Mikuni BS34 carb Q:

got a set of BS34 mikunis im workin on...
they have rubber o-ring caps in the pilot jet holes...
I assume this is because the carbs use non bleed (solid) pilots...
can I use bleed type pilots and loose the caps?

they are a PITA ...

or will bleed type pilots not work? I know with the non bleeds, they grab air from a passage to the main jet...

Either pilots will work but you must use the caps regardless.

otakar wrote:

Either pilots will work but you must use the caps regardless.

ok..
good..
I need to order pilots... I'll try to get the solid pilots first..
I'm not sure what are in there.... cant read the #'s ...

it has 130 mains...
I have a feeling these are stock pilots...
2 of the caps were a ROYAL pain to get out...

bike runs ok... but takes a lot of choke till it gets warmed up...

1984 gpz1100 with kerker pipe and pods...
what should the jetting be? ballpark?

The stock pilot size is more than big enough I run the stock 37.5 pilot in my GPZ1150 with a Kerker k-series pipe, Pod filters and .420" lift cams. I was actually thinking going down to #35 pilots. Lot of guys go to #40 pilots but than the bike is sluggish in mid range and ALL of your fuel efficiency gos out the window. Raising the needle by one notch however would help quite a bit.

The pilots you require are the BS30/96 series which are available from Z1E for $2.75 each.

I would go to 135 mains if you are running pod filters. There is less vacuum threw the carbs therefore you need larger holes to allow more fuel. Some guys run 140 or as large as 150 mains but I find that even with my cams and the radically ported head and large valves my 137.5 mains are a touch on the side of rich. The biggest shortcoming of those carbs are the needles. I have custom needles made and it makes all the difference in the world.

The BS34s you bought came from what bike? These carbs also came on the 700/750 bikes and require quite a bit of mods to work on the 1000 and up bikes. If they came from a 1100 or a 1000 police bike they should only require some re-jetting and needles.

I bought the bike with these carbs...
bike needed a head gasket..

got that done and now its running...
havent rode it a lot yet.... just figured I would go through the carbs... since I felt it could run better...
good news on the pilots... thanks.
needles are on the 4th clip from the bottom..

maybe I will try bigger mains...
I have yet to give it a good test ride after the head gasket...
maybe this weekend...

What is the needle #, and the needle jet #?

otakar wrote:

What is the needle #, and the needle jet #?

I didn't see any #'s on the needle...

and I didn't pull the needle jets out..

I took the bike for a test ride today...
accelerates and runs good. very good.. I was very surprised at the midrange-top power of this bike... it really turns on when the rpms get up towards the top...

I forgot to look down at the tach...

the only problem I have right now is an air leak somewhere... It has a hard time idling down... must be an air leak at the boots or vaccuum plugs/caps... gonna mess with it tommorow..

I'm not crazy about the mikunis... probably because I'm used to working on keihins...

but I think the jetting is pretty good... just gotta get this airleak sorted..