12R-14105-00 is the superseded # of 4G0-14923-00 from the 1980 XJ400 Japanese model. same # different Prefix as the Japanee B34 pilot screw 3L1-14923-00
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100% Canadian 1980 BS34 Jetting Specs please?
- Thread starter Vincenthdfan
- Start date
If your going off the 4E3 Japanese set up here is the 2nd page showing the size for #46
It would appear that does say its a 130 air jet....interesting.
How would ya'all interpret line #24?
I think its stating that 130 main is standard, but I'm not certain if that's just aligning with the item to the right (132.5)? Its kind of confusing.
Even more odd, the pilot aligning with the US lean 42.5.
I think @jpdevol is onto something when he states the Canadian/Euro needle and needle jet combo makes it richer throughout the range.
Yes, it does. And the 130 air jet makes the idle circuit a bit richer as well. If you study this chart I made up, you'll see that smaller mains are routinely paired with larger (richer) needle jets. That would explain the 130 main jets .....
Pilot jets on the other hand, don't change that much. It is nice that the BS34s have that removable idle circuit air jet. Many don't utilize this valuable fine tuning aid. It doesn't have as big an effect as changing the pilot jet size so with it, you can achieve richness levels in between pilot jet sizes.
Pilot jets on the other hand, don't change that much. It is nice that the BS34s have that removable idle circuit air jet. Many don't utilize this valuable fine tuning aid. It doesn't have as big an effect as changing the pilot jet size so with it, you can achieve richness levels in between pilot jet sizes.
It'll depend on the intake and exhaust you're running on the build; but, if ya start with stock "Canadian" jets, a 42.5-45 pilot and the fuel screw adjustment will likely be enough to geterdone. The main; my guess would be a 130 to start with a size either direction on standby. Then you'll also have the adjustable needle to play with if needed (doubtful).
I'm goofy, but I like to set my pilot circuit a bit rich for drivability and to where 15sec max of choke is all that's needed on cold start
I'm goofy, but I like to set my pilot circuit a bit rich for drivability and to where 15sec max of choke is all that's needed on cold start
I still have all stock intake and exhaust on both bikes.
I just want to get a little quicker transition to the middle of the acceleration band instead of the lean hesitation down low that they both have right now.
That and that godawful excessively long half-choke warm up/ride off necessary to get under way at the beginning of the day.
I probably will alter the exhaust and maybe intake filtration on 1980 #1 eventually, just for a comparison to stock on 1980 #2....see what sort of difference it makes, seat of the pants. I wont do anything I cant reverse back to stock however.
Have you tried the little 3mm washer under the needle? Did that to my SG and it definitely helped eliminate the off idle stumble.
+1 on JP's richer pilot circuit. You don't really spend much time down there anyway, but it really cuts down on warmup time.
No I havent, but I did order two sets of Canadian needles and Canadian needle jets.
Also ordered a slew of genuine Mikuni jets up and down the range (to include 130 air jets) from Jet R Us.
Sure adds up quick $$ when you have to order everything times "two" bikes because I'm too impatient to experiment with just one at a time.
.....he'll be runnin' out soon
FWIW, both of my stock Specials run like they’re fuel injected, although the smaller air pilot jet makes the SK harder to start. Theoretically, both bikes are the same, but they aren’t. My jetting for each is in an earlier post. At that, both bikes are a quick warm-up.
There are different ways to do it and I don’t think these experts are doing it wrong. I followed @5twins and I think I’m close to as good as it gets. Fatter pilot jet gave me a stumble at the changeover.
There are different ways to do it and I don’t think these experts are doing it wrong. I followed @5twins and I think I’m close to as good as it gets. Fatter pilot jet gave me a stumble at the changeover.
Yep, you can bet I bookmarked your post/specs.
Well this is pretty cool....
A few months ago my phone died. I don't get it... it was only 6 yrs old.
Anyway, bought a Pixel 7 Pro. The camera in this thing is unbelievable. Here's the macro setting.
I might just throw my magnifier in the trash.
Main Jet...
Pilot jet...
A few months ago my phone died. I don't get it... it was only 6 yrs old.
Anyway, bought a Pixel 7 Pro. The camera in this thing is unbelievable. Here's the macro setting.
I might just throw my magnifier in the trash.
Main Jet...
Pilot jet...
You know, looking at your settings further, it occurs to me that it just reinforces @5twins point about going richer on top and on bottom (either through pilot jet or air jet), has the same effect as changing to the Canadian needle & needle jet (bleed over/overlap).
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Amazing....who needs bifocals and a magnifying lens anymore?!! (You really could use a manicure by the way!)Well this is pretty cool....
A few months ago my phone died. I don't get it... it was only 6 yrs old.
Anyway, bought a Pixel 7 Pro. The camera in this thing is unbelievable. Here's the macro setting.
I might just throw my magnifier in the trash.
Main Jet...
View attachment 240809
Pilot jet...
View attachment 240810
