OK, it's for sale. As suggested, someone on here who is known for carburetor work could diagnose and clean/repair/fix your bike's issues.
The #1 (first) thing I suggest is to have a look at the inside of the gas tank. It should be shiny and bright, and of course replacing the fuel filter is another issue, that's easily solved. If the gas tank hasn't been lined with some product like KREEM, Caswell, POR or KBS. a gas tank in good shape to supply uncontaminated fuel is shiny and bright on the bottom-inside and the sides. If it isn't, it needs to be cleaned in satisfactory fashion. A local radiator shop could probably do it, if you don't want to try. The liner products usually come with a pre-liner cleaner treatment. The 'rub' there is, you have to follow precisely the instructions to the system you choose.
Be sure that the fuel sender electric component is
removed and that you fabricate a simple strap steel blank-off plate. Some gasket material will ensure a leak-free blank-off plate. This needs to be done
before any cleaning process is done.
I've had good results cleaning a gas tank of rust with 'cleaning' vinegar,' which is stronger than food-grade vinegar. 6% is what I've used, but you can buy at Home Depot up to 30%. A warning, this is definitely
not a case of 'stronger is better!' Dilute it to 10% or less, down to that 6% I mentioned.
Put the gas tank into an open container, to control any spillage or bubbling-up of the fully-filled gas tank/vinegar. It should be done somewhere preferably outside.
Electrolysis is another very-efficient method of rust removal, and you need to do that also, outside, not inside your garage. Needless to say, this is a 'gas tank out of the bike frame' job. I will leave it to you to research that, People have had fires from doing that incorrectly.
If your tank is rusty, and you spend $ on carburetor cleaning, without cleaning/sealing it depending on its condition, you will again have carb obstructions. The smallest passages are in the jet block, the pilot jets. Contaminated fuel will plug one or more of the four pilot jets.
If the bike is low-miles and in good shape otherwise, it would seem that if your finances permit, going through the system of fuel delivery to solve your issues will restore the motorcycle to safe, reliable, operation. It will increase the value of the bike. A non-runner is not going to sell as-easily, or for as-much as one which starts easily and runs well.
From the pictures, it looks like a great candidate for the relatively easy resurrection of your bike. A sonic cleaner to soak the disassembled carbs is the best way to clean them, my opinion. It's a step above the old carb soak in a can of the orange and blue carb-cleaner (GUNK), in a perforated basket. Berryman and GUNK are still around, but the present formulations have changed because of OSHA regulations.
dannymax is someone who does a thorough job of making the VMax carbs perform as they should.
[email protected]
CaptainKyle is another mechanic who can do the work.
[email protected]
Sean Morley
[email protected] is another person who can set those carbs right.
Do you have any other motorcycle which you ride? If you do, then fixing this may not be as-much of a priority. If you've ridden this bike when it's operating properly, you know its capabilities.
Don't let the carburetion problem prevent you from being able to enjoy the bike. Your brother, may he rest in peace, would be happy to see you being able to enjoy the bike, in its safe, reliable fashion.
Tips on removing the carbs and sending them off:
Drain the float bowls before removal.
The easiest way to remove the carbs is to find the white nylon rectangular box beneath the left side scoop and the removed plastic body piece which holds the electrical relays. They can all stay connected, just carefully remove them from the black plastic plate and hold them aside.
Two tiny phillips screws hold the top onto the white plastic splice box where the two upper throttle cables connect to the lower two throttle cables.
Be very careful when working on this white plastic connector box! It's no-longer available.
Carefully remove the plastic connector box, allowing the throttle cables to now be disconnected. You will see they have small rectangular white nylon blocks which hold the top cables to the bottom cables. Unhook one, then turn the nylon block 90 degrees from how it lays, and you will see the cable will now be able to be removed completely. Once it's released, you can now see how the other half of that upper and lower cable can be separated from the rectangular small cable connector. Repeat for the other upper-lower cable. You now should have two disconnected upper cables and two disconnected lower cables. The lower cables are still attached to the cable bellcranks in the middle of the carburetor blocks. They're spring-loaded at the carbs, you don't need to touch them further, or to disassemble them anymore.
Removing the carbs should be done with care, as a ham-handed attempt may crush or crack a carburetor body as they're made of potmetal or German silver as it's also known. I usually use a small prybar, something less-than 2 ft, and one end rests on a frame member, while the prybar closest to me finds something substantial on the carb body to lever-against. The airbox was already removed, yes?
Making sure that your prying is not going to break/crack the carb body, lever upwards and you will feel/hear the carb 'pop' out of the rubber boot. Now try to pull upwards on the other carb which is next-to that removed from the VBoost rubber donut, and carefully pull upwards until it too pops out of the rubber donut. With two carbs out of the VBoost rubber donuts, the last two should be an easy pull-upwards, being careful about the carb's integrity. A bit of snaking out of the frame tubing and electrical wires, and now you can easily remove the gas line.
A quick word on the gas line, if it's original to the bike, it should be replaced, as it could be shedding material internally into the carbs, and possibly be contributing to the fuel problems.
Make sure that the carburetors are completely empty of gasoline, and you're ready to contact the guy you've chosen to send the carbs to for shipping instructions. Pad them well in a box big-enough to allow their secure shipment. A 'box in a box,' with some bubble wrap around the carbs, and more bubble wrap or crumpled-up heavy shopping bags would work well.
Putting the carbs back in-place is another
be careful how you push/pry on it situation. I offer a thread, this works for me.
https://www.vmaxforum.net/threads/1989-vmax-resurrection-thread.53264/page-2#post-535165
Hooking up the carburetor cables is actually pretty-easy. You
did mark them didn't you? Rest easy, as long as you didn't do anything at the handlebar throttle in the way of cable disassembly or throttle tube removal, you will be all-right. The cables will actually only easily attach in the same way they came-off. Use those small withe plastic nylon rectangular blocks to re-connect the cables to each other, and to place them back into that larger white plastic junction box. Be careful not to over-tighten the tiny phillips screws! It's easy to do if you're not careful.
Check for proper operation of the throttle cable. The push/pull two cable pairs should not hang-up, or should not fail to fully-close. Careful re-positioning of the nylon junction box for the throttle cables will allow its proper operation.
I think I've only encountered one bike which had frayed cables, so if in your work you find that to be the case replace it.
Choose your cable to be routed from this part of the factory service manual, in the Appendix at the end of it:
https://ia800204.us.archive.org/14/...ice-manual/yamahavmaxvmx12-service-manual.pdf
You can return your bike to good operation. Take your time. Read through what's been contributed via the thread. Ask questions, and undertake your work with confidence in doing things well. As Eric Burdon of the Animals said in his song
San Franciscan Nights, "it will be worth it!"
