XS1B engine and BS34 carbs can they work together?

[Metal]

Hi guys. So I'm getting to the tune and engine work part of my build and the following combination is what I'm running.
XS1B engine with open headers finishing behind the foot pegs.
BS34 carbs, new diaphrams with pod filters
New manual points
New coils 4ohms
12v .08amph battery
PMA


I'm getting around to making all this gear work together.
I have some questions.
1. Can I run BS34 carbs with a XS1B engine?
2. Concidering my set up what needles and jets should I run or what would be a good base line to start with?
3. What's the best way to transfer over the timing marks to the PMA? I've looked at Hughes how to but just sighting TDC through The spark plug hole seems not very precise.

 

[XSLeo]

Yes, those carbs will work fine. On the BS34 carbs there isn't much of a zselection of needles and needle jets to be had. The stock ones work fine. The pilots and mains are another story.
I would start one up on the pilots and two up on the mains, Test and adjust from there.
Your short open headers will make tuning harder. The pods you use will make a big difference in tuning the carbs. The K&N stlye tapered pleated fitler with an oval or cone shape are the hardest to tune to. The longer straight ones not much better. A long straight foam air filter works best.
The pleated filters cause air flow turbulance through the carbs that disrupts the vacumm signal the carb need to lift the slide.
www.amckayltd.com/carbguide.pdf has a section on carb tuing.
There are several ways to find TDC. Looking through the spark plug hole gets you close. With the piston down a bit slide a drinking straw in the plug hole so it sets on top of the piston. Now as you rotate the enguine watch the straw. It will move donw as the piston comes up. TDC is when the straw is at it lowest.
A piston stop and degree wheel is more precise. Put the deghree wheel on the crank. Put the piston stop in the plug hole Rotate engine til the piston hits the stop. Put a wire on the engine some where near the degree wheel Bend it so it points at the degrre wheel. Like at zero degrees. Turn the engine the other way till it hits the piston stop Note where the needle sets on the degree wheel. Say 73 degrees. Half way between the first stop and second stop will be TDC. Remove the piston stop. Turn the engine to half way between the to degrees, mark the rotor to aline with the TDC on the sticker provided in Hugh's kit.
Leo

 

[Metal]

Thank you for the main and pilot advice. I am going to get #140 mains and #45 pilot both from mikesxs.
If anyone has a difference in opinion please let me know. Thanks

 

[gggGary]

IMHO go with genuine mikuni parts, the knock off stuff is such a crap shoot, if the jets don't flow fuel as marked you are going to be SO lost in trying to get it dialed in......

I tend to add a washer under the pill on the needle jet to raise it a smidge this tends to remove the just off idle flat spot.
Heads up; I learned "the hard way" that there is room for only one washer, a second washer binds the jet retaining spring coils and the needle will bind in it's jet and stop the slide from dropping all the way. Yeah that took some head scratching to figure out.

 

[Metal]

Where could I get OEM then?

 

[jriehl08]

http://jetsrus.com/a_jets_by_carburetor_type/a_jet_kits_mikuni_selection.htm

I have ordered oem jets from them for different carbs I have worked on with great results.

 

[Metal]

Thanks. I'm looking at bs 30/96 right?

 

[jriehl08]

I believe so but Im sure someone else will chime in for sure

 

[5twins]

BS30/96 pilots and N100/604 large round mains .....

 

[gggGary]

I order some jets from ebay vendor nichesupply
I have also ordered from Rocky Mountain ATV/MC