I have a 2018 Yamaha Sho 250 that has lost oil pressure after using Power Tune to get rid of carbon build up. Motor still passes compression test as well as leak down test. Any suggestions of what it might be?
I have a 2018 Yamaha Sho 250 that has lost oil pressure after using Power Tune to get rid of carbon build up. Motor still passes compression test as well as leak down test. Any suggestions of what it might be?
Last edited by BennettPierce; 06-02-2025 at 01:19 PM.
Was there a reason for having to use the Power Tune or was it just preventative maintenance?
Is the low oil pressure alarm sounding with the motor going into RPM reduction mode?
No correlation between low oil pressure and compression pressure that I can see.
I had build up of carbon on port side of motor. No alarm sounding, just killing motor. Also have replaced oil pressure sensor.
What is meant by "killing motor"?
Oil pressure sensor is shutting motor off
I know nothing about these 4 stroke motors. But I would change the oil and use a very good oil filter mayb a Yamaha factory filter.
Wait for yam911 he'll give you the skinny on it.
Test the sensor if possible. A manual screw in gauge in place of the sensor (temporary) for testing possibly. You may get psi just turning the engine over with the starter, pulling the kill switch.
2014 Phoenix 721XP, 250 SHO, Bobs Action Jack, Dual Blades, 112 Ultrex, Garmin Echomap Ultra's Networked, NMEA 2000, 2019 Lariat FX4 F150 Supercrew 4x4
2001 Bumblebee 2100 Super Vee Mercury 225 EFI
1988 Hydrasport Kevlar hull 115 Tower of Power
remove oil filter and open with all filter cutter. Inspect for metal debris. If anything is found, complete disassembly and repair would be required.Originally Posted by BennettPierce
All above good advise. But I would really want to see what is in that oil filter before doing anything else. The mechanical gauge eliminates any of the guesswork after looking in the filter. Cj
2002 X19 200HP OX66 HO Vmax,HPDI lower, it lives, thanks Hydro Tec.
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