speedometer

[67johnson]

I have a 60hp johnson and at full speed the speedometer says like 18 20 mph but my dad drove his boat right next to mine and said i was doing about 28 30 mph it is off about 10 mph wy would this be and how can it be fixed with out replaceing the original speedometer.

 

[trebor0301]

Re: speedometer

Your speedometer tube seems to be plugging up.You should try locating the pitot at the back of your boat and clean the hole out.You can also find a 1/4 inch tube the should be plugged into the back of your speedometer.Detach it from the gauge.Find some sort of air pump like the kind you blow up kids floats and such.Connect the pump into the tube and try to pump air thru it.That usually cleans it out good .Reconnect the tube into the back of the speedometer and It should read correct.F.Y.I.The tube goes from the speedometer to the lower back of the boat into the pitot.

 

[swist]

Re: speedometer

At best, boat speedometers are inaccurate. Newer boats often don't even come with them since most people rely on their GPS.

 

[67johnson]

Re: speedometer

ok thanks for the help i will try to blow it out and see what happens

 

[Marc J.]

Re: speedometer

My old Airguide speedo can be cailibrated (to some extent) by turning the nipple on the back where the tubing attaches. You can get a new pitot and tubing for like $10.

 

[trebor0301]

Re: speedometer

Because of the weed problem on our lake I'm regularly blowing out the speedo tube.(about once a month)I know thats a little overkill,but it only takes a couple minutes.I checked it with a handheld gps.I couldn't believe it. Runs dead on!!I guess the few minutes is worth it after all.