my tach goes nuts at higher rpm's and get this idles betyter out of the water

[BOATING1]

I have 1984 140 horse johnson(j140tlcrd)yesterday I hit a wake from another passing boat then my tach started to go up and down real fast, works up to 3000 rpm after that starts to flicker,also form a previous POST I did clean my carbs the boat started right up with the garden hose connected to it but when its in the water it doesn't idle like it would out of the water.<br /><br />Checked plug wires coils all good, by the way a dealer is telling me to use differant plugs then what the boat tells me to use, what are the best plugs???

 

[moderator1]

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Champion plugs only...unless you need the practice of changing pistons....<br />Engine idles usually higher RPM out of water because it has no back-pressure...should be an adjustment issue...not uncommon.<br />The tach???? Maybe a good one for Joe Reeves...

 

[o/b tech]

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Maybe a loose wire at the tach?

 

[BOATING1]

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Loose wire on the tach meaning at the tach itself or could it be a loose wire going to the engine, I dont have a manual, not sure.....

 

[o/b tech]

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Re: my tach goes nuts at higher rpm's and get this idles betyter out of the wat

Try checking the wiring at the dash first. Make sure eveyting is tight.