1. My Bike has a Stumble around 4000 rpm, how can I get rid of it ?
This is a fuel related problem. look at the following components to solve the problem,
Carburetors: Completely cleaned of any dirt internally, correct jetting, fully syncronised,
Adjust the accelerator pump to spray properly.
airbox: make sure the flapper is operational and functioning properly.
vacuum hoses: tight, no leaks anywhere and that includes the yics chamber.
My Bike isn't charging, battery keeps going dead etc.
generally caused by a malfunctioning stator or voltage regulator.
the electrex troubleshooting chart @ www.electrexusa.com
charged battery 12.6 volts with the key off.
13.2 minimum over 2000 rpm.
see the links pages.
Starter problems, won't crank over or slow cranking. -see starter clutch faq.
things to check:
charged battery - 12.6 volts with the key off
cables and electrical connectors
Solenoid connections and operation.
possibly full of oil, leaky starter seal)
See the starter repair page
Leaky Fuel tank, petcock problems
rusty tank repair using por-15
rebuild kit for 82's and 83's they are different.
brake problems, spongy front brake, not enough stopping power. adding better performance
Brake Hydraulics are bad, contaminated brake fluid, worn seals.
the master cylinder
the pads, resurface the rotor(s)
brake fluid every season.
braided stainless steel lines.
install ferodo brake pads
exhaust problems, rusted exhaust, where can I find a replacement ?
The stock system is not available from Yamaha, there are several options for repair\replacement.
buld your own from scratch.
install a MAC system
a used one through ebay or the junkyard.
just the muffler(s) with an aftermarket such as supertrapp or ????
a new predator exhaust -see the links pages
Ignition problem, no start\spark, tci issues.
Things to check are the ignition switch and fuses. The starter cutout relay, the connections to the tci unit and lastly the unit itself.
they are somewhat repairable, it is difficult and should be avoided unless you have experience working with solid state circut boards.
of the typical failures are the unit getting wet inside or one of the diodes failing.
diodes can be had at radio shack for about 3 or 4 dollars.
the wetness problem, wd40 sprayed into the unit and allowed to dry out for a day or so can sometimes bring it back.
Starter clutch issues, knocking in the engine at low speed, start cranks but engine not turning over.
worn or broken starter clutch.
how to repair it, see the technical pages
bolts, use locktite, peening bolt ends over.
Cooling system problems, runs hot, overheats in traffic.
Thing to check; Thermostat, you can pick up a cheap replacement at any autoparts store, just ask for a 1986 chevy nova unit. make sure the vent is up when you install it. The cooling system needs to be bled, there is a bleeder fitting underneath the tank on an aluminum casting. I typically fill my bike up there with a small funnel and a bit of patience.
The fan is not coming on, check the harness to the temperature switch, with the key on, test the circut by grounding the blue wire at the sensor. The fan should start running at that point. you've now verified the fan operation as well as the relay. one way to test the sensor is to place it in a pot of boiling water and using an ohmmeter check the resistance across the contacts, it should be open until it gets up to 180f or so and then have continuity across the contacts when hot.
a possible plugged radiator.