Already on the first day following repeated and similar cases of breakages, a functioning defect was discovered with the Castrol supplied oil mixture which left gummy residual sediments on elasticated materials.
At the end of the first day the MZ of Willamovski was first in its class despite the evident functioning problems and the men from the DDR would have been happy to substitute the fuel in the tank but this was denied by the international jury, showing unjustifiable rigidity in the application of the rules.
To bring pressure to bear all the MZ and Simson teams retired officially, accusing Castrol of sabotaging the team and throwing a dark shadow over the entire event.
The German technicians claimed that the oil supplied was not that requested and caused the engine breakages.
An accusation of this kind on American territory caused powerful argument and almost a diplomatic incident.
Some days later Castrol recognised their involuntary error due to an incredible difference between the oil made in the UK and supplied to MZ for more than 15 years, and that in the US which was the subject of the scandal. However, the damage was done.
Italy, which in those years could count on a large group of excellent riders on first rate bikes like Gilera, KTM and SWM, entrusted their fate to the official teams of these three brands, but the central goal eluded them.
The retirement of Capelli and Saravesi’s fall that broke 2 ribs on the second day the prejudiced their well-founded hopes of being among the prizewinners in the Trophy, where KTM Andrioletti, Capelli, Ferrari, Foresti, Saravesi Taiocchi classified in 9th place.
Also in the Silver Vase, both teams were delayed by the withdrawal of Paganessi and the fall of Radici and were kept away from the podium. The SWMs of Mercatelli, Pier Luigi Laureati, Radice and Rottigni were placed 7th, followed by the Gileras of Brissoni, Gritti, and G. Paganessi Signorelli in 8th spot.
At the end of the intensive week, came up, once again and for the 4th consecutive year, the Czechoslovakian Jawa, ridden by Cemus Mrazek in the 250 class, and Masita Cisar - 350, and Cespiva Fojtik - 500.
England managed second place, followed by Austria, at 4th came West Germany. U.S. 5th, 6th were Sweden, Holland 7th, 8th Belgium, Italy 9th, 10th° France, Canada 11th and 12th, although withdrawn, the DDR.
The Silver Vase was claimed, surprisingly, by the Americans on Husqvarnas: Dick Burleson - 175, Malcolm Smith - 250, Ed Schmidt - 501 and 350 Ron Bohn, who had the merit of conducting a good race, but also a chance to see all their potential rivals fall victim to unforeseen mechanical failures or ruinous falls.
Behind the hosts were placed Sweden, Czechoslovakia, 4th Holland, West Germany 5th, 6th Belgium, Italy B were 7th, 8th Italy A and Czechoslovakia A, 9th.
Of the 303 riders entered at the start, only 176 crossed the finish line on the sixth day, being awarded 106 gold medals, 38 silver medals and 32 bronze.

1974 - After the troublesome American episode, in 1974 the ISDT was in its 49th edition and it returned to Europe to Camerino in the Abbruzzo Appenines in central Italy from 9th to 14th of September, although here too on the other side of the ocean problems persisted.
The extreme difficulty of the confrontation was emphasised by the political rivalries of the two opposing blocks, east and west.
This extended to the competition commissars and their debatable interpretations of the rules.
At Camerino too the ISDT was not free from this ominous trend and was characterised by many contestations, table changes and jury meetings but also practical problems such as increased fuel prices and insufficient parking space.
One of the principal protagonists at the event, Zündapp, was against the jury’s behaviour but also protested at the accidents caused by local riders who freely travelled over the route stages, often travelling in the wrong direction (a Zündapp rider was injured in an accident of this type). Zündapp withdrew in protest on the Thursday morning, declaring it was too dangerous to proceed in the competition.
The 1800 km route wound between some rough paths of the Appenine Marche region, putting severe strain on personnel and equipment.
Italy was playing at home and could count on ten very good riders in the saddles of ten excellent two stroke Gilera machines with direct assistance and material from the manufacturers, backed by the four official KTMs of the Italy B team in the Silver Vase event.
From the start they were the favourites but once again the pundits were disappointed.
There were splendid individual efforts with two firsts, two seconds and two third class places, both the Gilera teams came close to victory but could not clinch the result and settled for 3rd place in the Trophy and second in the Silver Vase.
In the Trophy event, for the 5th consecutive year the Jawas of Stodulka, Cemus, Masita, Cisar, Fojtik and Cespiva prevailed, followed into second by Sweden, Italy 3rd (Andreini, Brissoni, Gritti, Oldrati, Saravesi and G. Signorelli), the US came 4th, 5th Holland, 6th DDR, 7th Poland, 8th Great Britain, 9th Switzerland, 10th the Soviet Union, 11th France, 12th Canada and 13th Belgium.
The superiority of the Czechs was further confirmed by the victory of Milan Jedilcka, Cihalka, and Jaroslav Josef Rabas Briza. Hot on their heels were the Italians (Bettoni, Gagni, Miele and Sala), followed by Czechoslovakia, 3rd, 4th U.S., Austria 5th, 6th Holland, Italy 7th B (Andrioletti, Ferrari, Taiocchi, Testori), 8th West Germany, GDR 9th, 10th B West Germany, 11th Sweden, 12th Great Britain B, 14th Spain, France 15th and 16th Belgium B team.
Unfortunately, some overt favoritism by the jury (the whole world is one country), risked compromising the purity of this racing, and other issues.