 3/64. I may be drilling a set out when I get back home Friday. Thanks for pointing me to your post.

Matt, my bike is a 76, she has screw in Idle jets, so I thought I might go a little bigger on them, I don't know if they'd need to be bigger or not, just thought I'd try changing them.

jeff

Leave your idle jets stock for now and work with the mains.  When you get your bits, check them with a digital caliper.  Jet sizes correspond to metric dimensions.  I believe a 110 jet would be equivilent to .110mm.

[TwoTired]

  Jet sizes correspond to metric dimensions.  I believe a 110 jet would be equivilent to .110mm.

Oops misplaced decimal. 
A #110 Main would be 1.10mm.   Or, 1.1 millimeter = 0.0433071 inch, about a 57 number drill.
A #120 main would be 1.20mm, 1.2 millimeter = 0.0472441 inch,
a #56 drill is .046 inch, and a #55drill is .052 inch.
A 3/64 drill bit is .0469 inch.
You should be aware, though that twist drills make holes larger than they are depending on their cutting design.  A hole and bit exactly the same size would be an interference fit until it starts cutting enough material for twist or movement clearancing.

See:
http://www.onlineconversion.com/length_common.htm

It would probably be better to use jet reamers and guages rather than ordinary twist drills since the latter will leave jagged, out of round holes that will flow unpredictably at different fluid speeds.  But, it's your call.
http://www.cbperformance.com/catalog.asp?ProductID=525

Cheers,