Quartararo has intermittently suffered from arm pump throughout his premier-class career, with the Frenchman famously plummeting from first to 13th in the 2021 Spanish Grand Prix.
Yamaha has made a number of changes to its M1 challenger over the past 12 months and, while Quartararo has repeatedly hailed the Japanese marque for bringing new developments, he feels one unintended consequence of the overhaul is the added weight in cornering.
The 25-year-old already complained about arm issues at Jerez last month, but things only got worse for him last weekend as he struggled to make the bike turn at Mugello, dropping him from 15th on the grid to a point-less 18th place.
Asked to explain his dismal showing on a track in which he had looked strong in Friday practice, the 2021 champion said: "Especially from mid-race I had an issue so I could not really ride. We have to improve this area because it's not arm pump.
"It's just that my arm is clearly on the limit in this kind of tracks, so we have to find a solution.
"The grip that we are missing and the engine that is pushing us wide is making the bike super, super heavy.
"The number one priority right now for us is to find back the feeling we had in the past, especially on the change of direction."
Quartararo feels the onus is on Yamaha to fix the problems with the M1, ruling out the role of his own fitness for the arm issue that plagued him at Jerez and again at Mugello.
He has already undergone two surgeries on his arm, first during his rookie 2019 season and then again in 2021 in the wake of that year's Spanish GP.
"It's difficult. After Jerez I have the same [problem]," he said. "I already twice had the operation. Everything looks fine.
"But the problem comes, basically I have no space [in my arm to manoeuvre]. My muscle after the mid-race was clearly on the limit, so I don't know what to do right now.
"I think I'm training in the best way as I've ever trained."
Quartararo doesn't believe there is a wider problem with modern MotoGP being too tough on the body, saying: "No, because last year we had no problems.
"I think the way we did our bike this year something has been wrong because even if you are making steps forward, from the beginning of the year we feel that the bike is super heavy and we have to adjust it.
"So we have to find what is the main thing that is making this bike [tough to ride]."
Rins' race was also hampered by the same problem, as he could only salvage a 15th-place finish after lining up 10th on the grid.
The Spaniard revealed that he felt dizzy in the immediate aftermath of the race, as he tried to recover from a tiring 23-lap contest around the Mugello circuit.
"I was struggling all the race," he admitted. "I just lost two positions on the start. And then lap by lap I tried to be there, I tried to manage the bike, I tried to manage my physical condition because right now our bike is quite hard, it's quite critical.
"I'm also destroyed. When I got back to the garage they had to help me because I was a little dizzy. With the bike right now, with the problems that we have, everything gets harder and it's very physical.
"You have to give more from yourself to patch the problems."
