BlueSky

I would look at the vacuum passage that pulls the diaphragm.

Funny stuff! I decided that the preparation might kill an old man so I cancelled my appointment. Then they did the Cologuard thing instead.

These bikes are notorious for the spark plug wires corroding where they are connected to the plug caps and the coils. Unscrew the spark plug caps and see if the copper wire cores are green with corrosion. If so, cut off a half inch or more to get to clean copper wire and reinstall. Or replace the wires. Also, check the caps for resistance. Should be 9k to 10k ohms if stock. NGK replacements are typically 5k ohms. You may have a spark problem instead of a carb problem.

I would use penetrating oil in the cylinders and let it sit for a while.

The ones Prairiehammer found are cheaper.

You may or may not ever find any more new bushings.

Is this it? https://www.ebay.com/itm/YAMAHA-83-87-XVZ1200-XVZ-1200-VENTURE-ROYAL-REAR-UPPER-SUSPENSION-ARM-BUSHING/123657085751?epid=8029476876&hash=item1cca896337:g:fBEAAOSwC6haposJ

These flashlights on a head band are great tools. They light up what you are looking at leaving both hands free. I have several I use around the house. https://www.walmart.com/ip/Energizer-Vision-HD-LED-Headlamp/47327204?wmlspartner=wlpa&adid=22222222227034524794&wl0=&wl1=g&wl2=c&wl3=56110376018&wl4=aud-566049426705:pla-87761035298&wl5=9010078&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=47327204&veh=sem&gclid=CjwKCAjwxrzoBRBBEiwAbtX1n1hjUWNpvugarPiMYuDGAoNbl6gomUqQRg7lr372CBaSeAL_5oSdfhoCD4gQAvD_BwE

Cha's problem was that the files were too large. He reduced the data size of the photos and they posted.

That sounds like a great find with such low miles. Should last someone a long time. I don't consider my 07 RSV top heavy either and I also have a 29" inseam. I think that model has 75hp instead of the Venture's 98hp if that matters.

Some starter fluid would get you past that first hard start if you are on the road. 140,000 miles, when did you adjust the valves last? I would check the compression just for fun. And checking the exhaust temps with one of those infrared thermometers would tell you if a cylinder is not working as hard as the others. Your problem may be electrical but if the bike is not up to snuff mechanically, it will contribute to the issue. Just thinking and wild guessing.

Maybe the file is too large. Try reducing the file size and retry.

check the carb holders and everything else for vacuum leaks.

My manual goes up to 93 and the pickup coil info is the same as what you quoted for 86 to 93.

Tire stores used to use a patch that had a plug in the center of it to plug and patch a tire at the same time. I have looked on line for those and can't find them. Don't know if they are still available? Yep, they are available. Just looked again. https://www.zoro.com/steelman-tire-repair-patchplug-combo-18-pk25-jsg381/i/G9656090/feature-product?gclid=Cj0KCQjwi43oBRDBARIsAExSRQHTeaE6_GfVqRqfNgHmONK1iDE6ui5-Z__vEPWsNtLA0m3ZZeNo22UaAlioEALw_wcB

Why not use CO2 inflators? Those little compressors may work on a motorcycle tire but they take a looonnng time to pump up a car or truck tire.

Are you sure it's running on all four cylinders? Check the exhaust pipes temperatures to see.

I doubt that you need to worry about that. My Dodge Magnum brake rotors rust quickly if it sits for a few days and the pads make a light scrubbing sound when I back out of the driveway and brake. But, it has 115,000 miles on it and the brakes are original. Yeah, it's time for a brake job but they have really lasted especially for a heavy powerful car like a Hemi Magnum.

I'm not sure what bolts you are referring to? I just took a look at mine. Are they exposed so that I can remove one to check without removing anything else? Christmas before last when my wife asks me what I wanted for a present, I gave her a couple of links like this for SAE and Metric bolt size determination. https://www.ebay.com/itm/Thread-Checker-SWTC-S21-Thread-Testers-Gages-SAE-INCH-ONLY-Male-Female-NC-NF/310993375445?hash=item4868a650d5:g:DYQAAOSwDmBY47US

It might be interesting to cut the filter open and see what is inside.

Isn't the overdrive a 0.7 ratio? 3.55 x .7 = 2.485. Seems to me a reasonable ratio for highway driving. Does he have a means of reprogamming the speedometer?

Don't you think he should be careful what "carb cleaner" is put into the tank? I recommend Gumout for high mileage engines with PEA fuel injector cleaner. It works and it doesn't harm the carb. I'm sure there are many others.

Is fuel pouring out of all four carbs? It's probably due to the fuel needle leaking. Be careful. You don't want to hydrolock the engine. I agree with draining the carbs maybe several times to see if the crud under the seat will flush out.

The shops in Homestead FL when I was there charged $150 for the rear if it was shaft drive and $75 for the front if they removed the wheels from the bike. At the time I paid it because I was working and was very busy and didn't have the time or initiative then to tackle them myself.

Thanks but HF doesnt' sell that bead breaker any more. This is the one they sell now. https://www.harborfreight.com/bead-breaker-92961.html