I have a 2002 Vmax 250 OX66 on a 26' Playcraft triple tube pontoon boat. Last week when I took off down the lake the overheat alarm went off after about 5-10 minutes of cruising at around 4000-4200 rpms. I shut it down for a few minutes and made sure nothing was clogging the inlets and took off again. Closely watching the water pressure guage I noticed that it was fine (anywhere from 12-20 psi at 3000-3600 rpm), but when I would open it up a little (over 4000-4200 or so) the pressure would start to drop - all the way down to 5psi or lower. If I slowed down again, the pressure would go back up again to normal. The water stream was good and steady coming out of the engine.
I spoke to a mechanic at the lake who said it was probably the impeller in the water pump. Had it replaced and went out the next day with the same problem. When I got the boat home, my local Yamaha mechanic talked to the people at Yamaha who were almost certain it was the poppet valve. He removed it, cleaned it and flushed the system real good. I had the boat on the lake yesterday and the same problem persists. We bought this boat used last September with 66 hours on this engine, and it has been great up until this point. Engine has around 83 hours on it now. Any suggestions would be great. Thanks!
I kinda doubt they talked to anyone at yamaha since at high speeds the poppit valve is pretty much out of the loop.
are you positive it was an overheat? did you get a visual and RPM reduction?
the same tone is used for all alarms and is differentiated by the visual indicates.
post the complete model number.
also what angle of trim was being used?
on toons we find load and trim can create air around the water intakes.
did the tech replace the entire water pump kit or just the impeller?
was the housing carefully inspected for signs of melt ?
has this unit ever seen salt or brackish water ?
I did get an rpm reduction, steady tone on the alarm. I'm still getting used to these digital gauges and I couldn't swear to the overheat visual. I do know that by waiting for the engine to cool off (5-10 min.), I could start back up with no alarm.
Trim angle was towards the upper end (between 4 & 5 on guage), but I tried different trim angles which made no difference. As far as the load goes, the first time problem occurred there were only 2 people on board. This weekend we had 7.
Tech replaced only the impeller, not water pump. Said everything looked good upon inspection.
Boat has not been in salt or brackish water.
Model # is VX250TLRA.
Thanks!
you have a Vmax OX66 EFI 3.1L 2002 motor.
all alarm tones are the same for any alarm. they are Identified by the visual indicate on the guages.
alarm can be triggered by low oil level in the engine tank due to a restricted remote tank filter, overheat,loose battery cables low battery voltage and a few other things.
we see a lot of the RPM reduction and alarms that are due to a restricted remote tank filter, the engine at high speed can consume oil faster than the transfer can occur, alarm sounds RPM slows and the tank can refill.
I belive your 3.1L is also covered by a tech bulliten on the T-stst housing, check with your dealer for further informtion.
This is weird I have had the same problem with our 28 foot Playcraft Tritoon pretty much since the day we purchased it. In fact we seized the first 225 Yamaha not knowing what the problem was. Since 04 we have had a lot of the same issues with the new 225 as soon as you exceed 3500 RPM pressure drops off completely. If you slow back down the pressure slowly comes back. All the techs including Yamaha and Playcraft say they don't know and they've had no one else complain about this issue. I finally installed a temp gauge to monitor engine temp
I've done all the same repairs including complete water pump kits and poppet valve replacements but nothing fixes the issue, there must be a substantial amount of cavitation that causes the pump to lose prime.
I'm to the point that I am going to install a low water pickup somewhere on the boat where I get clean water away from all the white water
2002 Yamaha Vmax 250 OX66 Overheat Alarm
Linear Mode
