Sticky Mastercraft Speedometer

When i started my 99 MC Sportstar up for the first time this year the guages didn't work...at all. Had the MDC(guage control) module replaced by my dealer, which fixed the guages. My problem now is that my speedo's hardly work at all. They take forever to get up to any speed, and when i slow down to idle they take forever to come back down. Also, when i'm going 32 it reads about 25 on the one speedometer that works "at all". I don't know if it is the fact that i use the boat on the chesapeake bay (brackish, somewhat dirty water) or if the dealer did something wrong when he replaced the MDC(guage control) module. Any suggestions or experience with this problem.

A lot of times stuff can get stuck up in the tubes, this restricts the lines causing the pressure change to be slow and inacurrate. Try removing your dash so you can access the two lines that should be connected behind the gauge. Take some compressed air and blow the lines out. This should take care of your problems. A lot of times bugs get in there over the winter. Just needs a good cleaning.

Do i have to remove the lines from the transom sensors too to blow them out, or only from the dash connection, and in terms of compressed air, would one of the "Computer keyboard duster" compressed air cans work, or would i need something more powerful? Thanks for the help.

I would only remove them from the back of the speedo. Leave them connected at the transom, that was if their is anything stuck in the pickup itself it will also clean that out. Don't know about the can air. I have a compresser and just use that, one of those little 5 gallon tanks for filling flat tires works great if you put a blower/duster don't really know what to call it end on it... basically used for blowing... just put that over/into the hose at the back of the dash and blow the stuff out. Also make sure you have a tight connection when you reinstall the hose on the speedo. Use a small wiretie or clamp and make sure it is tight. Otherwise it will allow water to seap up the line with usage. Then over the winter the water will freeze and bad things will happen! Sorry for the long winded response... any way that should get you going!