Search found 20 matches

by stian buksa
Thu Aug 16, 2012 1:58 pm
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: woodruff key replacement
Replies: 0
Views: 5080

woodruff key replacement

Does anybody know if the woodruff key on the RH side of the crank (the one that holds the rotor, part no 0755.29.190, 4x4x35mm) is a standard issue I can get at a local shop ?
Or do I have to order it fram a classic ducati parts dealer and wait the two weeks it take in the mail ?
by stian buksa
Thu Aug 18, 2011 9:28 pm
Forum: Engine & Transmission Shop
Topic: Shims
Replies: 9
Views: 4018

measured pre load: How tight ?

I've found two methods of finding the correct amount of crankshaft pre-load described on this forum: "The generally accepted preload on the cranks is .05-.10mm[.002"-.004"] You should feel some drag but the crank should fall on its own when the heavy part of the flywheel is up" - wdietz186 "To do it...
by stian buksa
Tue Aug 16, 2011 7:26 pm
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: pre load: How tight ?
Replies: 2
Views: 5781

pre load: How tight ?

I've found two methods of finding the correct amount of crankshaft pre-load described on this forum: "The generally accepted preload on the cranks is .05-.10mm[.002"-.004"] You should feel some drag but the crank should fall on its own when the heavy part of the flywheel is up" - wdietz186 "To do it...
by stian buksa
Sun May 08, 2011 2:54 pm
Forum: Carburettor & Fuel System Shop
Topic: 5cc pr 20 squirts
Replies: 3
Views: 1997

5cc pr 20 squirts

How do you accuratly measure the accelerator pump ? I tried to use a small cup on the engine side of the carb to catch the petrol while i yanked the cable, but couldn't help to miss a little. The piston was hit by a drop or two, giving a wrong result Then I took the cable and piston off, and activat...
by stian buksa
Tue Nov 30, 2010 8:13 am
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: Longer rear shocks ?
Replies: 4
Views: 6070

Longer rear shocks ?

I am considering changing my rear shocks (on a 72 GT) to longer than the 305 mm marzocchis originally fitted to get a more sporting, aggressiv turning bike I have seen mentioned somewhere in this forum that it is a pretty common change (but I cant find the post now) and road and race sell longer cen...
by stian buksa
Tue Aug 17, 2010 8:44 am
Forum: Carburettor & Fuel System Shop
Topic: 32mm PHF Dellorto stock specs for needle and jets?
Replies: 23
Views: 9048

I've read the article, and it is really interesting. But as it is from the mid 70s I wonder if modern coils still need a ballast resistor and condenser(s) ? I see in the follow-up article that one ballast resistor is sufficient I also wonder if the standard charging system can handle the higher powe...
by stian buksa
Fri Aug 13, 2010 6:42 am
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: balancing crank with new pistons ?
Replies: 10
Views: 5677

balancing crank with new pistons ?

I rebored my -72 GT 750 this winter and changed to 81mm Ø pistons. Now it vibrates more than before, and I wonder if I need to dynamically balance the crank. Has anybody experienced this, or may the vibrations come from something else ? Also does anybody know the recommended balancing factor ? Stian...
by stian buksa
Thu Aug 12, 2010 4:49 am
Forum: Carburettor & Fuel System Shop
Topic: 32mm PHF Dellorto stock specs for needle and jets?
Replies: 23
Views: 9048

change of coils

A bit out of topic maybe, but... When you change coils what kind of coils do you change to ? I've been looking at high output coils, the kind Steve sells or car HO coils, but I'm afraid that the alternator wont handle the higher power consumption. Its all ready struggling at low rpm with lights on A...
by stian buksa
Tue Aug 10, 2010 1:12 pm
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: electronic tacho
Replies: 1
Views: 2377

electronic tacho

Does anybody know what "feeds" the electronic tacho ?
I have checked the wiring diagram and its not there.

My tacho has started to swing a lot, and being fairly inaccurate. Does anybody know how to make it work better (except from changing to a mechanical tacho)
by stian buksa
Thu Jul 15, 2010 2:36 am
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: timing marks/TDC
Replies: 2
Views: 2866

timing marks/TDC

I find it really hard to find TDC on the rear cylinder to set the ignition. Tried the "feel the piston" method, but that gives me +/- 5 degrees or so accuracy. Shouldn't it be possible to use the timing marks on the beveldrive for this ? I know they don't align at TDC, but does anybody know exactly ...
by stian buksa
Thu Jul 15, 2010 1:18 am
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: roundcase gearbox explained, please
Replies: 5
Views: 3460

Finally finished my rebuild, and it seems that Machten was spot on and the gear selector box was badly adjusted

Works like a charm now :-D
by stian buksa
Thu Jun 24, 2010 1:53 am
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: carb tuning for 1974 Ducati GT750
Replies: 5
Views: 4486

Mick Walkers "Ducati Twins Restoration (Motorbooks Workshop)" has a table of the settings of all the carbs of the ducatis, and Ian Falloons "Ducati bible" also has some tables If you don't have access to the books, you probably can view them on google books (I did) My bike (71/72 roundcase gt) was f...
by stian buksa
Tue Jun 15, 2010 7:42 am
Forum: Roundcase Engines > 750 GT, 750 Sport & 750 Super Sport
Topic: valve guide lengths
Replies: 1
Views: 1653

valve guide lengths

I have bought new valve guides for my 72 roundcase 750 GT, but I'm uncertain if the length is right. The ones that was fitted was cut really short, and not original, so I cant really use them for reference Does anybody have any original/workable valve guides so they can measure them for reference fo...
by stian buksa
Mon Jun 14, 2010 12:00 pm
Forum: Wheel, Brake & Tyre Shop
Topic: Brembo 12mm master cylinder with single F08 caliper
Replies: 5
Views: 2602

lockheed caliper

Has anybody tried combining a 12 mm brembo with a lockheed caliper ?

I see very little mentioning of the lockheed calipers fitted to the roundcase GT. Is that because its a bad caliper, or is it simply because it is rare ?
by stian buksa
Wed Jun 09, 2010 3:48 pm
Forum: Engine & Transmission Shop
Topic: Shims
Replies: 9
Views: 4018

without micrometer

Any tips to how to measure the crankshaft preload without fancy instruments ?

With 0,50 mm shims i can feel that the crank is a little "loose"
With 0,60 mm its tight, with a minimum of drag
With 0,75 mm its tighter, with more drag

Which one should I go for ?


71 750 roundcase GT

Go to advanced search