How to tell if a carb has been upgraded?

[brecchi]

Forgive my ignorance, but once I have them apart is there an easy way to spot any rejetting upgrades?   I got a Factory Pro kit at a great price a while back and my plan is to clean and rebuild the carbs if needed, and perhaps to add the jet kit.  The bike will have Yoshi slip-ons I purchased, and it came with a K and N filter.  The airbox is intact, but there are 2 large factory holes in the top, I'm not sure if there were snorkels there at one point.   In any case, I'm not so much looking for big power as much as a well running bike.

Just opened up the float bowls and everything looks surprisingly clean inside.  The gaskets look a bit worn.  Still trying to figure out how to upload photos on here.

Thanks for any advice.  Howie - if you are out there, you've always had plenty to share!

-Ben

[ducpainter]

re: photos...

we don't allow direct uploads. You need to host your pics on a pic hosting site, and hot link to them.

There were once snorkels in the large holes.

Slip ons don't typically require jetting changes. If you start drilling holes in your airbox lid you'll definitely need to jet it.

How does it run now?

[Howie]

I can't find the OEM jet sizes on my computer, but as you disassemble write down your jet and needle numbers and other markings. Others will know.  I like running a Factory Pro needle jet with a Dynojet needle.  If your bike is not cold blooded chances are it is jetted. 

If it is and it is a Dynojet kit:

https://www.dynojet.com/amfile/file/download/file/577aae37999e545c46552ab14776009f/product/3853/

https://www.dynojet.com/amfile/file/download/file/5634071ad6ee4138a4ab234a144c6023/product/3869/

Factory Pro and Dynojet numbers do not match.

[brecchi]

re: photos...

we don't allow direct uploads. You need to host your pics on a pic hosting site, and hot link to them.

There were once snorkels in the large holes.

Slip ons don't typically require jetting changes. If you start drilling holes in your airbox lid you'll definitely need to jet it.

How does it run now?

I'm actually not sure how it runs - I dropped a new battery in, cleaned out the tank as best I could with white vinegar, replaced the fuel filter and cleaned the K and N and fired it up.  It was leaking gas pretty badly, which is why I got the carbs out in the first place.  I discovered that the open vent lines from both carbs were pretty cracked (which I'm not sure has anything to do with the leak) and I also saw that there was no hose at all on the inner T fitting between the carbs.  I don't even see a hose hanging off anywhere, so perhaps it fell off at some point.

I'm more interested in a smooth running bike with just the slip ons and snorkels removed.  I still need to get more rust out of the tank.  Its in great shape on the outside but I noticed some rust already in the new fuel filter which I shook out.

[brecchi]

I can't find the OEM jet sizes on my computer, but as you disassemble write down your jet and needle numbers and other markings. Others will know.  I like running a Factory Pro needle jet with a Dynojet needle.  If your bike is not cold blooded chances are it is jetted.  

If it is and it is a Dynojet kit:

https://www.dynojet.com/amfile/file/download/file/577aae37999e545c46552ab14776009f/product/3853/

https://www.dynojet.com/amfile/file/download/file/5634071ad6ee4138a4ab234a144c6023/product/3869/

Factory Pro and Dynojet numbers do not match.

Thanks Howie, glad to see you are still on here.  I'll write down the jet and needle numbers and report back.  

I've also been looking for rebuild kits to replace the rubber but is seems a bit hard to find known quality parts.  If you know of a source, it would be pretty helpful.

[Howie]

http://www.nichecycle.com/ncs/categories/carburetor/mikuni-rebuild-kits/mikuni-bdst38-yamaha-ducati-rebuild-kit.html
https://www.dellortoshop.com/contents/en-us/d165_Mikuni_BDST_carburetor_parts.html

The only sources I know besides Ducati and Yamaha dealers.  I would go with the full kit with diaphragm since age has an effect and I like doing things once.

[brecchi]

Thanks for the links.  

First attempt at a couple of pics.  I'll get it apart later and look at the numbers.

[brecchi]

A few more pics - I can't seem to wiggle the jets held in by the rubber o-ring, is there a way to do this without damaging?

[brecchi]

Actually, I can't read what the jet says.  Can anybody help with that?

[Howie]

If it the needle jet you are taking about that doesn't normally get a different size, needle and needle position take care of that part.  They do wear though.  If it is brass use the one that comes in the FactoryPro kit.

[koko64]

The needle in the pic is a kit needle and not oem.
What colour are the needle jets (or emulsion tubes)?

I need a magnifying glass to read jet numbers nowadays

[ducpainter]

The needle in the pic is a kit needle and not oem.
What colour are the needle jets (or emulsion tubes)?

I need a magnifying glass to read jet numbers nowadays

It isn't a dynojet needle.

[Howie]

As the colors look in the photos it seems like the needle and jet are FactoryPro.

[koko64]

Yep. The needle has the more conservative FP taper I think.

[brecchi]

Thanks to everyone for the insight.  I ended up cleaning things with brake cleaner and compressed air.  It all looks pretty good in there and I'm just going to assume at this point that the carb has been upgraded, and nothing seems to be worn.  Since my original reason for getting into the carbs was to try to find the source of the fuel leak while running, I made sure to clean up the floats. 

Ive got them back together and I'm ready to reinstall.  I am a bit confused as to where all the drain hoses reattach - I've got 2 drain (or vent) hoses which need to be replaced (I've attached pictures below.)  Having trouble finding whatever size these are at the local parts store.  I believe there is a 3rd hose hanging off the bike which attached to one of the T fittings, and another T fitting of which I am not sure. 

I believe one of the hoses was incorrectly attached.  I've looked for a diagram online but can't find one.  Can someone confirm the fitting of the 2 hoses below?  Does one attach to the central T fitting and the other to the L shaped pipe off the side of the carb?