I have a 2000 Yamaha 200 hp saltwater 2 series. Overheats at idle and then when I raise the RPM for a minute or so the alarm is still going off so I shut it down. I'm going to replace my poppet valve to see if that does it. I've already replaced both thermostats and the impeller. I don't know if the alarm would have stopped if I ran it longer at high RPM, but I didn't want to because I was worried about damage. How long would you have to run it at high RPM to get the alarm to go off if it was just to pop it valve?
Probably 30 sec to a minute. But if the alarm is going off you did the right thing to shut her down. Best thing to do is get an IR thermometer that you can point at the block and see that it’s actually over heating and you can rule out a bad overheat sensor. Sometimes the wiring will ground itself and cause faulty alarms. Also it does happen where the impeller is put on the wrong way. (Counter or clockwise positioning of the splines) this will cause insufficient water up the water tube. Another thing to look for is mis alignment of the water tube to the impeller housing when reinstalling the lower unit. All things to look at and mark off the list when trying to diagnose. The poppet does cause alarms when in low rpm or idle, if it has debri leaving it open or the gaskets have failed. Good luck 👍🏽 let us know what you find
@@ReelTeaseFishing the impellers definitely clocked the right way. I turned the shaft clockwise while pushing down on the housing. But since I left this message I've read quite a few threads about the ox66 overheating using earmuffs. That's what I'm using. So I'm going to back it down into the water and see if it's still overheats. I've been doing all this testing using earmuffs.
@@gurnblanstein9816 ahh yeah! That definitely could have been it. Some engines don’t like earmuffs. Mainly due to low water pressure at the hose. Hope that’s it
@@gurnblanstein9816 My OX66 150 will always overheat on the muffs after about 5 minutes. I've had the overheat at idle before and replaced my poppet valve. When it goes off at idle, I'd just hit the throttle if it didn't stop the alarm after a minute, I'd shut down and try again. Second time it would alwys stop and be fine as long as I was on plane.
Thanks for the tip my 2001 Yamaha 150 2stroke will run fine at 3200rpms as soon as I push it up to 4K it will run for about 5 mins then stall out and I have to wait about 2min to resume could this issue be bc of a bad poppit?
hi Craig, hope you found the answer by now. this engine has a PCV (Pressure Control Valve) very similar to the poppet valve but its all in one piece. it is located in the rear area topside of the mid section. you will need to remove the sides of the lower cowling area to reach it.
the poppet valves usually stay in relatively good shape. its the oring or sealing grommet that goes bad. signs of a bad poppet valve are overheating at idle and it going away when you raise RPM's
Great tip, thanks!
Good Call About Dowel.
Thanks
I have a 2000 Yamaha 200 hp saltwater 2 series. Overheats at idle and then when I raise the RPM for a minute or so the alarm is still going off so I shut it down. I'm going to replace my poppet valve to see if that does it. I've already replaced both thermostats and the impeller. I don't know if the alarm would have stopped if I ran it longer at high RPM, but I didn't want to because I was worried about damage. How long would you have to run it at high RPM to get the alarm to go off if it was just to pop it valve?
Probably 30 sec to a minute. But if the alarm is going off you did the right thing to shut her down. Best thing to do is get an IR thermometer that you can point at the block and see that it’s actually over heating and you can rule out a bad overheat sensor. Sometimes the wiring will ground itself and cause faulty alarms. Also it does happen where the impeller is put on the wrong way. (Counter or clockwise positioning of the splines) this will cause insufficient water up the water tube. Another thing to look for is mis alignment of the water tube to the impeller housing when reinstalling the lower unit.
All things to look at and mark off the list when trying to diagnose.
The poppet does cause alarms when in low rpm or idle, if it has debri leaving it open or the gaskets have failed. Good luck 👍🏽 let us know what you find
@@ReelTeaseFishing the impellers definitely clocked the right way. I turned the shaft clockwise while pushing down on the housing. But since I left this message I've read quite a few threads about the ox66 overheating using earmuffs. That's what I'm using. So I'm going to back it down into the water and see if it's still overheats. I've been doing all this testing using earmuffs.
@@gurnblanstein9816 ahh yeah! That definitely could have been it. Some engines don’t like earmuffs. Mainly due to low water pressure at the hose. Hope that’s it
@@gurnblanstein9816 My OX66 150 will always overheat on the muffs after about 5 minutes. I've had the overheat at idle before and replaced my poppet valve. When it goes off at idle, I'd just hit the throttle if it didn't stop the alarm after a minute, I'd shut down and try again. Second time it would alwys stop and be fine as long as I was on plane.
Thanks for the tip my 2001 Yamaha 150 2stroke will run fine at 3200rpms as soon as I push it up to 4K it will run for about 5 mins then stall out and I have to wait about 2min to resume could this issue be bc of a bad poppit?
This seems like a fuel restriction issue.
A poppet issue would cause an overheat alarm.
Great videos. I own a 2002 f225 xtra yamaha. Does it have a poppet valve? If so, do you know the location of it?
hi Craig, hope you found the answer by now. this engine has a PCV (Pressure Control Valve) very similar to the poppet valve but its all in one piece. it is located in the rear area topside of the mid section. you will need to remove the sides of the lower cowling area to reach it.
How do you know if you need to change out the poppet valve? I switched mine out the other day on a 2002 200hp Yamaha and it look good shape.
the poppet valves usually stay in relatively good shape. its the oring or sealing grommet that goes bad. signs of a bad poppet valve are overheating at idle and it going away when you raise RPM's
Good tip!
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