Had it was not for a couple of queries send from Aditya, lazy me would have never written this post. I would like to add a disclaimer here that, what I’m writing is just based on my personal experiences; it might not be the ultimate solution/guide for the problems.
Planning for Sikkim in November on my Apache 150 (2006 model). Two queries
Query: 1. Any adjustment to Carburetor required at the altitude if yes, what? (Checked with bike guru, he redirected to you!!)
As I have never been to Sikkim, I can’t say anything specific to Sikkim but based on my personal experience I had during my 4 visits to Ladakh and a single visit to Spiti Valley (both places have enough high altitude sections). I’ll say don’t touch the carburetor. I had gone to Ladakh and Spiti on my Fiero (Apache 150 engine and carburetor is very similar to that of Fiero) and I have never touched the carburetor or the air filter during the ride. The bike climbed up anything and everything that came in its way, including the Tanglang La during a snow fall, with a pillion and luggage of two people on board.
If I was in your position, I will just get the bike serviced before the ride and go on the ride.
Just in case you do decide to play with the carburetor, I’ll suggest you carry a main jet that is one size smaller than what you have in your bike (in case you want one on a loan, let me know). Switch the main jet, to smaller one, once you are at a high altitude, this will make the bike run lean (bike will be running richer as going higher in altitude, the air gets thinner and hence air/fuel ratio goes on richer side), remember to switch back to stock jet as you start to scale down the altitude, else it (running lean in lower altitudes) could damage your engine.
Query: 2. Changing both tyre and tube, the garage guy advised to go for Tubeless, not sure if this will create a problem, any guidance on this?
I’m a big fan of tubeless tyres. So, if you are getting tubeless tyres for your bike, I’ll say get them. But with tubeless tyres there is one big disadvantage, if during the ride due to some bad roads the rim gets damaged; it will result in air leak. As a result tubeless tyre will be rendered useless. So, to deal with such scenarios, do carry spare tubes with you, so that you can fit the tubeless tyre with the tube and run it like a normal tube type tyre.
In case you don’t want to fit the tubeless tyre and are worried about the tube type tyre getting punctured. During my last Ladakh ride, I used a puncture sealant called “Slime”. You can fill this liquid inside your tube and in case of a puncture caused by a object up to a specific size; the sealant will fix the puncture on its own. I did have an firsthand experience of seeing this solution at work. While coming back from my Ladakh ride, my Fiero’s rear tyre had a nail in it. I just removed the nail, in a couple of seconds the puncture was sealed by this solution and I was able to ride the bike, all the way from Sonmarg to Delhi without having to do anything else.