I feel your pain RX1MPete. It's always tough to say goodbye to an old friend who's treated you well. Do you still have the MSRX, or are you entirely "smokeless" now?
After I got rid of my '00 SRX and switched to the 4-strokes a few years ago, I was still pining for the feel and sound of the SRX. I was lucky enough to find a '02 SRX that was still in the crate. I picked that one up as a spare sled, and ever since have been chipping away at it to bring it up to speed.
I've currently been running a Mono skid with a Ohlins EC shock in the sled that's been extended to a 146". It's got electric start/reverse, and a wide front end with Fox Floats. Put a taller seat and risers on it and some other things, and now it keeps right up with the 4-strokes in all conditions.
