I installed the ARE heat shield and put two layers of ThermoTec self adhesive heat shield on the back side of it before installation. That did help a lot, but I still seem to be getting hesitation to start when the engine is hot, and a bit of rough running while at stop lights when it is really hot out. I have an override switch on my 14 inch electric fan and I use that all the time at stop lights even though when I stop the gauge is not reading over normal. As I set at the stop light in 95/100 degree heat, the temperature gauge rises quite rapidly even with the fan running and takes quite a while to go back down after moving, if it even does go down before the next stoplight. (I seem to hit them all on red cycle). That is when it starts to run rough. If I can keep moving even when the temperature outside is hot, the air dam I fabricated keeps the temperature gauge at normal without the electric fan on, and it runs smooth. So that is why I was thinking it might be fuel line heat since the fuel line runs right along side the engine and the ARE heat shield does not protect the fuel line when it comes over the manifold going to the fuel bowls. (BTW, I put a small cable tie around the fuel line and vacuum line and the bracket coming off the thermostat housing to ensure they don't fall down into the water pump pulley).
Also on 6-Pack they were talking about gas line heat shields to help with vapor lock and percolation. I have not had a problem on my TR250, but in the back of my mind I was thinking of putting fuel line heat shield on it as well just to be sure.
Regards,
Bob