[Apriliarider]

I got the idea to do this from Saabnut and his "big bad rebuild" thread. Having a separate comments thread for people to ask questions and/or comment on what has been posted to the PSS thread satisfies two things.



My want to keep the build thread comment free until the end, as well as allow viewers/readers/members to chime in when they have a question or comment. I will check back a few times a week to answer questions.



So, for the future, if you have a specific question about something, feel free to ask it here. If you can copy and paste the passage from the thread into a quote, that could be helpful as well. That way we both know what your question is specifically related to.



My approach has been to break the project down into 3 phases. Teardown is phase 1 and is mostly complete now. Repairs is phase 2 and is where I currently am. Phase 3 will be the build which will terminate once the body work is painted and installed.



As I've previously stated, I have a plan for this build. I won't reveal what the end product will look like until the end. All other questions are welcomed.


Fire when ready.....sean

 

[Saabnut]

As I've previously stated, I have a plan for this build. I won't reveal what the end product will look like until the end. All other questions are welcomed.

Fire when ready.....sean

Heh, I know the direction your project is going, but I'll keep my mouth shut and let it be a surprise for everyone else. ;D

 

[Apriliarider]

Heh, I know the direction your project is going, but I'll keep my mouth shut and let it be a surprise for everyone else. ;D

Thanks man...much appreciated!...sean

 

[Apriliarider]

From ducatiman in the PSS thread:

If I may be allowed a correction.....the large, upper jet is in fact the starter circuit jet #70 , the smaller jet below it in the 2nd pic is, in fact, the main jet. It simply presses in, is "o-ringed" and slotted, held in placed by the metal tang pictured.

Any minor imperfection to the starter jet is just that...minor.

My apologies for not addressing your comment sooner, but as we already spoke about it....


For those not involved, yes, we actually spoke. You know, the old fashioned way, on a phone? Really.



I was standing outside Factory Pro in San Rafael when ducatiman and I talked briefly. He informed me then of my incorrect identification of the starter jet....right after the guys at Factory Pro told me the same.



My thanks to you for sharing your expertise with both me and the forum. I truly thought I was looking at the main jet as that is how the Mikuni BSTs on my old Gixxer are set up.



When ducatiman and I talked, he told me where to find the main jet, like in his post to the PSS thread. I duly found said main jet to report the size back.



Needless to say, I'd already bought a kit from Factory Pro containing the same jet. Funnily enough, it is smaller (leaner) than the OEM jet. The Factory Pro website also recommends the smaller than OEM jet for tuning.



Not that I needed any confirmation of what ducatiman had already asked me get. I was pretty much there on a mission to track down all that he asked me to get for the rebuild on the PSS carbs. The one thing I really went to Factory Pro for, they didn't have.



I'll have a post up in the PSS thread regarding that in the near future as I've had to order them from an online parts dealer. Hopefully, they will require no further work to get them where they need to be once they arrive here.....sean

 

[ducatiman]

Just acquired another set of Duc/Mikuni for salvage parts, bowls should clean up nice. They are there if need be.

 

[ducatiman]

These Ducati/Mikuni carbs belong to @Apriliarider. I've been assigned to "do 'em up".
Ok, they are nasty, no denying that, but nothing major.

I'm just starting prelim, 1st go 'round stuff. Note contrast in bodies (but not near completed as yet)

I'll spare y'all pics of internal nasty areas, unless you want them.

Split, disassembled with minimum fanfare, save a frozen pilot screw, which I safely removed (big sigh of relief there)

 

[Apriliarider]

I'll spare y'all pics of internal nasty areas, unless you want them.

Oh we want 'em alright! :grin2: The more gruesome the better....just like the evening news:grin2:LoL....thanks for the update.....sean

 

[ducatiman]

I'll start some procedures on small components today, as the 3rd pic indicates there's a huge quantity of stuff involved, whether by hand or machine all will be micro cleaned, as close to "as new" condition as I can achieve.

These are the jet blocks....they hold start, pilot and main jets. Hey, there's gaskets under all that white powder! And more powder UNDER the gaskets, too. The jet block/gasket/carb body seal *must* be concise here, no leaky.

I'll surmise this bike lived outdoors at some point.

 

[Apriliarider]

I'll surmise this bike lived outdoors at some point.

I've concluded the same. Also concluded the bike lived in the Monterey area for most of its life. Salt air will cause all manner of corrosion, like the stuff I pictured on the wheel in the main PSS thread.



However, I concluded it must have been under a carport or other source of cover because the corrosion just isn't consistent.



Then again, with as much oil and suspension fluid that was leaking it may have prevented some amount of corrosion from taking hold. Really. It was that bad.


I'm just glad to see some progress....it's disheartening when all you see is the repair list getting longer rather than shorter.....sean

 

[ducatiman]

as far as carbs are concerned, i think our pm's tonight will resolve the last of the minor issues i've encountered. detail, detail, detail, decisions.

 

[Apriliarider]

as far as carbs are concerned, i think our pm's tonight will resolve the last of the minor issues i've encountered. detail, detail, detail, decisions.

I got home from work and found all the PMs.....Answered them all....I think. Lemme know if I missed anything :smile2:....sean

 

[ducatiman]

One more from this evening. A long day for me with great progress. Cleaning phase almost complete, just bodies and slides left. Assembly phase next.

Some sample and before/after pics. I don't want to hog the thread here, though.

 

[Apriliarider]

Some sample and before/after pics. I don't want to hog the thread here, though.

Oh by all means, hog away! :grin2:There isn't much else going on with the PSS at the moment so your progress is the focal point.



Thanks for the pics.....and yes, the bowls look fantastic

...nearly new. Compared to what they looked like when I opened them up, I'm ecstatic. Looking forward to seeing the rest.......sean

 

[ducatiman]

Smart Mikuni designed full access to transition ports for inspection/cleaning ...these carbs, though tricky if you intend to "go all the way", have been designed with service in mind.

the 3 tiny holes you see in the pic are the transition ports, above 3 larger holes the all important circuits....but there is more, much more

 

[ducatiman]

Today, I'm performing some bench experimentation and trial to offer a solution to a long time, controversial, Ducati/Mikuni carb issue, premature, brass needle jet wear resulting in uncontrollable, rich running. Nickle plated, Factory Pro needle jets have been the fix to date but are NLA. I believe I've found both the root problem, and a reasonable solution.....adding a tiny spacer..... pending actual on-bike testing. All indications point to success.

The cut slide is NOT Seans...sacrificed from my spares in order to facilitate some visual aid for the trial.

Sean will understand the photo's, discerning between with/without my spacer. We can discuss further if necessary.

1st pic is standard Mikuni setup, without spacer, needle preloaded due to the "step" 2nd with my spacer, the needle straight as an arrow 3rd the sacrificed slide cut-off 4th with spacer and the "found" carb washer, which seats perfectly flat, assuring a true, stable, horizontal needle mount point.

long day, i'm beat, signing off. NY Yankees vs Boston division playoffs on.

 

[ducatiman]

I physically correlated the needle preload/tilt to the *exact area* of wear/ovaling on Seans original carb needle jet. Premature needle jet "ovaling" is a chronic, widely known problem in older model carbed Ducati-land using BDST38. The end result of the problem is unexplainable rich running, black spark plugs, loss in midrange, usually 10, 15, 20 thousand miles on.

I still can't believe Mikuni allowed this "error" in manufacture.

After much thought, deliberation and experimentation ...I've reached a viable, cheap, permanent, serviceable and simple solution. Though working deep within the slide is very tricky, its doable. Non-invasive, does not require any grinding, cutting or such to the slide. A simple addition of a strategically located spacer, thus offsetting the manufactured "step", eliminating the resultant needle tilt/preload and thus...premature needle jet wear and eventual rich running.

Sean and I have conversed, we've agreed I'll apply the solution to his carbs (mine next!)

10,000 miles from now, an exam of his new needle jets would prove *very* interesting.

Whew! Now that this is conquered, moving forward into the assembly stage.

 

[ducatiman]

4 hours assembling and setup this morning. All done, fully functional, lookin' much better than when they got here

pics, before/after and innards

i'm satisfied they will be functional. Full refurb and my slide mod done, too. I think we got that one solved, needles exiting slide straight and true...a full success there.

 

[Apriliarider]

Those look brand new!! Looking forward to being able to install them and get this project making smoke noise!!......PM'd you @ducatiman. .......sean

 

[ducatiman]

There is some minor evidence of long term corrosion damage, in and out.

I can't claim actual show quality...but can say they are clean, functional and presentable. And setup with great care, ready to bolt up and hit the button.

Darn...I forgot an inline rail filter (as the factory supplies). Its missing but I know the Kawasaki rail filter is perfectly usable.

Got them in stock. I'll plug one into the fuel rail before I ship...on me.

 

[Apriliarider]

Darn...I forgot an inline rail filter (as the factory supplies). Its missing but I know the Kawasaki rail filter is perfectly usable.

Got them in stock. I'll plug one into the fuel rail before I ship...on me.

All Good man. I thank you for that...my plan had been to install an inline filter of the sintered brass element variety upon assembly and installation of the fuel tank....there was no filter present when I removed the tank and lines.