MadAero Posted June 9, 2009 Share Posted June 9, 2009 Hi, I'm new to the forum as I have just purchased my first street bike, a 1986 Yamaha Radian. I'm having a couple of problems that are really giving me a headache. First, the bike runs fairly well for the first 10-15 mins or so. When you roll on the power it runs slightly rough up until about 5000 rpm, then it cleans out and pulls hard to redline. It runs like this consistently for 10-15 mins, then all of a sudden it starts running only on cylinders 1 and 4. Cylinders 2 and 3 still have spark, but I can unplug them and it has no effect on how it runs. If I unplug 1 or 4 it dies instantly. Second problem. Should the starter disengage after the engine fires? Sometimes after I shut the engine off I swear I can hear the starter disengage and spin down? After the motor has run for several minutes if I shut it down I can't restart it. It sounds exactly like a weak battery. Sometimes it just doesn't have the power to turn the motor fast enough, sometimes only the solenoid clicks. I have had the battery load tested at two shops and they both say it tests ok. The previous owner also claims the battery is only a year old. The starter is also burning hot to the touch. Are these two problems somehow related? Almost seems like a heat issue at times. Anyone run into this or steer me in the right direction? Thanks in advance!!! Link to comment Share on other sites More sharing options...
rikernumber1 Posted June 10, 2009 Share Posted June 10, 2009 Hi, I'm new to the forum as I have just purchased my first street bike, a 1986 Yamaha Radian. I'm having a couple of problems that are really giving me a headache. Second problem. Should the starter disengage after the engine fires? Sometimes after I shut the engine off I swear I can hear the starter disengage and spin down? After the motor has run for several minutes if I shut it down I can't restart it. It sounds exactly like a weak battery. Sometimes it just doesn't have the power to turn the motor fast enough, sometimes only the solenoid clicks. I have had the battery load tested at two shops and they both say it tests ok. The previous owner also claims the battery is only a year old. The starter is also burning hot to the touch. Are these two problems somehow related? Almost seems like a heat issue at times. Anyone run into this or steer me in the right direction? Thanks in advance!!! Check the starter connections - also check it's bolted tight. However, the fact it's running hot doesn't sound good. Link to comment Share on other sites More sharing options...
MadAero Posted June 11, 2009 Author Share Posted June 11, 2009 OK, so I pulled the carbs today and found that prev owner had used silicone on the float bowl gaskets. Obviously not a good idea as it swelled up and plugged several jets. I cleaned them out and now the bike runs great. So now just the starter problem. After some research in the service manual I see there is a starter clutch. I'm assuming if the starter is being backdriven then there is a problem with the starter clutch? Is this something that can be inspected and serviced with the motor on the bike or does it require major overhaul. Thanks for any help!!! Link to comment Share on other sites More sharing options...
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