Have you checked the engine mounts for integrity and that all mounting bolts are at the correct torque? (p3-79 of the Service manual
Good advice, though referencing chapter 3, p. 79 of the service manual might be a more-precise reference. I might find myself trying to figure-out,
"now where in the tarnation between p. 3 and p. 79 is that?"
Using the .pdf page counter, it's p. 203 of 405 pp. The page count on each page is first the chapter, in this case, chapter 3, and then the page in that chapter, page 79. It reads, 3-79. No chapter prefix, no page prefix.
For anyone using the service manual for the first time, the first 64 pp. are annual model updates. It is a good idea to see what's in there, as the updates supersede prior info listed form the service manual first published in 1984 for the 1985 model year. Annual model numbers are indicated by a letter after VMX12, then a letter.
If you use a fiche page online, you can see by each year, what the letter suffix is. An example:
Yamaha 2007 Motorcycle OEM Parts, Ron Ayers
Then look for VMax, the CA suffix is CARB-compliant motorcycles for the State of California. Here's a non-California example, then a California example:
Here is the 1985 model:
Unless otherwise indicated, any 'running change' as-of a date/model year specified in the supplement for that date, is in-effect for any subsequent model year (following model years). That's a good thing, as your bike after that date has the 'better' part(s). Part numbers also will be changed to reflect a change, but the fiche picture
may not be updated! 1985-1995 models used a front of the frame cross-brace which is
straight-across, and the internal oil filter, with the external cast-aluminum housing oil filter.
The 1996-'07 models use a
curved frame cross-brace in the vicinity of the oil filter. However, if you look at the Ron Ayres fiche of the frame, it uses a picture showing the straight cross-brace, not the 1996+
curved frame cross-brace. At this time, if you look at the frame cross-brace part numbers, you will see the 1995 and 1996 part numbers are the same. It's possible that if you order the cross-brace using this part number for your 1985-1995 bike, you will receive a
curved frame cross-brace. The curved frame cross-brace will fit any Gen. 1 VMax, 1985-2007. The
straight frame crossbrace will only fit up-to 1995 model year, assuming you use the old-style cast-aluminum oil filter housing. There are adapters to allow the use of the more-modern style oil filter which is self-enclosed, and which does-away with the cast aluminum early VMax oil filter housing.
There are also adapters and remote location oil filter brackets, if you want to do that. I think K.I.S.S. is the best practice.
There is also a thread (or threads) on errors in the factory service manual. Those are good to be able to recognize.
https://www.vmaxforum.net/threads/how-to-errors-in-official-manuals-preventing-proper-how-tos.44668/