Wilsons Sandbox

TAM posted-- Problem with the bike is, it does not have any power over 3k rpm, and WOT it will not go over 60mph or much over 5k rpm (down hill with a tailwind) The bike runs ok at lower speeds and pulls ok until you get the revs close to 4k, then it just looses its balls. Tam REPLY-- Tam, It is not clear if this was a sudden-onset problem or you got the bike in this condition.... You have received many valid suggestions-- especially the valves and aircleaner; I especially like the aircleaner suggestion as an easy check. and here is one more suggestions based on my bike acting the same way as yours = sudden onset problem; it swallowed a bug which parked itself on the main jet! It believe it entered through the carb vent system. The bike started fine, but would barely pull 4-5k rpm's, or <50 mph. What an unpleasant feeling to be on a backroad after dark, 15 miles from home barely making 45mph. In the process of checking several easy things, After the airfilter, I would add: 1. check the carb vent hose and make sure it is not plugged or restricted in any way. sooooo.... Before you remove the fuel bowl and check the mainjet, 2. Let's Drain/Purge the fuel bowl shut off the fuel, drain the fuel bowl from the right side, hopefully catching the drained gas and sediment on a clean white cloth. Water will appear to be a momentary 'bubble' on the cloth. Sediment will appear to be 'dirt'. smile. While you got the fuel drain screw removed, turn the petcock ON. If it is a properly operating OEM, petcock, no fuel should come out the drain hole at this time. Now, Crank the bike and see if the bike has a healthy flow of fuel out the pet cock. If it is a properly operating OEM petcock, fuel should pulse out the hole everytime the bike makes compression/vaccum. Note to self: DO NOT STARE AT THE DRAIN HOLE--YOU MIGHT/WILL GET AN EYEFULL. Try to catch the excess on the white cloth for water and sediment. About 3 seconds should be enough or until the waater and dirt no longer appear. You might get lucky and wash off anything that might be on the main jet (didn't work for me either. grin.) Replace the screw, mop up excess gas, start and ride the bike and see it it runs better. No? then I suggest 3. you should check the mainjet. Loosen the two clamps that hold the carb in their 'boots'. You will have to rotate the carb to remove the fuel bowl on the right side of the bike. (detatch the choke cable at the handle bar, remove the throttle cables at the carb as necessary. It is ABSOLUTELY NECESSARY that the choke is loose or you will break the fitment on the right side where the cable enters the enrichment chamber.) Remove and inspect the main jet, clean as necessary. Reverse the teardown sequence. These are quick and easy checks before you have to take the gas tank off and check the valves and valve clnc etc. You might get lucky--my bug-wing had cork-screwed itself into the main jet and the only way it was coming out was by force. Don't underestimate the difficulty a dirty or overserviced airfilter can cause as well. Big Dog Sampson told of his riding partner who was riding #3 in the South half of the the GDR--his bike would barely make power. When they opened the airbox, they had to spoon out the dirt to get to the aircleaner. True story. Please let us know what you find out. revmaaatin.