Carb Questions

Roberd42 · Post by **Roberd42** » Tue Dec 02, 2014 4:33 am

I have two carbs in my box of parts on this basket case ca95 I'm trying to piece back together. One is a newer looking, clean carb with a "K" (Keyster?) on the side. But it has no bell for the air cleaner tube. The other is a keihin. It has two jets on the outside top, looks much older, and has the bell for the air cleaner hose. I tried to see if I could just retrofit the bell to the newer carb (I'm not sure about all those removable air jets) but it has a lip that would have to be ground off and I'm not sure that would work. I hate to bastardize a good carb as the lip would help hold a newer uni pod filter or something. Bottom line, which carb should I use performance wise and for ease of use?

VegeKev · Post by **VegeKev** » Tue Dec 02, 2014 12:01 pm

The one with the jets on the outside at the top is the correct one. The 'extra' jets are the power jets which supply extra fuel at 6000+ revs.
The CA95 and the CB92 ended up with the PW20HA3 carb, while the C92 got a PW18HOV and the C95 got a PW20HOV.
Kev.

Roberd42 · Post by **Roberd42** » Tue Dec 02, 2014 4:48 pm

Kev, what are the correct jet sizes for the two power jets, the pilot, and main? I'm not sure if these have been changed.

VegeKev · Post by **VegeKev** » Tue Dec 02, 2014 8:59 pm

For a standard CA95, the manual says;

Main jet #95
Slow jet #35
Power jet #130 (this is the one that sits behind the power air jet at top of carb)
Power air jet #130 (this one is on the outside-ish of carb)

There is a link in here somewhere for a copy of the manual.....BTL or Smithers may be able to point the way

Sam Green · Post by **Sam Green** » Wed Dec 03, 2014 4:32 am

Well done Kev, spot on.

Sam.

Roberd42 · Post by **Roberd42** » Wed Dec 03, 2014 5:45 am

Wow I feel stupid haha! I looked in my manual and poof there it is. Every other bike I have doesn't have jet sizes in the maintenance manual even. It's closely guarded juju by the manufacturer. This is a first. Thanks again!

Roberd42 · Post by **Roberd42** » Wed Dec 03, 2014 8:57 am

What is the right needle seat? I have a 1.7. Online I see 1.2, and typically stock platforms have a 1.5. My power jets were 180, 130, main 100, pilot 35. A bunch of silicone crap on the neck where the bell connects. It's definitely been fiddled with.

VegeKev · Post by **VegeKev** » Wed Dec 03, 2014 11:48 pm

Are you talking about the float needle or the throttle valve needle?.....i'm gathering the float needle cause I've never seen a number on the throttle needle seat.....either way its a great question......wish I had a great answer!

I haven't the foggiest

Kev.

Roberd42 · Post by **Roberd42** » Thu Dec 04, 2014 4:17 pm

The float valve seat is what I'm fishing for kev. The needle jet is listed in the manual but not the seat valve size. All genuine seats are usually stamped a size. My other keyster carb doesn't have stamps on the seat or any of the jets. I haven't looked at the needle yet. Maybe Sam knows

Sam Green · Post by **Sam Green** » Thu Dec 04, 2014 5:55 pm

The float valve seat is the devise that lets gas come into the float chamber when the float level drops, is this what you're talking about. It don't have a number as far as I know, I would guess they are all the same.
When you talk about having two carbs and one has a K on it, it is probably K for Keihin not Keyster. As far as I know, Keyster are just an aftermarket repair kit supplier.
Pictures of what you have would be helpful.

Sam Green · Post by **Sam Green** » Thu Dec 04, 2014 6:00 pm

The float valve seat is the devise that lets gas come into the float chamber when the float level drops, is this what you're talking about. It don't have a number as far as I know, I would guess they are all the same.
When you talk about having two carbs and one has a K on it, it is probably K for Keihin not Keyster. As far as I know, Keyster are just an aftermarket repair kit supplier. http://www.keyster.ca/
Pictures of what you have would be helpful.

Roberd42 · Post by **Roberd42** » Fri Dec 05, 2014 6:40 am

I'm talking about the float valve and seat. The valves are all the same but the seats have different size openings (in mm) typically 1.5, 2, 2.5, 3. From what I gather, you aim for the smallest size that doesn't starve the bowl at extended WOT with your jetting. If it's too small, it will cut out near top speed as the bowl goes dry. On my ski carbs you adjust needle seats and springs for pop off pressures. Of course these are a lot more simple than that. So I think the seat size is just determined by WOT fuel requirements. If it falls on its face after a bit at WOT, go up a seat size.

The "k" on the newer looking carb doesnt look like the keihin starred "k" and it doesn't say keihin like the other pw20. Maybe you can identify the manufacturer/model. None of the jets are marked in this one either. Here are pictures. I may have to post each separate as my iPhone does weird stuff on the multiple picture uploader.

Roberd42 · Post by **Roberd42** » Fri Dec 05, 2014 6:41 am

Needle seat

Roberd42 · Post by **Roberd42** » Fri Dec 05, 2014 6:42 am

K carb 2

Roberd42 · Post by **Roberd42** » Fri Dec 05, 2014 8:44 am

I did some research and posted this to facebooks vintage Japanese bike group. It's a Sheng Wey chinese carb. So, I will definitely be using the genuine keihin.