roger3645
Petty Officer 1st Class
- Joined
- Aug 30, 2005
- Messages
- 271
This is an update, just wanted to throw it out there since I found the problem with the high rpms.
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. Also, while running it in the driveway, I guess I let it run too long at these high rpms and it got hot as it fried the rectifier I saw smoke come from it. I replaced the rectifier and added a temp gauge, still high rpms. The coils and power pack were replaced 3 years ago.
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.
Well I found the high idle problem. Turned out to be the 4 wires from the power pack, blue, green, white, and purple. If I wiggle these wires (pull away from the block) the idle will increase dramatically. If I push them toward the block the idle will go back down. I guess I could try and see if it's only one of the wires and try a repair. But better off with new power pack.
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. Also, while running it in the driveway, I guess I let it run too long at these high rpms and it got hot as it fried the rectifier I saw smoke come from it. I replaced the rectifier and added a temp gauge, still high rpms. The coils and power pack were replaced 3 years ago.
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.
Well I found the high idle problem. Turned out to be the 4 wires from the power pack, blue, green, white, and purple. If I wiggle these wires (pull away from the block) the idle will increase dramatically. If I push them toward the block the idle will go back down. I guess I could try and see if it's only one of the wires and try a repair. But better off with new power pack.
