Hi everyone, A buddy of mine just recently gave me a 87 CH150 with only 577 miles on the clock. It has sat outside in the yard (uncovered) of the original owner for about 13yrs. My buddy is a computer tech and rides a 86 CH150D and after working on the guy's computer, he offered the owner his work for free if he gave him his neglected CH150. The owner agreed and they traded the CH150 for his work rendered. Orginally, my buddy was going to keep both the scooters but since he knew that I was very interested in a scooter and I was the one that got him the lead to his CH150D, he offered the scooter to me. When I got the CH150 from him, it did not want to start. Here are some of the sequence of events that took place to get it running: - Flushed out radiator fluid, changed oil and flushed out gas tank. Filled gas with Chevron Premium and some B12 mix, radiator with just water and oil with Mobil 1 synthetic. - Installed a new battery, but nothing, except that the temp guage will rise and stay on the top - Tested all the electricals and after removing all the panels and plastics from the scooter, we found that the battery ground cable was loose and the contact point was corroded. Sanded down the contact points and tighten the bolt and the scooter fired right up (pretty amazing for a scooter that sat outside for 13yrs). - Filled tire pressure to spec and twisted the throttle with the center stand down. The tires wabbled a bit at high rotation but nothing too serious. The rubber is extremely hard, but still plenty of thread left. - Test rode the scooter around the block. It got up to 45mph but nothing more. It was kinda late already so I parked and decided to do more after I register the bike with the DMV. - Got the scooter registered (pain the butt since it was not registered for the last 13yrs, but got it done). Re-upholstered the seat and now for the test run. - After a few hard, full throttle runs, it seemed to get up to around 52mph. I decided to ride down to my buddy's house (20 miles) and during the trip, the bike hit around 58mph on flat land. It felt stable and strong. This was during the day when the temperature was around low to mid 80s. - Parked the scooter at buddy's house and decided to leave around 10pm. The temperature was probably low 50s and the scooter wouldn't run past 45mph at full throttle. I also noticed that during hard off the line acceleration, the drive belt seems to skip a notch or two before grabbing hold. - Next day morning, the bike was acting the same way so I decided to buy some carb/choke cleaner and sprayed the intake while running the bike at high rpms. I parked it outside in the sun for a couple of hrs and then took it to another friend's house. The bike ran great and hit 58mph again and I figured the whole problem was fixed. - On the way back at night, it ran great again, but I got stuck at a left light for quite a long time, since the sensor did not detect me and I had to sit through a couple of signal changes before another car got behind me to trigger the left light. I took off and immediately felt that the scooter was running poor again. I talked to a few friends and they all have different suggestions. Here are some of them: - Poor ground (I don't think this is the case and just for the sake of argument, I connected another ground wire from the battery to the engine block - this did not solve the problem). - Carbuerator needs cleaning (I don't think this is the case either, since the bike started fine, idles fines and runs with no surging). When it runs poor and does not exceed 45mph, it still runs smooth. It just feels weak and cannot accelerate as strong and can't pass 45mph. - Fuel filter needs cleaning or changing (this might be the case but it does not explain the inconsistency in performance). I will do this anyways since it is a good maintenance item. - Air filter needs cleaning or changing (same thought as fuel filter). This is my own diagnosis: - I think the drive belt is old, hard and needs replacing. The bike seems to run well in warmer weather and I think that is because the rubber tends to get softer when it is warn. When it is colder, I think the belt is not moving/triggering the pulley accordingly and thus the inconsistency in performance. I am no expert, but this is my best guess for the moment. Some of you might think that I should just open up the bike and look at all these items I that I have mentioned. However, I am currently on a business trip and will not return till Feb of next year. I am just trying to drill down the cause and buy the necessary items upfront so I can start the repair and maintenance immediately when I return. If anyone of your experts out there can shed some light on this, it'll be much appreciated. Thank you.