|
Forums59
Topics1,038,881
Posts13,954,751
Members144,181
| |
Most Online39,925
Dec 30th, 2023
|
|
 Merc XR-6 150 Preformance
#12360038
07/26/17 11:59 PM
|
Joined: Jun 2011
Posts: 2,733
militarybrat
OP
Extreme Angler
|
|
OP
Extreme Angler
Joined: Jun 2011
Posts: 2,733 |
I spent a week at the lake I fueled up the boat with 89 octane as I have done for 20 years added seafoam per instructions. It preformed like it always does slight suprise was it ran 5800 in summer heat. Well my son had it out and needed fuel put in 87 at Marina on lake. It lost 400 RPM and would only run 5400 and lost it's snap witch made it easier out of the hole and handeling was boreing for me. The outboard runs a 23 pitch trophy blueprinted by SCP. Tach is good I have 2 they both report the same numbers. I just find it strange how boring it got. Am I losing my mind or would this be common?
TLW I have had several surgeries since I wanted to reseal my powerhead still healing up last one they took 1/2 my first rib and a muscle from my neck still have the other side to go. That said I am doing better than I have in years Hopefully I can get this done in a few months. I appoligise for not getting the boat down to you.
Who ever said nothing in life is impossible.
Never tried slamming a revolving door.
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12360138
07/27/17 01:02 AM
|
Joined: Jan 2005
Posts: 16,912
Pat Goff
TFF Guru
|
|
TFF Guru
Joined: Jan 2005
Posts: 16,912 |
Garbage gas is garbage gas...run it out and refresh with good fuel and see what happens, I wouldn't do anything until then, don't try to fix something that's not broken.
Pat Goff Seadrift TX ![[Linked Image]](https://i.ibb.co/X48Kbbq/scooter-shallow.jpg)
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12360509
07/27/17 05:20 AM
|
Joined: Nov 2006
Posts: 2,848
TLW
Extreme Angler
|
|
Extreme Angler
Joined: Nov 2006
Posts: 2,848 |
TLW I have had several surgeries since I wanted to reseal my powerhead still healing up last one they took 1/2 my first rib and a muscle from my neck still have the other side to go. That said I am doing better than I have in years Hopefully I can get this done in a few months. I appoligise for not getting the boat down to you.
not a deal.. hell, i've had both neck carotids done, two stints in leg since December 6 and memory really sucks so i never noticed! what Pat said.....
Last edited by TLW; 07/27/17 05:21 AM.
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12360623
07/27/17 12:18 PM
|
Joined: Dec 2014
Posts: 1,665
Muzzlebrake
Extreme Angler
|
|
Extreme Angler
Joined: Dec 2014
Posts: 1,665 |
When you pump gas from anywhere you really don't know what you are getting these days.
Typically the higher the octane the cooler and slower the burn thus you are actually making less power.
The more ethanol in fuel the cooler yet leaner the burn also making less power. More ethanol or oxygenators in the fuel requires more fuel to make the same power. In carbed motors this means bigger jets and in injected motors, bigger injectors or increased injector duty cycle thru the ECM calibrations.
My guess is maybe you got some 15% ethanol fuel which would certainly account for the sluggish performance of a motor tuned to run on pure gas.
Last edited by Muzzlebrake; 07/27/17 12:19 PM.
From Genesis: "And God promised men that good and obedient wives would be found in all corners of the earth."
Then He made the earth round...and He laughed and laughed and laughed!
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12361737
07/28/17 01:06 AM
|
Joined: Jun 2011
Posts: 2,733
militarybrat
OP
Extreme Angler
|
|
OP
Extreme Angler
Joined: Jun 2011
Posts: 2,733 |
Muzzlebrake in the northeast U.S. you have always had ethanol in the fuel since the 70's I have never had a problem running it in a Merc still don't no matter where I am at. As far as octane goes I run 89 to prevent detonation (spark Knock) I learned this many years ago melted pistons s--k. The myth that it reduces power is just that a myth. My Merc is a 97 where most of the country was running E-10 so no doubt that Merc knew this and designed and tuned approiately for this. The biggest myth especially where non E-10 was used is to blame the lack of proper maintenence on Ethanol fuel lines break down which is why I switched to auto fuel lines as they do not exibit breakdown from fuel and age like those cheap azz marine lines do.
Most people think that because their owners manual say minimum octane recomended 87 is that it is the only fuel you can run. I will direct your attention to the word minimum it does not say only. I have been building and running internal combustions engines both 2 and 4 stroke since about 1976 yep I'm old. This is just my long term experience with these engines nothing more.
No fix Pat & TLW just thought I was crazy as it is the first time this has happened bad fuel is bad fuel.
Who ever said nothing in life is impossible.
Never tried slamming a revolving door.
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12361824
07/28/17 02:09 AM
|
Joined: Jan 2005
Posts: 16,912
Pat Goff
TFF Guru
|
|
TFF Guru
Joined: Jan 2005
Posts: 16,912 |
I just rebuilt the carbs on my Yamaha jet after a scrape with some garbage fuel. Two filters new lines didn't help when you try to run mud through it.
Pat Goff Seadrift TX
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12362227
07/28/17 12:56 PM
|
Joined: Dec 2014
Posts: 1,665
Muzzlebrake
Extreme Angler
|
|
Extreme Angler
Joined: Dec 2014
Posts: 1,665 |
Muzzlebrake in the northeast U.S. you have always had ethanol in the fuel since the 70's I have never had a problem running it in a Merc still don't no matter where I am at. As far as octane goes I run 89 to prevent detonation (spark Knock) I learned this many years ago melted pistons s--k. The myth that it reduces power is just that a myth. My Merc is a 97 where most of the country was running E-10 so no doubt that Merc knew this and designed and tuned approiately for this. The biggest myth especially where non E-10 was used is to blame the lack of proper maintenence on Ethanol fuel lines break down which is why I switched to auto fuel lines as they do not exibit breakdown from fuel and age like those cheap azz marine lines do.
Most people think that because their owners manual say minimum octane recomended 87 is that it is the only fuel you can run. I will direct your attention to the word minimum it does not say only. I have been building and running internal combustions engines both 2 and 4 stroke since about 1976 yep I'm old. This is just my long term experience with these engines nothing more.
No fix Pat & TLW just thought I was crazy as it is the first time this has happened bad fuel is bad fuel. You ain't old enough then. If you were you would know a little more about tuning and internal combustion engines not to mention how to spell.
From Genesis: "And God promised men that good and obedient wives would be found in all corners of the earth."
Then He made the earth round...and He laughed and laughed and laughed!
|
|
|
Re: Merc XR-6 150 Preformance
[Re: militarybrat]
#12362538
07/28/17 04:09 PM
|
Joined: Jun 2011
Posts: 2,733
militarybrat
OP
Extreme Angler
|
|
OP
Extreme Angler
Joined: Jun 2011
Posts: 2,733 |
This is an internet forum not english class. The piston in an internal combustion engine uses the intake charge to quench (cool) the top of the piston so that it does not melt. Any carbon deposit on top of piston causes hot spots. With lower octane fuel ignites prematurely also known as detonation (pre ignition) This is a major cause of melting a hole in the piston. Keeping the engine clean along with running higher octane prevents this.
Now on to tuning in race engines it is very important for carbs to be tuned properly as they run on the ragged edge of their capability. Too lean then boom they explode,too rich no power proper jet selection is very important. The only reason for me to change jets in my outboard would be altitude as it is not a race motor with no mods. I can get into the weeds about how carbs work if you would like... Fuel injection is a different animal modern injection is controled by a computer. You must size your injectors to your build and program accordingly. I can get into the weeds here too if you like.
Who ever said nothing in life is impossible.
Never tried slamming a revolving door.
|
|
Moderated by banker-always fishing, chickenman, Derek 🐝, Duck_Hunter, Fish Killer, J-2, Jacob, Jons3825, JustWingem, Nocona Brian, Toon-Troller, Uncle Zeek, Weekender1
|
