I bought this sled for 100 bucks and it runs pretty well, but as the purchase price indicates, most parts on it need replacement/overhauling. In the spring I intend to replace the one (?) shock under the tunnel. In the meantime, is there any adjustment I can make to the suspension? When I sit on the sled it tends to sink to what I think is a bottom-out point and I wondered if there were anything I could do for now.