Are these right?

[Eastcoaster]

Cleaning a set of carbs off 1979SF Here is what I found
Could this be correct?
Bike has a 4 to 1 exhaust that's the only mod

[TomB]

I don't know sorry, but have just assembled my carbs and never noticed, got me wondering now. They all looked the same in my carbs but could be model specific? mine are 2H9 Standard

[mack]

needle jets

Yes there was two different tubes used. The principal was that the inner two cylinders don't get the same air flow as the outers so will run hotter. To compensate more gas is pushed to 2&3 so they can run a bit richer. If I'm not mistaken, the more holes the more gas so you will want to change yours around. The jetting sounds correct for your exhaust if your not running pods on it.

[natemoen]

Yes there was two different tubes used. The principal was that the inner two cylinders don't get the same air flow as the outers so will run hotter. To compensate more gas is pushed to 2&3 so they can run a bit richer. If I'm not mistaken, the more holes the more gas so you will want to change yours around. The jetting sounds correct for your exhaust if your not running pods on it.

The holes are air bleed holes. The more holes the more air is introduced to the mix. Fewer holes go in the middle, more holes go on the outside.

[bikerphil]

The holes are air bleed holes. The more holes the more air is introduced to the mix. Fewer holes go in the middle, more holes go on the outside.

This is correct.

[mack]

Sorry

Good god, the only thing worse than not knowing, is getting bad advice.
Been a while since I've worked on the 78/79 carbs. Nice catch Nate. Seems this was a discussed at length a few years ago when someone produced a chart that was in error as well.
Eastcoaster listen to the pro's not me! Their right all the time. As for me, I will make sure I have finished my morning coffee and am thinking straight before I open my mouth.

[natemoen]

Eastcoaster listen to the pro's not me! Their right all the time.

More bad advice

I am wrong very often!

[crazy steve]

'Bad' advice is rare here.... Now, 'incorrect' advice can be a bit more common...

[Winterhawk]

That is excellent info on the Needle Jets. I had no idea. This site with the members input is a God Send. I've used advice from here many times over the years even with Bob Jones.

Thanks

[TomB]

Eastcoaster, could you tell me what numbers/letters they have stamped on them?

[mack]

Numbers

Had two coffees so I'm ok now. Tom the numbers stamped are: X2 for size on both and 1 + 4 should have the four holes all around are series 266, The ones for 2 & 3 have the 2 and 4 hole combination and are series 301.

[Eastcoaster]

numbers

Here is the best I can tell

1 and 4 x-2 266

2 and 3 X-2 301

All cleaned up Do you think I am good to go with these?

[Eastcoaster]

YUP Talk about bad info

Mack you have them right!!!

Do I dare tell you how many times I read them upside down and was ready to post!

Thanks everyone
Coaster

[TomB]

Thanks fella's

I have a set of Special carbs to do next, so handy to know, I've never done Special carbs before.

I've checked my 2H9 carbs have all X-2 266.

[TomB]

I've been using this site for some good info.....

Jetsrus.com