I have a 1987 250 r quad and can't seem to get it running right. It starts and runs good but when you open it up, it is like it is to rich and doesn't pull hard on the upper two thirds of the throttle. It WANTS to, but just kind of bobbles. WE thought it was the jetting but has stock 265 main in it, which in itself should be lean because it has a FMF Fatty pipe on it with silencer and with the pipe, it actually should be jetted richer. We have changed the jetting around and doesn't seem to make much difference one way or another. It has 160 PSI compression. Then we decided that it sounded more like an electical problem and thought that the cdi or coil might be weak. Changed them with no changes in performance. I am open for any informed advice or if someone else has had this problem and if so, what did you do to correct it? Thx...Dean

 

Are you sure you have a stock carb on it a 87 250r should have a keihin PJ07A it has a 152 main jet. I run a 150 in my 250r with 36mm Keihin carb. I have FMF exhaust and don't run lid on air box.

 

I think I do but will check tomorrow. I wrote that it had a 265 main but I have a bad case of fat finger when I type and I believe it is a 165. Carb is a Keihen but will check my infor. Getting old and feeble. Thx and will get back to this tomorrow....Dean

 

Well, I was completely wrong. It is a stock PJ but the main in it is a 150. So much for the memory lesson. However, I was talking to a fellow who said he had a similar problem and it was the rectifier/regulator. when it was opened up, it would only run like mine does. Does anyone know if this could be a possibility? We have pretty much ruled out anything else such as switches and etc by wiring around and eliminating them, which made no difference. Can't be much left. Anu input would be appreciated. Thx...Dean