I have what I hope is not a serious problem. I just bought a 1995 Airstream Land Yacht 33 ft with a Chevy 454 engine. During the test drive the temp gage went right to the red zone and pegged right after being started. After a 10 min drive we used a handheld laser temp gage and read the temp as 205 deg at the thermostat and 185 on the radiator. Engine did not seem hot, so we assumed a faulty gage. The 10 minute test drive did great & I purchased the unit "as-is". The unit cranked right up to drive home, however I noticed much reduced power when attempting to accelerate. About 2 miles later, it started to run rough, and my top speed became 35 mph. I had to hold brake & a little gas to keep it from dying at intersections, and it would knock & backfire if I attempted to give it too much gas to slowly make it back up to 35mph. The unit had been on a consignment lot for the last year, however they stated it did get driven around the lot every few weeks. There is fresh gas in the tank, and the generator runs strong and smooth. I'm sorry for the long post, but I am at a loss for explaining why a test drive would go so well, and the trip home 30 minutes after signing the paperwork seemed like a different engine. I limped it back to the dealer & left it in the lot since I couldn't get it home. HELP !