Patch

Typical chapter 7 http://braindump.donfick.com/media/9d/Yamaha%20v-Star%20650%20Shop%20Manual.pdf

Assume you are referring to Bum's issue? I for one cannot ignore the heat relation in the mix and really, I have a difficult time ignoring that this excessive localized heat is not friction related! Nor can I either see that a missing something in the hydraulics would only show up when hot or over heated...hmm

I don't see that you are having the same issue for the same reason. This reads like a displacement issue or a push volume deficiency (trying to find a simple explanation) The fact that the clutch engages a couple of mm off maximum proves what I mention above! 1st to 2nd "harshly" says the clutch is still in friction. You need to disassemble the hydraulics from the slave to the master, clean, repair and replace worn parts then refill and bleed with quality dot3! The switch is not at the moment in question! In Bum's case there is an intermittent switch issue which seems to be heat related. First thing to accept is that there is/may likely be a ground issue but, because it is only when the bike is hot we need consider that the switch housing deforms enough under heat (due to wear) causing the ground to not complete the circuit! In Bum's case we assume because of his repeated posting that the hydraulics are in good condition and, based on his experience in the field we are looking past the hydraulics! Again I think running seafaom thru the crankcase is a suitable start here, not the complete answer tho but any change in behavour may disclose a clue. Yours truly

Before this goes any further let me mention a couple of points from my point of view: You do not need to defend your decision! Your bike your way, my motto and belief! You did not claim ( that I read) this to be a more efficient metric for this or any bike! Now that said the numbers you and others do post tell the experienced gear heads this is in fact an inefficient kit! Efficiency builds power whether its to be measured in torque or HP both of which are primary goals set by the builder or modifier! Even tho I have not held or played with the setup mentioned, it has been very clear in the reacquiring issues we here have read. This adapter is so poor in design that in my opinion is not fit for a lawnmower! And at this point I do not care who does or does not agree with me on this opinion! It is a collection of a mess, period. What is going on with that adapter is a cycle of lean to rich, caused by pooling and separation. If that was installed on a say barely broken in engine you could start the countdown to its premature end! Mikuni while many perceive as arrogant to deal with, are not inexperienced, nor do they guess at the manufactures requirements when they set out to design a fuel delivery system! So, if we want to beat them at their bread and butter we need to at least flow the math.. Anything else is hearsay. My final thoughts on the subject Patch

That tho is not the whole picture; you used an adapter to install the carb. Patch

Its not about dyno numbers, it is about flow rates! The more I read these days about cheap fast fixes the less thought and basic performance principles are actually being shared. Everything about combustion engines is about air flows; how to manipulate air flowing in and out is the game, how much and how fast or where to speed or slow it is the aim. Mixing fluids then delivering that metric to the chambers takes more thought then simply bending and cutting tubing and welding's that are so poor in quality at least in the examples we seen posted. Understanding pressure differentials also seems to be lost. Knowing the filling potential of the available displacement is the first step always; then you move thru the rest. Performance machines such as motorcycles have a long power range, knowing how changes will impact the range and at what rpms requires modeling then, those posted numbers are suppose to be the reasons we crack our wallets open, no numbers, no coin exchange. A quick search brought up several supplies of kits and parts bee is just one Patch https://www.ebay.ca/itm/Motorcycle-Carburetor-Repair-Kit-Main-Jet-Sub-for-Yamaha-VMAX-V-Max-1200-VMX12/113753550982?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3De1d5d47c6b064ba88808147c48229185%26pid%3D100005%26rk%3D2%26rkt%3D12%26sd%3D142418886727%26itm%3D113753550982%26pg%3D2047675&_trksid=p2047675.c100005.m1851

And I would like somebody to put some real numbers down. "plenty of power" compared to what? Seriously you couldn't find jets or clean them, replace some gaskets?

Yes Sir HAPPY BIRTHDAY from Gods country Carl! A little dye on your whiskers and you would still look like your old self, just like the picture we see hanging in the post offices around here: WANTED;)

Well Buddy at 9:28 here in Calgary is sundown. I know I have a cold one in the fridge and at sundown I will crack it, and toast to your friend Martin! Cheers

Man you Ontario guys always testing a Frenchmen comprehension eh. Now I'll tell yall up front, if any of you guys think I'm going to look for the cord to turn the wind, let me assure you I have and it aint where yall say you last saw it!

Yep that's a good one! And behind a good mans broken heart, you'll find one there too;)

Maybe cause of the swelling? You know like how we age and retain water causing us to thicken;) I read somewhere, in some bar, in some boring town, that steel does the same old thing, but thru heat and will even at a young age; go figure

Venting the crank is best done at the manifold mounting plate as close to center as you can. You may run into accumulation problems with this design which would effect the valves; meaning a trap before the carb adapter is likely a good idea. Vent the crankcase or it will make several vents on its own and each one will be a leak. With port 2 you may use it for vacuum monitoring such as a permanent dash mounted gauged. Patch

Here is a link to Amsoil, just as a reference https://blog.amsoil.com/dot-3-and-dot-4-brake-fluid-whats-the-difference/

So Bum here's my thoughts and maybe a question or two.. I went thru the overhaul section of the manual and I could not find an inspection port for an oil pressure reading??? That wouldn't stop me from rigging one if in your shoes tho. One note I read over and over is "look for oil clotting" hmm. So I ran some sea foam thru my 6lt when I was doing some upgrades last fall; it proved to dissolve clots pretty quick cause I blew out a high pressure switch which was suspect also noticed my oil chambers feeding the hydraulic injectors were in better shape afterwards say withing 200 klm.. So I would run a full can thru the crankcase! I'd also take it slow swapping out the filter next time looking for signs of clotting in the banjo.. Don't know if you have already but I'd flush the coolant as well. I'd also want to open middle gear case and look for bluing,, while there I'd check the key for the oil pump drive, likely don't need to explain how or why. Now there a note on 3-35 that the plate spines can cause erratic operation... And while you have the Boss in your hand 3-34 shows the tolerances. Ask you this, would you hazard to guess the engine temp is much above 172* when the failure happens? Does she tick more or knock low even slightly? Thinking here some might choose a higher weight and that's fine but from a wear point not a heating problem like we're thinking cause that will hold more gigajoules longer; just my opinion. Keep us in the loop Patch

I feel your pain at this altitude;) I'm going to go through my playing cards and see what I can come up with, I'll post later. Chin up

As for the oil in the air box true it may have something to do with oil level but it shouldn't. Yes it will gather on any bike toward the side stand side of the box. More likely if it is excessive then it is blow-by related and that too could be your miss as well.. I'm in Calgary and willing to lend a hand, I can sync and check pressure flows in one step as well, likely tho I'd want to check compression tho, kind of mean that way; Patch

I went thru the clutch diagram, thinking about what you said (it happening on the stand with fans on...) I got to thinking bearing or oil drive? If you are 99% sure its not the disks, slave, master, lines, and fluid then you are going to need to open her up. For the fun and cause we know you have nothing else to do... check the oil pressure, eh.

In my mind it is heat related. The switch is a side effect, its a cylindrical closed container with contact point and a spring loaded rod; its not hard to imagine it expanding under an overheating. Look it is clutch related, if its not caused by the properties of the fluid then what? Ask the question what can render the fluid useless and you're back to a heat issue in this case. You are sure about the vent, hoses, slave and master so, what's left and what can cause that much heat? If the vent was blocked then the hydraulics would be in a equal pressure environment reservoir side of plunger, and as you know that renders the action ineffective (it can't push). Some years back on a mountain ride thru and after changing fluids I lost clutch action, in that case it was the vent, a simple fix. I could describe all you mention but for the position switch, so why or what can make that switch behave that way hot? It has to be overheating

Anybody ever mention you are a stubborn old saddle tramp? You know you're describing a heat issue, and we know you know hydraulics so; have a double shot of expresso then unhitch the horse trailer from the bike and get down there and find what is causing it. Your cap vent is clean right?

Sounds to me like your pilot jets are plugged solid. Patch

Yep, your clutch is likely slipping. I would hazard that the heat is adding or contributing to the ghosts you mentioned.. If it were me, I'd strip the clutch down. I take it you haven't added anti frictions? I've got a few days coming to me so drive up and lets see what you drive back;) Patch

Not sure if you're looking for help or suggestions? But the standard compression is only 142 lbs and the max is 156.. So, shouldn't be a hard engine to spin given a good battery. Now tho you will be subject to preignition as well other destructive forces such as suddenly reversing crank rotation; best tend to it before it starts bending rods and crashing journals. Don't know the mileage nor how much you value the bike, the ball is in your court. I would guess there may also be a problem with the PCV, and should the rings be worn (likely) then the blow-by will cause excessive carbon buildup in the oil then on the valve seats thru the crankcase vent which will deform the ground/cut seat angles and surfaces; also wears the stems, scores the cylinders, journals, common oil flowing across the gearbox ... so... A tear down with that much carbon really is the best way forward.. Patch

Listen,,,,,,,,,,,,, you are fortunate that the intake valve seats are leaking the pressure! You are way over the max compression limit! The bike has been run way too rich, for way too long! What is the mileage? You have too risk decarbonising, I haven't covered it but I can it in my fogging post but unless you want to pull the heads we can try it chemically. Patch

Good info Tennessee. My view was not that one pad has more wear, its that the pads may be wearing at an angle, in other words not flat. Patch