I just ran my boat for the first time this year in order to change the oil. As I was running it I noticed that one of the risers was a little warmer than the other. The water flow out that side was about 80% of the other. I'm not sure if this may be because I was using the flush kit or if I may have some corrosion in that riser. The temp never did get above 150 and I probably wouldn't have noticed if I hadn't touched the risers. I was wondering if it is worth pulling off the risers or just wait to see how it is during the first run out on the lake.