|
Forums59
Topics1,057,227
Posts14,281,475
Members144,604
| |
Most Online39,925
Dec 30th, 2023
|
|
 Re: Question For Yamaha SHO Owners
[Re: BigDozer66]
#12874936
08/24/18 03:15 AM
|
Joined: Apr 2012
Posts: 56
Matt Newsom
Outdoorsman
|
|
Outdoorsman
Joined: Apr 2012
Posts: 56 |
If you are running less than 89 octane you run the risk of preignition and having the motor pull timing. 89 octane is the [censored] gas at the pump though. 89 is used the least and sits the longest at the station. It will soak up the most water and be the oldest gas at the station. On the 200 you are only getting 20 percent throttle opening so you peak cylinder pressure will be lower and you will be less likely to have it pull timing. I would still want the octane if it was my engine. What octane does Yamaha recommend? On my 115 VMAX SHO 4 stroke Yamaha recommends 87 minimum octane for inland use.  Using higher than recommended octane will cause detonation and cause the engine retard the timing to correct the issue. If outboards are equipped to correct the timing like automobiles do?  Using higher than recommended octane will most certainly not cause detonation. And it depends on the motor but the SHO does have a single nock sensor that is located behind the ECU that listens for specific detonation frequencies. Using higher than recommended octane will not hurt anything other than your pocket book. There will be someone who will pipe up that it will lead to carbon deposits and another guy will pop up and says it has less energy and will not run as well. Both are incorrect. (Technically higher octane does have slightly less energy because its composed of more short chain molecules. But its not enough to make a noticeable difference.)
|
|
|
Re: Question For Yamaha SHO Owners
[Re: Matt Newsom]
#12874981
08/24/18 03:55 AM
|
Joined: Mar 2012
Posts: 11,008
BigDozer66
TFF Guru
|
|
TFF Guru
Joined: Mar 2012
Posts: 11,008 |
If you are running less than 89 octane you run the risk of preignition and having the motor pull timing. 89 octane is the [censored] gas at the pump though. 89 is used the least and sits the longest at the station. It will soak up the most water and be the oldest gas at the station. On the 200 you are only getting 20 percent throttle opening so you peak cylinder pressure will be lower and you will be less likely to have it pull timing. I would still want the octane if it was my engine. What octane does Yamaha recommend? On my 115 VMAX SHO 4 stroke Yamaha recommends 87 minimum octane for inland use. Using higher than recommended octane will cause detonation and cause the engine retard the timing to correct the issue. If outboards are equipped to correct the timing like automobiles do? Using higher than recommended octane will most certainly not cause detonation. And it depends on the motor but the SHO does have a single nock sensor that is located behind the ECU that listens for specific detonation frequencies. Using higher than recommended octane will not hurt anything other than your pocket book. There will be someone who will pipe up that it will lead to carbon deposits and another guy will pop up and says it has less energy and will not run as well. Both are incorrect. (Technically higher octane does have slightly less energy because its composed of more short chain molecules. But its not enough to make a noticeable difference.) You are correct I meant to say lower instead of higher.  Some 4 Strokes are able to take advantage of higher octane but the results might not lead to that "Seat of the pants" feeling that some expect it to! 
2016 Ranger RT188 Charcoal Metallic Dual Console 2017 Yamaha 115 VMAX SHO (VF115LA) SS Prop Minn Kota Ultrex i-Pilot Link 45" 80 lb. Humminbird Helix 10 Mega SI BalZout Console Humminbird Helix 10 Mega SI BBT Bow Mount Trick Step ![[Linked Image]](http://img.photobucket.com/albums/v373/BigDozer66/Boating/Ranger%20Boats%2050%20Years_zpsqe1kjywq.jpg)
|
|
|
Re: Question For Yamaha SHO Owners
[Re: Don G]
#12887107
09/04/18 09:10 PM
|
Joined: Jan 2011
Posts: 3,610
PlanoKeith
TFF Team Angler
|
|
TFF Team Angler
Joined: Jan 2011
Posts: 3,610 |
89 is mixed at the pump. I used to work for a company that built gas stations and the tank and pump installers said that is how it is done. I know this because they would only put two tanks in the ground and i asked them why not three? He said all we need is 93 and 87 . The pump increases the octane. That is what i was told 
Keith
|
|
Moderated by banker-always fishing, chickenman, Derek 🐝, Duck_Hunter, Fish Killer, J-2, Jacob, Jons3825, JustWingem, Nocona Brian, Toon-Troller, Uncle Zeek, Weekender1
|
