The rotor puller for the KLR 650 rotor is a M22X1.5 thread (22mm dia X 1.5mm height). You can get M22X1.5 bolts for little money from engineering shops worldwide. 50mm thread length and standard hexagonal head is fine. They usually come in grade 10.9 at least, more often 12.9 which means they are adequate in strength for the task of pulling the rotor. The rotor sits extremely tight if it was never removed before. Sometimes it's a good idea to plane the front face of the bolt as it's usually a bit hollow and skew from manufactury. As far as I know and have seen on my KLR's the rotor is not secured with loctite in the factory. It's just very tight. I don't use heat to loosen the rotor as it works without and I am a bit worried about affecting thermally threated parts too much. I also don't use big hammers.

The same rotor puller also fits a huge range of other Jap. bikes generators and is something of a Japanese standard. Means: If you can locate a shop which works on Jap. bikes they will most probably have one.

To hold the rotor you should get yourself a good quality CrV spanner, I think it's a 32mm (?). Don't buy a cheapo as you might hurt yourself. I used a Stahlville CrV "Alloy" open box. (one open end one ring) Gedore is fine too.
Clamp the open spanner end in a solid vice.
Heat it with an acetylene welding torch just where the shaft begins until red hot. Heat it quickly or you will not be able to bend a small radius. Bend 90°.
Let it cool slowly WITHOUT USING OIL OR WATER.
Heat a second time further up the shaft to bend it around the rotor. This time you have to bend some 100 to 105° to make sure the end of the spanner sits under / above the footrest in a plane with the other end engaged with the rotor. Otherwise the spanner will slip under load.

Do not cut and weld spanners, do not cool down red hot spanners rapidly, do not heat and bend cheap shit spanners!
In each case the spanner will get brittle and break under load without warning. This will not have consequences for the bike (besides that the blimmin' rotor is still fuss) but might be painful to you / your shins / calfs / hands...
The easiest way to finally remove the rotor is a solid impact driver (ideally 3/4" drive) as you can find them in truck workshops. Do not use 1/2" socket and lever as the lever will bend (= angry owner) or the drive will snap (= "ouchdammit" and angry owner).

I never loctited either rotor onto the shaft cone or rotor bolt into the shaft. Just tightened to 140 Nm and never had anything falling apart. I also never used new rotor bolt as some original Kawa manuals require.

I am very surprised to hear of the cam chain tensioner failing. They were used on a wide variety of Kawasaki bikes for more than 20 years and never known to give trouble. Bad luck.

A bike with a broken doohickey can go for quite a while although it causes the balancer chain to wear quickly. It also causes wear and damage to the sliders of the balancer chain. It should get fixed as soon as possible.