Simplicty Soveriegn 7100. I have what appears to be a power issue. When mower deck is engaged and going up hill the tractor boggs down. Simplicity Sovereign Lawn and Garden Tractor tractor Mfg.#1692943. It is a 1997 model The deck is a 48" cut and the model # is 1691219 This tractor has been re-powered with a top of the line Kohler CH25S The engine spec# is 68544 Disp 25? Serial Engine#2633815377 I have it in the shop since November and stopped by last week was told that it might be a control unit. Because the engine was running on one cylinder. My question, is it worth the investment? My concern, Considering there may be more wrong with cylinder. $200 controller plus engine removal.