from the begining of this week the sun was shining,T° is 97°F

The engine is so hot, as soon as i stop the fan is running
The T° gauge show exact middle, even on the motorway at 4 or 5 rpm

Is it usual ?

The engine and the exhaust give a lot of "hard" noise wich disappear when the T° decrease

The oil is Motul 5100 10w40

is it the good one ? the best one ?

The clutch become little bit harder with such T°

So the main question : is this bike an hot one ? hard to get colder, vapor lock on carburetors when refueling

So your opinions, advices, comments ?

(just a detail, the previous owner has make some holes in the muffler ( just one , just in the middle D=15mm (0.6inches)

may be the engine work a little bit poor ? it's popping very hard (more a BANG than a pop)

what can I do ?

Is it poping on deceleration or sustained rpms? If decel, here is an excerpt from the Vulcan Verses:
The sound (popping upon deceleration) is created in the exhaust pipes because of Kawi's EPA emissions design. Kawi designed the system to add cooler fresh/filtered air into the exhaust in order to create a second burning of wasted or unused mixture that may not have completely combusted during the times of closed throttle/decels. The poppings you hear are the secondary combustions in the exhaust sounding out

Couple things. First, everyone else is right about the air mix screws. Turn them all the way in (Clockwise, using that very small screwdriver) and then turn them out about 2 turns. If you experience popping, turn them out another 1/4 turn. If that doesn't work, try another 1/4 turn. Keep doing that, but don't go more than 3 1/2 turns total.

Third, you might want to consider coasters or marbling to cut off the air to those reed valves if you haven't already done so. Some combination of these things should eliminate the popping, or at least greatly reduce it. Good luck, and keep us posted on your progress. I'm curious to learn what works for you. Jim "Pick" Foster Dixon, IL

I just finally found marbles yesterday and put them in and it stopped the popping completely on mine. The marbles go into the hoses that are clamped onto the ports on the reed valves on each valve cover. You should be able to get to both of these just using your fingers to remove the clamp and stick the marble in the hose, push it in far enough to be able to put the hose back on the port and clamp it back on. By the way, I'm in Texas and it's been right close to 100 degrees every day this week. Hope this helps!

If your tranny is shifting harder when it's hot I think your oil is getting cooked and oxidizing, try to find some full syn oils and see if that helps.

Seems to be more explosions than popping, but I will try with the air screws.
Just a comment, when I close the holes the previous owner has done in the mufflers it's just popping no BANG, so I will look how to close them.

On the idle T°, are yours the same ?
Is it a bike which is heating a lot ?

My bike runs in the middle of the temp gauge, 12 oclock if you will, when it's really hot out and especially if I'm going through town, stops and starts. Hottest it's ever gotten is just past middle, still covering the writing there in the middle of the gauge.