WOT down and idle not good - '78 Johnson 150

gsbodine

Petty Officer 1st Class
Joined
May 4, 2004
Messages
346
hello folks,<br />my motor has just recently (well, the last two times I had it out) begun to idle worse than usual (actually stalls occasionally now, never did before) and this past time I confirmed that the revs are down 500-1000 at WOT. My thoughts were perhaps I've lost a cylinder or something, or maybe it needs to be decarbed or whatever. Carbs were rebuilt six months ago by a shop, plugs are 3-4 months old and look normal. I am using the same fuel oil mix as always, haven't done anything different to it lately.<br /><br />Oh, and I'll add that in addition to rough idle, it will often stall as I put it into reverse.<br /><br />What would your recommendations of where to start be? I don't have a compression tester. should I just go get one? or is that not the first step? <br /><br />Thanks much guys!
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: WOT down and idle not good - '78 Johnson 150

A compression test is your first step. Go get you one at any auto parts store. Get the kind that screws into the spark plug hole, as opposed to the rubber tipped one that you have to hold against the hole. Let us know the readings...
 
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