Trumangang
Recruit
- Joined
- Jul 20, 2014
- Messages
- 4
Long-time reader, first time poster.
My 1987 Johnson 70hp – VRO, has an issue. The last 2 time that I had it out it started up and ran great, and then it bogged down, lost power and acted funny. The video links below show the last time it time it happened.
1[SUP]st[/SUP] time - For no apparent reason (running wot) the motor bogged down, I tried playing with the throttle, I put in neutral and it stalled. Looked like it got “HOT”, bit of smoke but not a lot, thought it sucked up weeds or something. Not sure if the cooling system was Peeing when it shut down, so I did not try to restart it. The next day I took it home and got it running in my driveway (muffs on) and it was running as usual with water coming out the pee hole. I took it to a local marina and had them check the carbs and idle. They made a few minor tweaks and everything seemed fine when I tested it in the driveway again.
2[SUP]nd[/SUP] time - I took it to the lake and as usual she started and ran like a champion. Cruised it at 75% throttle for 10 minutes. I then went to wot for another 5 to 10 minutes. While running at wot, it bogged down (loss of power) and I quickly put it in neutral and it stalled. No smoke and no symptoms that I could recognise to cause the issue. The fuel ball was hard-ish, certainly not empty or sort-of empty, I gave it a slight squeeze and left it alone. I tried to start it and it was not interested. After 5-10 minutes and trying to start it every now and again it finally sputtered a bit. On the next try it came to life as usual and I started filming the next 7 minutes of video.
3[SUP]rd[/SUP] time - For a minute and a half she ran great, like it usually does. http://youtu.be/hBw9fk2stnU WOT 5500ish - just ripping along and then without a warning or me touching the controls it just starts to bog down and lose power. It speeds up and slows down all on its own, never getting more than 4400rpm.
After 2 minutes of it running poorly in WOT (it is still speeding up and slowing down on its own) I put the motor in neutral. It did not stall so I left it running. It sounds bad and when I take the shroud off it sound worse. Sort-of like something is knocking or miss-firing. Here is a video of that http://youtu.be/Ptqj42GYrFQ
This last video shows the motor running poorly and limping back to the dock. http://youtu.be/Qts9lqhXOXo
Electrical issue?, Overheat sensor, thermal switch or something like that?, Bad gas? , Water in the tank? Bad oil mix from the VRO?
I would like to get to the bottom of this mystery, your thoughts are welcome.
Thanks
Truman
My 1987 Johnson 70hp – VRO, has an issue. The last 2 time that I had it out it started up and ran great, and then it bogged down, lost power and acted funny. The video links below show the last time it time it happened.
1[SUP]st[/SUP] time - For no apparent reason (running wot) the motor bogged down, I tried playing with the throttle, I put in neutral and it stalled. Looked like it got “HOT”, bit of smoke but not a lot, thought it sucked up weeds or something. Not sure if the cooling system was Peeing when it shut down, so I did not try to restart it. The next day I took it home and got it running in my driveway (muffs on) and it was running as usual with water coming out the pee hole. I took it to a local marina and had them check the carbs and idle. They made a few minor tweaks and everything seemed fine when I tested it in the driveway again.
2[SUP]nd[/SUP] time - I took it to the lake and as usual she started and ran like a champion. Cruised it at 75% throttle for 10 minutes. I then went to wot for another 5 to 10 minutes. While running at wot, it bogged down (loss of power) and I quickly put it in neutral and it stalled. No smoke and no symptoms that I could recognise to cause the issue. The fuel ball was hard-ish, certainly not empty or sort-of empty, I gave it a slight squeeze and left it alone. I tried to start it and it was not interested. After 5-10 minutes and trying to start it every now and again it finally sputtered a bit. On the next try it came to life as usual and I started filming the next 7 minutes of video.
3[SUP]rd[/SUP] time - For a minute and a half she ran great, like it usually does. http://youtu.be/hBw9fk2stnU WOT 5500ish - just ripping along and then without a warning or me touching the controls it just starts to bog down and lose power. It speeds up and slows down all on its own, never getting more than 4400rpm.
After 2 minutes of it running poorly in WOT (it is still speeding up and slowing down on its own) I put the motor in neutral. It did not stall so I left it running. It sounds bad and when I take the shroud off it sound worse. Sort-of like something is knocking or miss-firing. Here is a video of that http://youtu.be/Ptqj42GYrFQ
This last video shows the motor running poorly and limping back to the dock. http://youtu.be/Qts9lqhXOXo
Electrical issue?, Overheat sensor, thermal switch or something like that?, Bad gas? , Water in the tank? Bad oil mix from the VRO?
I would like to get to the bottom of this mystery, your thoughts are welcome.
Thanks
Truman
