I have twin 225 Yamaha OX-66 outboards on my boat. I have been experiencing multiple issues with the starboard motor and I would be grateful if mr. rodbolt and others can let me know their thoughts on it.
Issues:
1.Smoky and shaky at idle
2.High oil consumption (2X as much as the other one)
3.Higher fuel consumption (10-15%) per fuel management gauge
4.High Temp alarm when idling with gear engaged
5.Sometimes motor won't crank even though the controller is in neutral.
I figured the 1-3 were related. #4 could have been somewhat related to 1-3 but not likely. I figured #5 is related to the neutral switch on the control unit.
First, to address #4, I replaced the impeller, all thermostats, and pressure relief valves on both motors, and it seems to have fixed it. I suspect the culpit was the PRV but I replaced all the rest any way to be sure.
To address the issues #1,2, 3, I first replaced the O2 sensor, spark plugs, and then adjusted the oil rod. Switching the O2 sensor fixed the fuel consumption issue but it was still smoking bad at times at idle. Ajusting the oid rod did help a bit but it still smokes sometimes and the motor shakes considerably more than the other one.
I was a bit conservative with the oil rod ajustment and I think it may help to adjust a bit more (there is quite a bit thread left for me to adjust). In addition, I am wondering whether to replace the low pressure fuel pumps, since I don't see any record of the previous owner doing that. I have not done any compression check to see if this is a mechanical issue. But, the motor runs well at higher RPM with no smoke and with plenty of torque. I use Yamalube and Ringfree.
As for the #5 issue, should I try to replace the neutral switch or is there some adjustment that I can do fix this? I can usually start if I push the controller up and down.
I would appreciate your thoughts on these issues. I have read many (if not all) posts on OX-66 motors on this forum and learned a lot especially from rodbolt's posts. Thanks in advance!
Issues:
1.Smoky and shaky at idle
2.High oil consumption (2X as much as the other one)
3.Higher fuel consumption (10-15%) per fuel management gauge
4.High Temp alarm when idling with gear engaged
5.Sometimes motor won't crank even though the controller is in neutral.
I figured the 1-3 were related. #4 could have been somewhat related to 1-3 but not likely. I figured #5 is related to the neutral switch on the control unit.
First, to address #4, I replaced the impeller, all thermostats, and pressure relief valves on both motors, and it seems to have fixed it. I suspect the culpit was the PRV but I replaced all the rest any way to be sure.
To address the issues #1,2, 3, I first replaced the O2 sensor, spark plugs, and then adjusted the oil rod. Switching the O2 sensor fixed the fuel consumption issue but it was still smoking bad at times at idle. Ajusting the oid rod did help a bit but it still smokes sometimes and the motor shakes considerably more than the other one.
I was a bit conservative with the oil rod ajustment and I think it may help to adjust a bit more (there is quite a bit thread left for me to adjust). In addition, I am wondering whether to replace the low pressure fuel pumps, since I don't see any record of the previous owner doing that. I have not done any compression check to see if this is a mechanical issue. But, the motor runs well at higher RPM with no smoke and with plenty of torque. I use Yamalube and Ringfree.
As for the #5 issue, should I try to replace the neutral switch or is there some adjustment that I can do fix this? I can usually start if I push the controller up and down.
I would appreciate your thoughts on these issues. I have read many (if not all) posts on OX-66 motors on this forum and learned a lot especially from rodbolt's posts. Thanks in advance!