jetting question (got 145 mains...)

[ERM83]

What type of emulsion tubes should I have?! I've looked this up EXTENSIVELY, and can only find "model numbers". I've been working on this thing ALL night, to the point where the carbs are the only thing I CAN work on, until I get gaskets to put it back together. Am I that inept that I can't figure this out?! I'm irate right now...maybe just tired, but my OCD won't let me sleep until I figure this out. the mains are the (definitely genuine mikuni) 145's, and the large head type. the searching is pissing me off to no end...I feel like a friggin' moron.

[ERM83]

threads are bigger on the 145's...forgot to mention that. did they send me the wrong ones??

[bikerphil]

The 79 Special uses 2 different emulsion tubes, the ones with the least holes (don't know the P/N) go in carbs 2+3 and the ones with more holes (266 X-2, P/N 2H7-14941-02-00) go in 1 and 4.

More info...

http://www.xs11.com/forum/showthread.php?t=39799&highlight=needle+jet

[BA80]

Best I can do for you. As was stated, the 79 used 2 different needle jets (emulsion tubes). The 2 center tubes had fewer air bleed holes so the 2 center cylinders would run slightly richer for cooling purposes. Yamaha decided that wasn't necessary I guess because the later models didn't have that.

[TopCatGr58]

threads are bigger on the 145's...forgot to mention that. did they send me the wrong ones??

If the jets won't screw into the end of the Jet NEEDLE/Emulsion tube, then yes, they sent you the wrong jets. The thread size doesn't change with the jet size. Not sure who THEY are where you got the jets from, but sounds like you need to contact them to see what's what!?

T.C.

[motoman]

Have a good idea where that chart came from Greg. The issue with that chart is: the 80-81 Specials used 110 main jets across al four carbs. Reason being, those yr. Specials had different configured metering rods than the the Standard, and different letering/numbering also.
The 80-81 Specials metering rods are tad shorter and have a quicker taper along with they go to a point. The 80-81 Standard metering rods have a more gradual taper and go out to a more blunter end.
80-81 carbs, other than that ARE the same. The Standard was considered the LD bike and the Special was considered the quick 'bar-hopper'. Use of both styles on my Venturer have proved that out to be true.

[Schming]

The 80-81 Specials metering rods are tad shorter and have a quicker taper along with they go to a point. The 80-81 Standard metering rods have a more gradual taper and go out to a more blunter end.

I believe you have the length factor correct but the Standard's Jet needles are sharply pointed and Special's are blunt.

[ERM83]

yep...

wrong ones. no worries...I can't really make any progress right now, anyway...I've done all I can, and was just going to build the carbs JUST to get it done in the meantime while saving money for a gasket set / torque wrench / new head bolts. I'll get the correct jets in the next couple of weeks, get everything else needed, and hit the garage HARD. Everything else is pretty much cleaned up, and ready to go. Put my "superbike" bars on...feels SO MUCH BETTER already! can't wait to take a ride with them on. I've got my pod-mod (THANKS, T.C.!) ready to roll as well!