Who cares what the valves look like on their seats. You should try and get a shot of the blockage, or lack there-of, on the backside of the intake valve in the port. If any cleaning really takes place (and if the intake valve is actually loaded with gummy crud), that's where it'll be noticeable
Fuel power put to the test - pictures!
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I have a "shock" dose of FP in my 7 HP B&S generator engine. In one tank of running it, the smell of the exhaust changed noticeably. It no longer has that characteristic "old Briggs" smell to it, but it emitted no smoke whatsoever. It never did, no matter how old and stale the fuel in the tank was. This thing has started on the very first pull even with fuel that has been sitting in the tank for well over a year's time out in the shed.
Interestingly, the spark plug that came factory installed in this engine (it's a '74 model with point igniton...Pre-Magnetron) was a Champion XJ8. Now Champion is calling for a RJ19LM which looks to be considerably hotter, but tends to run much blacker than the plug that came in it to begin with. No idea why this is happening.
This generator has very little hours on it. Maybe 100 tops. It only gets used when the power goes out, and that's maybe an hour or two every couple years. Longest it ever ran was a few years ago when some tornados knocked out the power for 2 days. It ran steady for 3 hours at a time which was the time it took to run a tankful of gas thru it. It would get refilled and restarted immediately so I'd consider it running steady for over 48 hours.
It runs so good that I don't want to needlessly tear it apart, otherwise I'd do some before and after pics too.
Interestingly, the spark plug that came factory installed in this engine (it's a '74 model with point igniton...Pre-Magnetron) was a Champion XJ8. Now Champion is calling for a RJ19LM which looks to be considerably hotter, but tends to run much blacker than the plug that came in it to begin with. No idea why this is happening.
This generator has very little hours on it. Maybe 100 tops. It only gets used when the power goes out, and that's maybe an hour or two every couple years. Longest it ever ran was a few years ago when some tornados knocked out the power for 2 days. It ran steady for 3 hours at a time which was the time it took to run a tankful of gas thru it. It would get refilled and restarted immediately so I'd consider it running steady for over 48 hours.
It runs so good that I don't want to needlessly tear it apart, otherwise I'd do some before and after pics too.
ZmOz,
Your exhaust valve is getting white due to running leaner. You mentioned swapping carbs. I'm almost positive that's why this is happening. When combustion temperatures rise, the exhaust valves will get hot enough to burn off all the carbon, but it looks like there may be a little lead deposits perhaps on the valve. Just a guess, though I have seen the tops of the exhaust valves look like this in fairly new engines that have never seen leaded gas.
I used to work as a small engine mechanic back in the day, and still dabble with them a bit.
Your exhaust valve is getting white due to running leaner. You mentioned swapping carbs. I'm almost positive that's why this is happening. When combustion temperatures rise, the exhaust valves will get hot enough to burn off all the carbon, but it looks like there may be a little lead deposits perhaps on the valve. Just a guess, though I have seen the tops of the exhaust valves look like this in fairly new engines that have never seen leaded gas.
I used to work as a small engine mechanic back in the day, and still dabble with them a bit.
First of all, I'd like to apoligize for not replying the last few days, as I have not been allowed to post.
It has been raining almost non stop, so I haven't gotten past 7 hours, but will be continuing this test at least for a little while longer.
Are you referring to the white valve on the bottom? That's the intake valve - I mis posted above calling it the exhaust valve. I don't think I would call it cleaner, just changing colors. If you look at the first pic, there is still some *almost* clean metal on that valve. That area is now covered by the white deposits.
If you're talking about the top valve, in person I would say it looks almost the same as when I started, *maybe* slightly dirtier.
As for the plug, (and the entire engine) it looks that way because I ran this engine on about 40:1 10w30 mix prior to this test, so that I could get more carbon buildup. I left the dirty plug in rather than replacing it because I wanted to see if it would get cleaned. It also appears mostly unchanged to me.
I have not checked the compression, I don't have a compression tester.
Now, everyone here needs to understand that the ONLY reason I'm doing this test is so that I can see for myself how well FP does or doesn't work. I just thought everyone would like to see the pics. I never claimed it to be scientific and exact, but like I said, a dirty engine is a dirty engine.
And, I'd like to ask everyone else, what could possibly be wrong in an engine that only one tank of FP would make it run better? That's only 0.15 ounces of FP run through the engine at the shock dosage.
Once again, I never said I expected that. It should, however, gradually be getting cleaner, right? It's not. It's getting dirtier.
No, I am not using a new headgasket. I did install a new one at the beginning of this test, and it still looks like new.
Are you referring to the white valve on the bottom? That's the intake valve - I mis posted above calling it the exhaust valve. I don't think I would call it cleaner, just changing colors. If you look at the first pic, there is still some *almost* clean metal on that valve. That area is now covered by the white deposits.
If you're talking about the top valve, in person I would say it looks almost the same as when I started, *maybe* slightly dirtier.
As for the plug, (and the entire engine) it looks that way because I ran this engine on about 40:1 10w30 mix prior to this test, so that I could get more carbon buildup. I left the dirty plug in rather than replacing it because I wanted to see if it would get cleaned. It also appears mostly unchanged to me.
I have not checked the compression, I don't have a compression tester.
The engine is an '84 vintage, I don't know how many hours are on it. It is definately well used, but it was also maintained pretty well. When I got it, it had a stuck valve and I completely cleaned the head/combustion chamber. Then I decided to do this test on this engine, so I made it dirty again. So...the carbon has been there for about 2 months.
I'll try to get a pic of that next time.
There's definately no lead in this engine. If it is in fact running lean, that should only help FP do it's job.
Now, everyone here needs to understand that the ONLY reason I'm doing this test is so that I can see for myself how well FP does or doesn't work. I just thought everyone would like to see the pics. I never claimed it to be scientific and exact, but like I said, a dirty engine is a dirty engine.
And, I'd like to ask everyone else, what could possibly be wrong in an engine that only one tank of FP would make it run better? That's only 0.15 ounces of FP run through the engine at the shock dosage.
You were right the first time. That is the exhaust valve, not the intake valve that's getting whiter. The intake valve is always the larger one, and if you look closely in your first pic, you can see the muffler screwed into the side of the block by this valve, where the intake manifold on the top of the block (that metal tube) is near the larger intake valve.
This also leads me to believe this is a vertical shaft engine by the design of the intake. My guess is a Briggs model 92000 with a Pulsa-Jet carb.
I'm not sure that is correct. At a minimum, the lean condition means less Fuel Power. The leanness also means hotter combustion temps, so you may be tending to encrust the carbon, which incidentally by your own admission, is far above the range the engine would generate under any natural or defective condition.
In fact, I suspect your artificially created test parameters re the carbon are so far from what would be considered real world that they have made the "test" meaningless. I don't know if head design for 2-strokes is intended to address carbon buildup but you can be pretty sure the design of your B&S does not, at least not to the degree you have induced it.
[ October 26, 2004, 02:57 PM: Message edited by: TooManyWheels ]
First of all, I don't belive the engine is running lean. The carb that is on it is nearly brand new and runs absolutely perfectly on the lawnmower I barrowed it from. There is absolutely no reason why it would be running lean. If it actually is running lean, (again, highly doubtful) it still should be slowly getting cleaner from the FP. Maybe slower than usual, but it still should gradually be getting cleaner. I am using the shock dose, which is triple the normal amount of FP. If it was running lean, it would still have more than the normal amount running through the engine.
Secondly, how I made the carbon is irrelivant. Carbon is carbon. As far as small engines go, this is a very small amount. A "real world" engine would have much more carbon. This is not a 2 cycle engine.
Zmoz, good simple test. Keep up the work regardless of the pro-FP crowd.
Maybe it'll work 10hours longer into the test, maybe it won't.
For those of you who complained or tried to shoot down Zmoz, why don't you test it yourself??? or complain about so-called other independent tests????
Maybe it'll work 10hours longer into the test, maybe it won't.
For those of you who complained or tried to shoot down Zmoz, why don't you test it yourself??? or complain about so-called other independent tests????
I have a feeling that if Zmoz only wanted comments from people that agreed with him and would tell him what a great job he was doing no matter what, that he would have asked for the same. Or not posted at all
I would hope that anything anyone posts here gets some honest review. If it doesn't there is no reason for BITOG to exist.
If you have been around here a while, you should have noticed that any test result posted with strange looking results gets questioned. Sometimes a bit bluntly.
What's the point in participating here if you can't learn something? That goes for the postee and the poster.
Yes, I knew once I started posting pictures with bad results at least some FP users would come up with some excuses. Like I said, I am doing this test for me and me alone. You make a great point, XS650, if you don't like my test feel free to do your own and prove me wrong. In fact, I would LOVE for someone to prove me wrong, because I really do want this stuff to work as claimed.
What do you guys think about putting some FP down the carb while it's running? Or maybe something like a 50/50 FP/gasoline mix?
What do you guys think about putting some FP down the carb while it's running? Or maybe something like a 50/50 FP/gasoline mix?
The Scientific Method: Observation, Hypothesis, Testing.
"Of all the steps in the scientific method, the one that truly separates science from other disciplines is the process of experimentation. In order to prove, or disprove, a hypothesis, a scientist will design an experiment to test the theory. An important aspect of scientific experimentation is repeatability. In other words, if two different people in two different parts of the world perform the same experiment, they should both get the same results."
Keep at it ZmOz.
"Of all the steps in the scientific method, the one that truly separates science from other disciplines is the process of experimentation. In order to prove, or disprove, a hypothesis, a scientist will design an experiment to test the theory. An important aspect of scientific experimentation is repeatability. In other words, if two different people in two different parts of the world perform the same experiment, they should both get the same results."
Keep at it ZmOz.
Hey OZ, how ya holding up, great test you are doing. I have to agree with ya on the test you are doing about the engine getting dirtier. I think also there should be a bit of cleaning going on by now, and not more deposits.
I have done the same thing you have done with my Merc 150. It had Quicksilver in it for most of it`s life prior to me having it, and no matter what I did using the Quicksilver oil, it would have flaky carbon deposits in no time at all on the head and the plugs. I switched to Amsoil HP Injector, and the heads and the spark plugs are allways spotless now. I also should have taken some before and after pictures. The cylinders are nice and clean now also.
I have done the same thing you have done with my Merc 150. It had Quicksilver in it for most of it`s life prior to me having it, and no matter what I did using the Quicksilver oil, it would have flaky carbon deposits in no time at all on the head and the plugs. I switched to Amsoil HP Injector, and the heads and the spark plugs are allways spotless now. I also should have taken some before and after pictures. The cylinders are nice and clean now also.
I read in another site that a good way of removing carbon built up from the combustion chamber is by slowly spraying some water/ATF inside the throttle body. The claim is that it will create a mini shock wave that will loosen up carbon built up. Not sure if that is safe or not but maybe it worth a shot just for comparison purposes.
It's not just a flathead problem, it's Briggs problem. Years back I used a 3.5hp Briggs to mow a lawn I had. Later for the same yard I bought a 3.5hp Honda. The Honda took about 1/2 the fuel to do the same yard.
Back on topic, I wonder if using FP in this engine is a good test? Between the combustion inefficency of the Briggs and their carbs which are about as precise as drip feed, I'm not sure what anyone could expect to happen.
I'm not a cheerleader for FP, but not really a skeptic about it either. I'm using it in 3 vehicles now and so far the only thing I've noticed is a quieter fuel pump in my Mustang. I'm not saying it doesn't work, only that I'm not sure I'd have any way to tell without constant dissasembly of something that's known to be in good repair and well designed in the first place.
But, if it helps keep the fuel system clean it's good enough for me since the cost is reasonable compared to running something like Techron every few 1000 miles...
[ October 28, 2004, 11:13 PM: Message edited by: jsharp ]
For those that think Briggs engines suck I have one word for you all:
Tecumseh
Own a couple of those piles of crap and you'll be begging for a Briggs in no time.
That's the one thing I dislike about my little Ariens ST 2+2 snowblower...That POS oil drinking, smoky, rattly little Tecumseh H30.
It's a torquey little devil, but the quality of these engines is laughable at best.
I also have a Troy Built rototiller with a new Tecumseh 4 HP OHV engine on it and that too sucks the fat one. Emissions friendly tamper proof carburetor runs so lean that you have to let it warm up about 10 minutes before you can put load on it. I was told by the dealer that it'll get better as it breaks in. So far that hasn't happened. I think I'm going to wait till the warranty expires then just re-jet the carb one jet size bigger. That should fix it.
Tecumseh
Own a couple of those piles of crap and you'll be begging for a Briggs in no time.
That's the one thing I dislike about my little Ariens ST 2+2 snowblower...That POS oil drinking, smoky, rattly little Tecumseh H30.
It's a torquey little devil, but the quality of these engines is laughable at best.
I also have a Troy Built rototiller with a new Tecumseh 4 HP OHV engine on it and that too sucks the fat one. Emissions friendly tamper proof carburetor runs so lean that you have to let it warm up about 10 minutes before you can put load on it. I was told by the dealer that it'll get better as it breaks in. So far that hasn't happened. I think I'm going to wait till the warranty expires then just re-jet the carb one jet size bigger. That should fix it.
I agree Tecumseh's are bad, but Briggs are right up their.
Honda, Kohler and Kawasaki make some good engines. Kohlers 8hp flathead has to be one of the best running flatheads ever made. Kawasaki and Honda's OHV valve engine were great.
We took an 8HP Tecumseh off a Troy-built and installed a used 5.5 Honda. I had enough power for anything and started on the first pull every time.
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