I have a WR426 that has been displaying some strange intermittent issues. It's got alot of km's on it and has a very noisey motor and I assume it's due for a rebuild. I've been experiencing this problem where while I'm riding it suddenly starts loosing power and eventually shuts off. Sometimes it starts spluttering and popping but if I try keep up the revs it will come back and not die but it will eventually do it again. When it dies it becomes very difficult to start, push starting is usally out of the question. I usually have to wait about 20 minutes and just keep kicking it through and then eventually it will start again. While trying to kick it through it can either feel like it has no compression or that it is flooded and not getting any spark This problem is random and sporadic and may not happen at all while riding or it may happen a lot, sometimes to the point I can not get it started again. It generally feels like it's been running rough, however when it is running it usually runs pretty well and still has plenty of pull. First starting it is a bit hit or miss, it's either pretty easy or it takes many many kicks to get it going. I also have the classic WR426 ailments like bogging and hanging idle, in fact the hanging idle only really started happening when this problem appeared. Before this happened, it had just come back from a big service and was running the best it ever has. I think so well that I got a little carried away with it
I checked and adjusted my valve clearances about 800km's ago and again today. They are in spec. I also cleaned the carb the other day, it was generally pretty clean except for some grease up the top of the carb. Checked the electrics as per the manual, they were good.
Can anyone provide any information or advice about this situation. I'm just wondering if there's anything else I can check. I was thinking maybe I had sticky valves. It's just weird that the problem is so random and intermittent in nature. Any help will be so greatly appreciated.