For the new owners:
https://www.vmaxforum.net/threads/new-vmax-owner-faqs-new-members-please-read.21240/
Print-out this factory service manual, and put it into a 3-ring binder. It can save you thousands of dollars if you use it. The format is a bit confusing, Yamaha has 'supplements' for different years models, showing updates when changes were made, or service data being changed. Those supplements are located at the front of the 405 pp. manual. You just have to look for the title page for the supplement, and then look at the copyright date to see for what year's model that info applies. Look at this thread for more info on that:
HOW TO: Errors in official manuals preventing proper HOW TOs
The factory service manual:
http://vmoa.net/VMX12-Service-Manual01.pdf
Issues in handling, I would check that your front forks have air in them, roughly 5-15psi depending on your weight, and if you have a passenger frequently. Be aware a popular mod for the front forks, Progressive Suspension springs says not to run air with their springs. The only way you would know that is if the prior owner swapped-out the OEM downtube fork springs, or you disassembled the forks to check for oil volume, or to replace a leaky fork seal. If your downtubes are showing peeling, pitted chrome don't bother replacing your fork seals, as they will soon leak again! The peeling, pitted chrome will ruin your new seals quickly. Replacement downtubes are either a good used replacement from CaptainKyle
[email protected] or Sean Morley
[email protected] or another member here, who advertises some for sale. But, NO PITS or PEELING CHROME! Race-Tech sells replacement downtubes for ~$200 apiece, so $400/pr. Forking by Frank recently moved to Alabama, I think it is, I dunno yet if they are up and running for sales, I've used 'em in the past for downtube replacements.
Also check your forks for proper tension on the steering stem, the 'fork flop' is one way of testing, either youtube for Sean Morley's video, or someone else's. If you feel tiny little bumps as you turn the forks side to side, you've discovered 'brinelling,' pitting of the steering bearing races, usually due to too-many hard landings from wheelies, and lack of adequate grease as a contributing cause. All Balls has a steering head bearing set or go to a dealership website for the needed replacements, including the pressed into the steering head stem, outer bearing races (OBR). The top OBR will come out using a long drift punch, from the bottom, and catching the lip of the OBR in the top of the steering stem. However, the
bottom OBR does NOT present a sufficient lip to do the same thing!
Two ways to do that:
1] put a bit of bead weld on the roller bearing surface of the OBR, to give you something to pound against. Actually, you need to build a weld bead 180 degrees apart, so you can alternate tapping on the weld bead, to drive out the OBR. The heat of welding also helps.
2] use something like a Dremel to cut one or more places on the OBR, and then use a chisel or punch to drive-out the loosened two pieces.
Check your rear shock settings, there is a set of 4 damping settings on the top collar, and 5 settings on the spring pre-load on the bottom spring keeper. Set both sides the same, top and bottom.
Also check the torque on the swingarm nuts. At the end of the factory service manual (P8-10 and 8-11, pages 381 and 382 of 405 pp. on the .pdf page counter) is a torque chart, and # of fasteners, and nut/bolt dimensions for your bike. This is a very-handy thing to put into a plastic sleeve and have handy to refer-to, somewhere in the shop.
Worn tires and over-or-under-inflated tires, or mismatched tires are probably the biggest source of handling issues. I continue to say that going to radial tires is the #1 best handling improvement you can make to your VMax. Usually a rear wheel swap is required; the VMax spec's a V-rated tire (to 149mph) and any 15 inch radial motorcycle tire you find are probably rated at H (130mph). Don't even get me started about car radial tires on a motorcycle! That is called 'The Dark Side,' and that's not what you need on a 110+ horsepower motorcycle capable of nearly 150 mph.
The wire chart is for 1985-'89 bikes, there was a change in 1990 to another type of CDI box, using fewer leads and a single pick-up coil. later there was a change to a different regulator/rectifier, which added a ground wire where the R/R to that point used the mounting of the R/R to the left rear footpeg bracket as its ground.
I could go-on, but use the search function here and find info of interest to troubleshoot your ride, and how to improve it.
