Motorcycle Repair: fuel problems???, honda rebel 450, cam bearings

Question
Hey Chris, my names Charles and I just purchased a 1987 Honda Rebel 450 with 9,000 miles on it.  Yesterday while riding home in OverDrive going about 85 mph I noticed my bike start to stutter.  I pulled over and let it cool off, and continued to ride the last couple of miles home.  This morning the same thing happened about a mile from my house.  After about an hour of unsuccessfully trying to get the bike to stay idling I finally limped it home stuttering.  It definetly seems to be a fuel problem, because the bike runs fine while theres fuel in the carb and float.  My pop says it's the fuel filter, probably got clogged with old gas or something.  If you could please e-mail me back as soon as possible it would be greatly appreciated, thank you.

Answer
Sounds like a good bike, but you need to check things over before blasting down the road at that speed....

Oil level! If yours is low and you are running it hard, it will seize the pistons, cam bearings, etc...

Check fuel cap vent or tank venting system:
http://houseofmotorcycles.bikebandit.com/partsbandit/oem_schematic_view.asp?sche...

The petcock has a fuel bowl on the bottom with a screen up inside that can be inspected and cleaned. The petcock is also a vacuum controlled unit, that has a diaphragm to shut off the fuel flow when the engine is not running. Diaphragm failures are not uncommon with a bike that is this old.

The low miles indicate that the bike has been sitting a lot and the fuel tank should probably be drained, checked for rust, water, dirt, etc. If it is contaminated, the petcock will get full of dirt quickly. It is also likely that water, dirt, debris are down in the float bowls, so drain them out with the drain screws. The bike will be hard to start afterwards as the petcock only opens when the engine is running, so it will crank for a long time while little pulses allow fuel in a little at a time.

You may have stuff floating up into the main and idle jets, so a carb clean is a good idea. Check the vacuum lines to the petcock, too, as a damaged or loose line will cause the same problems as a bad diaphragm.

Bill Silver