I have a spike on my injected TC it made heaps of differance to performance...
Rain is it ever going to stop, I use motorcross sprayon air filter oil, been caught a few times in heavy rain doesnt seem to affect it...
Check out the Big Air site for a new carby...

Can't go wrong with the mukuni.As for the duel wimmer even better.Rain no problem you can get a rain cover,the water won't cause any problems.Should all bolt on.

Just put on a weather proof sock , Job done