Smoothbore identification

I may be wrong on this but I seem to remember I saw a picture of some stock carbs that look alot like 29 smoothbores. Is that right? If so, how can you tell whether you have real smoothbores or a set of the look-a-likes? Is there a part number, casting mark, or another identifiable feature to be sure of what you have?

The float bowls have a caped opening on the bottom of the bowls so you can change main jets without removing the carbs and most of all when the slides are at full open there isn't a hole in the top of the carb body for the slides just a circle cut that the slides go through giving them a "smooth bore" at wide open.
Mark

The carbs I seen had the cap on the bottom of the float bowl but weren't 29's. As far as inside the carb, I couldn't tell. The reason I'm asking is that I bought a parts bike and it looks like it might have either this stock type carb or it has smoothbores on it. I could be so lucky! LOL It's a piece of junk for the most part but it has possiblities, especially if these carbs are the 29's.

Smoothbore has a jet block over which the throttle side moves up and down.

Viewing from underneath with float bowl removed, there is a small phillips head screw holding the jet block in place.

MEMO: Wiredgeorge cautions against removing the jet block as it invariably damages the delicate thin no-longer-available-virtually-impossible-to-duplicate gasket between the jet block and the carb body.

My 29's are as pictured on Z1E site, single large drain screw on bottom of float bowl, only a single fuel line attaching to a single fuel pipe joint located between the two inside carbs, and no accelerator pump.

Am having difficulty posting an exploded view of the VM29 smoothbore.

These links supposedly go directly to the exploded view.

click on thumbnail

click on see full size image

the view

Post edited by: Patton, at: 2007/08/26 09:33

If image is too small, try clicking on it which may show a button to click to expand the size.

Post edited by: Patton, at: 2007/08/26 09:38

Part numbers:

See above posts for help seeing the exploded view diagram.



87 = Jet Block

88 = Gasket

13 = phillips head screw


Were you able to get the exploded view diagram okay?

www.z1enterprises.com/reference/z1-carb-guide.aspx

Forgot about the difference in fuel line. That should be a give away alone. Going to check them out today so see for sure. Appreciate the info.

the floatbowls are not always a good way to tell this bike has a set of 29s on it with tops and bottems off of 26s without the drains to make people think theyre 26s from back in the sneaky days.

29's are unmistakable......just like the 33's.

The 29's I used to have also had the idle speed screw pointing up.
BTW I checked with Sudco this May on the jet block gaskets. They assured me they had them both via email and over the phone. It may be worth checking again?