Bosch BTZ Boxs Differances

V

Vince

Hero member
Whats the deal with specific part numbers with these box's.Are they all the same and usable on different marks or specific part number box's needed for different bikes,was curious after reading the spin out thread if you get my drift.Can you use a Laverda box on a Pantah for example
 
I was thinking advance differences maybe .Been told there is no difference and also told there bike specific from reasonable sources.
 
As grant posted in another thread, there are BTZ boxes with different numbers on them.

My guess is that they have different advance curves. I can't find any technical info on either of the Bosch numbers though. So no idea what the advance curves look like for each box.

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Not much info on this.Why I asked is I was looking at a lack of off idle power on my Pantah.I checked its timing with a strobe and it looked like it wasn't going to full advance.A bloke on the Pantaheads list offer to have a look.He found it would go to its first advance at 1700rpm but nothing after that,OR SO WE THOUGHT.We then went into the air gap rabbit hole attempting to get it to go to its SUPPOSED full advance at 2800rpm.Acording to the list where it should happen.We tried a bigger gap,no result and then a smaller gap and that changed it a bit.Pain in the arse job,draining the oil and you need brass feeler gauges because of the magnet.I then asked one of the blokes at the local Ducati shop and he tells me the Pantah boxs have a 3 step advance and full advance happens at 4000rpms.
So first jump is 1700rpms,2nd is 2800rpms and full is 4000rpms.We were just not reving it enough to show the full advance.Wasted 2 days doing this stuff.BTW I found a reference to Bevels having this 3 step advance as well.Maybe why there Bosch systems work a bit better.
We had a discussion about 2 or 3 step advances and for some odd reason no one else had a 3 step advance,most were not in OZ.I have no idea why the rest of the world got 2 step advances and according to the local pro,he said all Pantahs had 3 step advances.Mine is a TL so maybe that got 3 step?


 
G'day Vince

My Bevel Duc runs a lot better with the Ignitech than it ever did with BTZ. It uset to have a huge flat spot on the transition just off idle. I've almost eliminated the hesitation entirely just by mucking about with the advance curve (seems to like an early advance).

Idle mixture a bit on the rich side helps too. Gives it a little extra fuel before the accelerator pumps cut in.

Cam
 
Ended up fixing it with a new vacuum gauge.Seems I should have stayed with the std idle jets instead of the recommend smaller ones.The new gauge clearly showed even cylinders at idle and cracking the throttle but roll it on slowly and the front cylinder did nothing till after a 1/4 turn on the throttle.
Go to 3 turns on the mix screw from 1 1/2 and then both would work evenly.Not perfect but way way better.
 
Vince
Let us know what number box you want if you need to try, got a few here so maybe can find you something here.
My mates Hailwood runs the same box as Lav's as when we killed one of his, pinched one of the defunct boxes off the Exec, same number and all was good again plus saved a few pounds of weight on the Exec.

New Vacuum gauges hey... did you happen to use your old ones on your 3C before the Snowy run ????


 
Obviously your best bet is to go to a Ducati forum, i cant help you here but i will say your (034) boxes will give you 9 degrees at 900rpm, 16 degrees at 1800rpm, 28 degrees at 2800 rpm and 32 degrees at 4000 rpm. this is achieved via stepped rotor on the crank.


Paddy said ducati !!!!! Kill Kill Kill  :o
 
However clever those boxes are/were they have reached the age in which they are starting to fuck up. I've had the distinct pleasure of going through all the known weaknesses of that certain other brand [D] to arrive at the conclusion of a farked ign box. It seems a stage or two in the advance curve can go AWOL on occasion. There just aren't any constants left to assume on this old crap anymore no matter how much we love them. Other than maybe Orange Jotas
 
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