Well here is my write-up today on advrider..
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Well I done it....
Fitted the 477cc big bore kit from Himalayan-Tools, a TEC cam and a 16 tooth front sprocket and my verdict is...
This is how RE should have set up the Himalayan. It runs smoother which might be the lighter forged piston and the gearing just seems a bit better in the stop-start traffic on my commute to work today. The sprocket brought the rev's down by about 250rpm which puts the engine in that sweet spot of 4800 to 5000rpm maximum torque for our highway speed limit. Roll-on at that speed in top gear is instantaneous and strong.
My Himma is a carby model which makes the change easy. I was running the standard carb config of 125 main and 15 pilot/idle jet but increased the pilot jet to a 17.5. I had a tank of 91 RON petrol and did get pinging because of the higher compression ratio. Squeezing 2 liters of 98 RON improved it. After another run I put another 3 liters of 98 RON in and the pinging was gone. I am running it on 95RON now and there is no pinging, even at high loads. Now for a long run thru the Southern Alps to see how it affected the fuel consumption. All in all not the most difficult job to do and well worth the effort and investment.
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I kept it low key on purpose not to upset folks there. Hopefully it might stir some interest and business for you. I would say the 2.5 hour claim for the time to fit it might be in a workshop. It took me about 6 hours on my own working at a steady pace with a couple of short coffee breaks and lunch. I did not replace the timing chain as it had no wear and was as stiff as to remove from the cam gear. I have only run synthetic oil in mine and change every 5000km with a new filter every 10 000kms.
Here is a good tip for handling that pesky timing chain and keeping the tension on it. That untying and retying of the rag on that chain in the video just seemed so clumbersome. I found a small bungee cord with a hook that could go through the hole in the head and block and it worked a treat. Hook it on the chain and on the bike frame to keep tension. It can stretch then when you remove the head and the barrel. Bonus is too the if the engine move then you can turn the engine and the chain will just turn & slip on the bungee's hook without loosing tension.
"
Well I done it....
Fitted the 477cc big bore kit from Himalayan-Tools, a TEC cam and a 16 tooth front sprocket and my verdict is...
This is how RE should have set up the Himalayan. It runs smoother which might be the lighter forged piston and the gearing just seems a bit better in the stop-start traffic on my commute to work today. The sprocket brought the rev's down by about 250rpm which puts the engine in that sweet spot of 4800 to 5000rpm maximum torque for our highway speed limit. Roll-on at that speed in top gear is instantaneous and strong.
My Himma is a carby model which makes the change easy. I was running the standard carb config of 125 main and 15 pilot/idle jet but increased the pilot jet to a 17.5. I had a tank of 91 RON petrol and did get pinging because of the higher compression ratio. Squeezing 2 liters of 98 RON improved it. After another run I put another 3 liters of 98 RON in and the pinging was gone. I am running it on 95RON now and there is no pinging, even at high loads. Now for a long run thru the Southern Alps to see how it affected the fuel consumption. All in all not the most difficult job to do and well worth the effort and investment.
"
I kept it low key on purpose not to upset folks there. Hopefully it might stir some interest and business for you. I would say the 2.5 hour claim for the time to fit it might be in a workshop. It took me about 6 hours on my own working at a steady pace with a couple of short coffee breaks and lunch. I did not replace the timing chain as it had no wear and was as stiff as to remove from the cam gear. I have only run synthetic oil in mine and change every 5000km with a new filter every 10 000kms.
Here is a good tip for handling that pesky timing chain and keeping the tension on it. That untying and retying of the rag on that chain in the video just seemed so clumbersome. I found a small bungee cord with a hook that could go through the hole in the head and block and it worked a treat. Hook it on the chain and on the bike frame to keep tension. It can stretch then when you remove the head and the barrel. Bonus is too the if the engine move then you can turn the engine and the chain will just turn & slip on the bungee's hook without loosing tension.
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