KTMphil
Senior member
Thailand - Tenere Exhaust Modification - Day 184 (16,702 miles)
This is an report from John and Jane riding around the world on an exhaust heat problem they had and had rectified in Chiangmai, they have a great blog:
http://testrunjmacandjane.blogspot.com
READ ON:
Some will remember the issues that Jane and I have been having with the rear tyre on the Tenere, which put simply is the tyre is over heating and failing prematurely. We fitted another new rear tyre (the third in only 16,500 miles)when we got to Sydney. This was not because the tyre was worn out but because there was significant cracks appearing in the tyre tread and one could see that the tyre was prematurely ageing. The cracks were not too dissimilar to what you would get when the tyre is regularly over inflated. After time we did consider that we may be over inflating the tyre because of the load we are carrying on the bike, but we had been managing the tyre pressures very accurately because we suspected this first. However, when we met up with other riders in Chiang Mai who were doing the same kind of journey, two up, on the same tyre size and rating with no trouble something didn't seem right. Another factor that I have always considered, but dismissed because I couldn't believe Yamaha would make this kind of error, was the Yamaha Akrapovic exhaust fitted to our Tenere could be heating the rear tyre.
In short the Akrapovic exhaust system was fitted to remove the catalytic converter so that we could use low grade fuel. The design of the Akro exhaust means that there has to be a balance pipe across the rear of the engine, just in front of the rear tyre, to feed the two rear silencers. (Aha I hear!) However, in my defence, everyone I spoke with at the dealers and on the road up to Chiang Mai like me couldn't believe Yamaha would make such an error and also couldn't see how it was possible for the balance pipe to heat up the rear tyre.
Anyway, in Chiang Mai after an aborted trip into Laos because the third tyre was failing prematurely for the same reasons as before, we decided to test the exhaust theory. We returned to a Hotel in Chiang Mai called Riders Corner (great place to stay, details below) the owner Phil is a very helpful man and was able to put us in contact with other people and trades in Chiang Mai who could help us with our problem. Also, after discussing the problem with Colin Saunders of Saunders Motorcycles in the UK, where I got the Akro exhaust, it was becoming clear that the the design was probably the real issue and Colin helped confirm what we should do to try to eliminate the problem. Incidentally, Colin also confirmed that the Akro pipes had two Cat's in the system even though they were advertised and reported in TBM as not having them? This would increase the heat around the rear of the pipes.
The solution was to remove the Cat's to increase the gas flow (to reduce the heat) and have a heat shield manufactured to deflect the heat from the balance pipe away from the rear tyre. Phil and a friend of his called Rob put us in contact with a welder fabricator called 'DKT' in Chiang Mai who could carryout the fab work for us in a design and build kind of approach. So this we did.
This is the Tenere having the exhaust removed.
These are the two welders who worked on our exhaust for six hours, the welder was a very skilled Tig welder and fabricator but he spoke very little English and my Thai is useless outside of a restaurant or bar so we used a series of sketches, gestures and physical demonstrations to get the design and requirements across. The owner however speaks great English but he is not around all of the time.
This the finished job with the two shiny bits of tube on the LH and RH side of the pipe replacing the two Cat's and the shiny tube in the middle at the back of the picture being the new heat shield. The whole job cost us 1400 Baht (£28). You can see from this picture how close the balance pipe is to the rear tyre.
DKT welder fabricators (GPS coordinates ads the place is almost impossible to find otherwise)
N 18.76714
E 098.98189
Tel: 053-202269-70
This is an report from John and Jane riding around the world on an exhaust heat problem they had and had rectified in Chiangmai, they have a great blog:
http://testrunjmacandjane.blogspot.com
READ ON:
Some will remember the issues that Jane and I have been having with the rear tyre on the Tenere, which put simply is the tyre is over heating and failing prematurely. We fitted another new rear tyre (the third in only 16,500 miles)when we got to Sydney. This was not because the tyre was worn out but because there was significant cracks appearing in the tyre tread and one could see that the tyre was prematurely ageing. The cracks were not too dissimilar to what you would get when the tyre is regularly over inflated. After time we did consider that we may be over inflating the tyre because of the load we are carrying on the bike, but we had been managing the tyre pressures very accurately because we suspected this first. However, when we met up with other riders in Chiang Mai who were doing the same kind of journey, two up, on the same tyre size and rating with no trouble something didn't seem right. Another factor that I have always considered, but dismissed because I couldn't believe Yamaha would make this kind of error, was the Yamaha Akrapovic exhaust fitted to our Tenere could be heating the rear tyre.
In short the Akrapovic exhaust system was fitted to remove the catalytic converter so that we could use low grade fuel. The design of the Akro exhaust means that there has to be a balance pipe across the rear of the engine, just in front of the rear tyre, to feed the two rear silencers. (Aha I hear!) However, in my defence, everyone I spoke with at the dealers and on the road up to Chiang Mai like me couldn't believe Yamaha would make such an error and also couldn't see how it was possible for the balance pipe to heat up the rear tyre.
Anyway, in Chiang Mai after an aborted trip into Laos because the third tyre was failing prematurely for the same reasons as before, we decided to test the exhaust theory. We returned to a Hotel in Chiang Mai called Riders Corner (great place to stay, details below) the owner Phil is a very helpful man and was able to put us in contact with other people and trades in Chiang Mai who could help us with our problem. Also, after discussing the problem with Colin Saunders of Saunders Motorcycles in the UK, where I got the Akro exhaust, it was becoming clear that the the design was probably the real issue and Colin helped confirm what we should do to try to eliminate the problem. Incidentally, Colin also confirmed that the Akro pipes had two Cat's in the system even though they were advertised and reported in TBM as not having them? This would increase the heat around the rear of the pipes.
The solution was to remove the Cat's to increase the gas flow (to reduce the heat) and have a heat shield manufactured to deflect the heat from the balance pipe away from the rear tyre. Phil and a friend of his called Rob put us in contact with a welder fabricator called 'DKT' in Chiang Mai who could carryout the fab work for us in a design and build kind of approach. So this we did.
This is the Tenere having the exhaust removed.
These are the two welders who worked on our exhaust for six hours, the welder was a very skilled Tig welder and fabricator but he spoke very little English and my Thai is useless outside of a restaurant or bar so we used a series of sketches, gestures and physical demonstrations to get the design and requirements across. The owner however speaks great English but he is not around all of the time.
This the finished job with the two shiny bits of tube on the LH and RH side of the pipe replacing the two Cat's and the shiny tube in the middle at the back of the picture being the new heat shield. The whole job cost us 1400 Baht (£28). You can see from this picture how close the balance pipe is to the rear tyre.
DKT welder fabricators (GPS coordinates ads the place is almost impossible to find otherwise)
N 18.76714
E 098.98189
Tel: 053-202269-70
