Any ideas why my 1987 Warrior would basically run into a rev limiter at 6500rpm? I tried a new spark plug, no change. I tried different carb setting and still no change. The behavior leads me to believe its an ignition problem. Any idea where to start looking?

Aaron

 

I had the same problem on my 89 warrior, I had to redo the entire electrical system, I guess its the nature of the beast... good luck fixing, hope you dont have to rewire it.

 

How did you redo the electrical system? Did you buy a new harness and just replace it or did you repair the old one? What other components did you replace?

Aaron

 

Anyone?

Aaron

 

What I would try 1st is to locate the problem. 1st put a test light at the small wire connection to the ignition coil. (called the coil primary side). Should make the test light flash. Cranking the bike before it starts will make the light flash at a slower rate. When running it should stay constant. If after 6900 rpm (your cut out rpm you are experiencing) the light does stay on then iy must mean your ignition coil is bad and can't handle the higher demand. If there is a signal going to the coil primary it should be sending a spark to the spark plug. Now if the light goes out gets spiradic at 6900 rpm then apparently the signal is being lost to the coil primary. This wire will back track to the CDI unit. Test for a good signal at the CDI. If it is good there then it is that wire and you have a problem in the harness in between the two components. there are only two connectors. One at the CDI and the connection at the coil. Simple design and only about 3 feet of wire. If the signal is also bad at the CDI then check to see if the pulse coil is putting out a voltage. (2 to 6 volts). You need either a multimeter using a needle (Not a digital meter). or ask your Yamaha dealer to check with their meter called the Ignition Mate. ALso check the output of the stator windings. (3 white wires). Should be at least 18 volts across any two of the wires. The pulse wires and stator wires go directly to the CDI unit as well. If you do have a good signal the the CDI from the stator and pulse coil but no signal on the wire from the CDI leading to the ignition coil then you have abad CDI. THink of hte CDI asa relay or an electrically operated switch. It gets voltage or power from the battery and the stator. It switches the power to the ignition coil when the pulse coil sends a signal to the CDI. So there should be signals at the input to the CDI as well as the output of it. If signal comes in but none comes out it is bad. !st be sure your ignition coil is good and also your battery. Most likely and most common problems.

 

Hello again. I did overlook two other possibilities. Switches. The kill switch ont he handlebar and the key switch. If they are starting to go bad they can arc or drop the required voltage at high rpms and even under cranking conditions. To quickly diagnose the kill switch simply disconnect the black wire with white tracer(stripe) on it behind the headlight area. It is a single wire by itself with a barrel style connector. Ususally clear wrap around it. That will disable your kill switch. On warriors the switch closed to short out the ignition. You will be breaking the circuit to the kill switch. If that does not eliminate the cut out problem you can open the connection to the ignition switch.(key switch) and put a jumper wire across it (refer to a wiring diagram for the proper two wires.) and try the bike. Try the kill switch 1st. Before getting into the cdi etc. !st the kill switch, then the ignition coil primary signal test, then check the battery voltage. In that order.

 

Thanks, that was some EXCELLENT information. I will try the test light on the coil today. I may have to purchase an analog meter, all of ours are digital. I checked all the resistances on the stator yesterday and it checked out ok, I'll check for voltages today.

Someone mentioned it could be valve float. YIKES! The coil test should tell me if the ignition is OK. I hope its not the head, but at this point I am just hoping for anything definitive.

Aaron

 

there is a wire on your clutch handle.it looks like a plug that just plugs into your clutch lever bracket.you can cut that wire and see if it will start ,if not then just wire the two wires together.Ive seen this done a dozen times and always solves your cutting out problem