Post by rip3645 on Oct 4, 2008 11:05:14 GMT -1
I’m just stumped on this one. I’m running a 1991 70hp Johnson. It first started acting up when it would not get my top rpms, would not run over 4000 rpms. After going over the fuel system, taking apart and cleaning the carbs and fuel lines, still the same. Then it got worse and I noticed the fuel coming out the carbs was milky. To me that indicated water in the fuel. First I thought I may have pumped some water in the tank when I bought fuel. Which would not have been the first time. But that wasn’t it. I did a compression check and cylinders 1 and 2 were at 90PSI and #3 was at 120. Originally all 3 were at 120. I replaced the head gasket and now all 3 are back to 120. Now when I start her up she will not idle under 2500 rpms. It did this once before and it kind of fixed itself. Don’t know why it is doing this. I know it is not the linkage, the butterflies on the carbs are closed, the timing base is in the idle position, the link & sink is correct and the idle screws in each carb, are set correctly. I haven’t had it back on the lake since the repairs and I’m running on muffs in the driveway. I’m hoping once I put it in the water with some backpressure it will correct itself again or just running the motor on the lake will help. If not I’m just lost. 
