Still fighting with my friend's 750K4. Spark plugs 2-4 are a nice light tan. Cylinder 1 plug, whiter than I like and the pipe was beginning to blue around the exhaust collar area. And when I rev the engine, the revs hang a little before settling down. I guessed it was an air leak around the boots, so I sprayed WD-40 around the carb boots on the engine side and also around the airbox side. No change at all in the rpms. Can there still be a leak even though this test is negative? Or should I be looking for something else?
The carbs have been cleaned and floats adjusted, throttle cables lubed and are not binding. Even took the carbs off a second time to double check it all.
It's too late to work on it tonight, so tomorrow Im going to grab a couple cheap hose clamps to see if I can squeeze the carb boots a little tighter on cylinder 1, just to see if it clears up the lean condition.
Im open to any other thoughts on what to look for.