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2001 Yamaha 2 stroke 150hp compression readings
#12698933
04/02/18 03:41 AM
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Joined: Mar 2003
Posts: 1,079
Cvillemudcat
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Extreme Angler
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OP
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Posts: 1,079 |
Looking for some input on compression readings as this is my first time dealing with a Yamaha outboard. I'm looking at a bay boat with a 2001 Yamaha 150hp 2 stroke. My compression results were all in the 90psi range for all 6 cylinders. The lake test was good except for a mid range stumble that would go away if you push in the key to squirt a little more fuel in. So it has a fuel issue that needs attention; but what about those compression numbers? I have always had Rude and Johnson motors and good working compression was in the 105 to 120 range. Does anyone know the normal compression range on a carburated Yamaha 2 stroke 150 hp made in the early 2000s? Any input would be appreciated as I'm looking to decide in the next day or 2. Thanks
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12698965
04/02/18 04:53 AM
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Joined: Sep 2009
Posts: 3,644
Droyhef
TFF Team Angler
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TFF Team Angler
Joined: Sep 2009
Posts: 3,644 |
Had that fuel issue before and it was water in mine.
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699366
04/02/18 02:40 PM
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Joined: Mar 2003
Posts: 1,079
Cvillemudcat
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Thanks and yeah that may be the case on this one too. I just really want to be sure about those compression numbers before I buy this thing. Normal compression readings, anyone?
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699401
04/02/18 02:54 PM
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Joined: Mar 2010
Posts: 25,824
T Bird
TFF Guru
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TFF Guru
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Hot or cold compression check? Was throttle full open?
Last edited by T Bird; 04/02/18 03:05 PM.
Okie by birth, Texan by choice. USAF "Thunderbirds" Alumni 1985-1989
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699425
04/02/18 03:06 PM
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Joined: Mar 2003
Posts: 1,079
Cvillemudcat
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Hot, it was right after the lake test. I didn't have the throttle plates wide open, but that never made much difference when doing compression checks on Johnny and Rudes. Not sure if Yamaha would be much different in regards to that. No hour meter, so hours are unknown.
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699451
04/02/18 03:18 PM
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Joined: Mar 2010
Posts: 25,824
T Bird
TFF Guru
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It will result in lower compression readings on Yamaha's. From everything I've found on 2000 to 2003 150 HPDI's you should be seeing around 110 psi on hot motor with throttle full open.
Last edited by T Bird; 04/02/18 03:19 PM.
Okie by birth, Texan by choice. USAF "Thunderbirds" Alumni 1985-1989
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699463
04/02/18 03:28 PM
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Joined: Mar 2003
Posts: 1,079
Cvillemudcat
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Ok, thanks for the input. Do you think with the throttle plates closed it could result in a 10 to 20 psi lower reading?
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699499
04/02/18 03:52 PM
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Joined: Mar 2010
Posts: 25,824
T Bird
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Ok, thanks for the input. Do you think with the throttle plates closed it could result in a 10 to 20 psi lower reading? Sorry, no idea what the reduction amount would be.
Okie by birth, Texan by choice. USAF "Thunderbirds" Alumni 1985-1989
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699701
04/02/18 05:47 PM
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Joined: Apr 2017
Posts: 12,178
tmd11111
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You need to recheck it with the throttle fully open, it will make a difference. As for 90, that is borderline low enough to not even ignite the fuel.
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12699730
04/02/18 05:57 PM
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Joined: Apr 2015
Posts: 1,818
Curtbass
Extreme Angler
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Thats low & getting near rebuild time
ELITE POWER SYSTEMS/ Elite Fishing Products Lithium Battery & Charging Systems, Soft Plastics, Tackle,Tokyo Rigs Tight lines & stay safe out there.Gods blessings
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Re: 2001 Yamaha 2 stroke 150hp compression readings
[Re: Cvillemudcat]
#12700543
04/03/18 02:49 AM
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Joined: Dec 2008
Posts: 16,181
grout-scout
TFF Guru
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My 1999 vmax 150 read 125 on 1 cylinder and 130 on the others. I suppose some gauges could read differently though.
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