Which jets should I use?

L

LocoKen

XS650 Enthusiast
Messages
34
Reaction score
0
Points
6
Location
Seattle, Wa
Mike's is out of the #42.5 Pilot Jet BS30/96 type which is the stock for my BS34's. What would you guys recommend in place of them and/or would you also replace other things as well if an alternate is used? Thanks.
 
Don't assume that Mike's XS is the only place to buy parts for your bike. There's about 25 million bikes in the US. Some of them use the same parts.:thumbsup:
 
I tell people time and again - you don't want the jets from Mike's anyway, they're knock-offs. Get genuine Mikuni jets, they cost pretty much the same. Why buy cheapo copies???? A jet is a precision part and Mike's isn't noted for quality control.
 
Found one place online called motorcyclecarbs.com that has what I need. Anyone heard of them? Or do you have any other suggestions on places you've bought carb parts from? Thanks for the help so far, everyone. Greatly appreciated!
 
grepper said:
Mike at 650 Central can help you out. You can also go through Sudco
Click to expand...
Couldn't find any BS34 parts on the Sudco website. 650 Central has some but I'm wondering if they are knockoffs or OEM. Hmmmm......

Thanks for the heads up, grepper. I will be calling Mike tomorrow hopefully if he is available to answer questions.
 
You're not buying "BS34" jets, you're buying Mikuni BS30/96 type pilot jets. They're used in lots of different bikes. I get mine sometimes at several of the local shops around me (if they have the size I'm looking for). Shops out in the country that cater to dirt bikes, ATVs, and snowmobiles usually have a good selection of jets on hand.

Same thing goes for your main jets. Your BS34s use the large round style of Mikuni main, pretty much the most common main jet on the planet.
 
5twins said:
You're not buying "BS34" jets, you're buying Mikuni BS30/96 type pilot jets. They're used in lots of different bikes. I get mine sometimes at several of the local shops around me (if they have the size I'm looking for). Shops out in the country that cater to dirt bikes, ATVs, and snowmobiles usually have a good selection of jets on hand.

Same thing goes for your main jets. Your BS34s use the large round style of Mikuni main, pretty much the most common main jet on the planet.
Click to expand...
Thanks 5twins, JR Roxx. I will do just that. Thanks for the tips. Didn't realize that they were that popular in many carbs. Again, thanks!
 
niche cycle , an ebay seller has gennie mikunis. seems fair pice. made multiple purchases with them, no problems. I usually get the order a day earlier than what the tracking says.
 
Just to echo what several informed are saying....you're either getting Mikuni jets for your BS 34 or BS 38 CV carburetors or you're not and in my opinion it's important! First thing to learn is what the specified designation should be, what you have or find to be in your carburetor and then what you want to get and have. Sudco is the principal distributing source of Mikuni carburetors and parts in North America.

I've found a number of good sources for same like 650 Central, Dennis Kirk, JC Whitney, Yamaha dealers, Powerplus, Z-1 Enterprises etc. to name but a few. Sudco has a lot of good info. at their site...http://www.sudco.com/ But you are the one responsible for knowing, specifying and ordering the correct jet and size. Sadly many don't know the details of what they have or want. So.... knock off's abound....so do horror stories. I have come to the opinion, the hard way, that 5twins advice of getting genuine Mikuni for Mikuni carbs is the way to go.

Here'a a good site with information supplied that can help you figure it out (assuming that you know your carburetor Mikuni CV carburetor BS Series (38 or 34) and it's OEM jets supplied by both type and size. What you have....what you want....and why. Copish?

http://www.pjmotorsports.com/mikuni-jets.html#pilot/slow jets

Really good information displays here and sourcing too though a bit more pricey than can be found other places. You will have some homework to do re both the correct designation of what you have and what you want. PJ's charts are most helpful in this regard. Yes, you'll be back into the oft referenced carb guide of 5twins an Grizld1 http://www.amckayltd.com/carbguide.pdf to learn of both what you have and want. Blue
 
Last edited:
Thanks Blue for the info! You guys have been a great help and I sincerely appreciate it. I went down for the third time to the local Yamaha dealership and got some OEM pilots, finally. They've been out of parts for my carbs for weeks now and had some for every other size. Gonna get it up and running again today and will hopefully have some good news for you all. Thanks!
bluebikerblan said:
Just to echo what several informed are saying....you're either getting Mikuni jets for your BS 34 or BS 38 CV carburetors or you're not and in my opinion it's important! First thing to learn is what the specified designation should be, what you have or find to be in your carburetor and then what you want to get and have.

I've found a number of good sources for same like 650 Central, Dennis Kirk, JC Whitney, Yamaha dealers, Powerplus, Z-1 Enterprises etc. But you are the one responsible for knowing, specifying and ordering the correct jet and size. Sadly many don't know the details of what they have or want. So....those selling knock off's abound.

Here'a a good site with information supplied that can help you figure it out (assuming that you know your carburetor Mikuni CV carburetor BS 38 or 34 and OEM jets supplied by both type and size.

http://www.pjmotorsports.com/mikuni-jets.html#pilot/slow jets

Really good information displays and sourcing though a bit more pricey than can be found other places. You will have some homework to do re both the correct designation of what you have and what you want. PJ's charts are most helpful in this regard. Yes, you'll be back into the oft referenced carb guide of 5twins an Grizld1 http://www.amckayltd.com/carbguide.pdf to learn of both what you have and want. Blue
Click to expand...
 
Another good source if you know what you are after is jetsrus.com. Just make sure you know exactly what you are looking for.
 
I have an 81 xs650 special heritage and I've removed the original air filter box and want to use pod filters instead. I was told I need to increase the jet size or it will run lean. Is that true and any sugestions on size and type? Also anything I might need to know for this mod maybe regarding the breather hose or whatever else! Thanks!
 
Welcome to the site. Last guy I met who went by that handle went about 6' 4'' 300+. Tough day on the gridiron
Do you know your carbs? Are they Mikuni CV's BS 34's as supplied OEM to your make and model? What jets are in them know? What sizes ? etc. etc. Assuming that no changes have been made to OEM carburetion, intake or exhaust since 1981 is well.... quite a stretch.

None of us have that information? Assuming all, I guess it can be said that yes it is often the case that one wants to go up in size of main and pilot jets a bit when stock air filters and boxes are taken out. But; not necessarily? What pods are you going to use? How's the bike running now? Plugs?

There's a whole lot of very good info. from which to learn re these subjects and much more in the "tech section". Might want to start with the Carb Guide listed above. Whatever, it seems to me that you've got a lot of info.to gather

Best, Blue
 

Similar threads

modieselguy
1974 TX650a Carburetor Question
Replies
9
Views
318
5twins
5twins
J
XS500 carburetor problem.
2
Replies
21
Views
1K
arcticXS
A
750triples
XS 750: A Tale of Carb Rejetting Woes
Replies
1
Views
465
5twins
5twins
lumbee
AVMCP (another VM carb post)
Replies
11
Views
298
Bruno_c
B
zrx1100
Filter/intake flow testing (with results)
Replies
9
Views
554
Kevin Werner
Kevin Werner
Back
Top