Got a question about yamaha digital guages

I have a new to me Skeeter 20i and it has a 250hpdi with the the yamaha guages. I have only put 4 hours on the motor and yesterday was the first day I went fishing in it. The yamaha speed guage has worked flawlessly and matches exact mph on the 332c gps. (until yesterday that is) now it is stuck on 25mph when running. I did notice that i got a little wood in the tiny hole that is on the front end of the nose cone so it is pluged. I know this would effect normal speed guages but did not think it would effect the digital guages. I was thinking that the yamaha guages were somehow connected to the gps unit. Any of you had this problem. Will removing the plugged wood from the nose cone fix this?
thanks,
skip

Yes the speedo reads off the lower unit. Use caution when using a small drill bit to remove the wood, by hand of course.