OK guys I have an 88 TRX250R pretty much stock. It has been bored .020 and has a KN filter and DG pipe and silencer. At 44 I do not ride a lot, mostly sand dunes and trails, it does get rode extremely hard or for extended periods of time. The problem is that it seems the low end has slowly went away, the quad idles great and even runs pretty good through the mid range, it may not pull quite as hard through the top as it use too. The machine also starts easy the spark plug reads dead on to slightly rich. Any ideas on the problem, or what to change would be apprectiated

 

Sounds to me like you just slowly lost your compression. Have you ever checked it before? If so, use the same gauge to check it again and compare results. Most mid priced gauges will show about 175 lbs. for an R like you described in good running order. If you think your compression is low, check out the cylinder walls for any big scratches and if it looks good, just have it honed and throw on a new set of rings. From what you said, it sounds like that's all you'll need.

JP