1970 Ducati GT 750
Recently I completed a 1970 Ducati GT 750 set of heads. The heads were repaired so many times that the seat had recessed too far. In addition to that challenge, one head had cracked and the seat was loose.
Here’s a brief overview of what it took to restore this classic motorbike:
- Evaluate how much the new valves should protrude into the head.
- Remove the old seats from the heads and prep them for the new seats. That includes repair to the cracked head by welding, then polishing (shown later).
- After prepping the cyclinder heads, I determined that available aftermarket and OEM seats did not have the needed dimensions. In particular, the “thickness” between the outside and inside diameters were insufficent for the valve size being used. Being a machinist, this challenge was surmountable, by ordering round stock of berylium copper and making custom valve seats.
- With my new seats ready to go. Next came the boring of the head and Note the repair to the cracked head and valve seat of the rear cyclinder.
- Then off to the regular seat maching process. I used a 1.3mm wide seat as this is no racing bike and reliability is important.
- The result was awesome and what would be “throw away vintage parts” are now back to life for another 40 years.