R ignition troble

[airheadedduner]

I don't think my R wants me to sell it cause it won't run right:o

It runs awesome...for 10 minutes. Then it sputters and dies and fauls the plug. If I check the plug in the first 10 min it is a nice medium tan color. Power is awesome and throttle response is crisp. Then it just dies. I am thinking the coil or cdi is going bad and after heating up it is failing. Does anyone else have any ideas???

[wilkin250r]

You can easily test that theory if you have an inductive timing light (where the trigger clamps over the spark plug wire) Run it for 10 mins. and if the timing light suddenly stops triggering, you know that your spark died.

However, I'm skeptical. I don't think CDIs slowly go bad. I think it's more of a black or white issue. They either work properly, or they don't work at all.

[airheadedduner]

Thats what I thought about cdi's too but I have heard of that happening. It could be the coil doing that though. I don't have a spare one of thoose though:(

[250RXCrider]

My R had the same problem, when it got hot it would sputter then die. At this point there was no spark and it would start after it cooled off. It finally good so bad that it would not start at all and had no spark. I had it tested with an ohm (sp?) meter and the stator was bad. I just got the new one in and I will let you know what the outcome is.

[250rpilot]

definately sounds like a stator problem, i had the exact same issue and after hours upon hours of testing and replacing parts, a new stator solved the problem.

if it is your stator, wait till you put the new one on- it will have a few more ponies cuz of the hotter spark- at least it made a world of difference for me!!:D

[RUNMYTA]

I kinda had a problem like yours on my 89R. It would run great for the first 5 to 10 min and then it would sputter and miss real bad in the upper RPMS. After several days of changing parts off of my buddies R we found out that I had replaced the bad coil with another faulty coil!! Sounds like the coil is going. MIKE

[airheadedduner]

Update, think I got it. Coil tested good, I bought a new one anyway, cdi is fine. The stator I pulled out(I have two) which I though was causeing me problems before tested 192ohms cold yesterday, after heating it for about 20 min with a hair dryer I could only get it up to 231 ohms. Today it tested between 188-229ohms. Now, the stator that I replaced it with in the bike tested 196ohms cold. Today I checked it and it was 192, heated it with a hair dryer for only 10 min and it hit 249ohms. The book said it should be between 50-250ohms. I read somewhere else that that is too large of a range and you should be between 185-235ohms. So it sounds like after getting hot I am getting too much resistence and can't get enough spark. So I think that is my problem. Thanks for the ideas:)