What do you feed your engine???

[pfrederi 18,035]

Cleaned up the Tecumseh HH10 and figured out what happened.  I guess she got a new head at some point as there is no way the original head survived unmarked.  Bottom line DO NOT FEED your engine Choke plate or throttle butterfly screws.

 

Not so obvious what happened to the Kohler  head that marked it but left the piston unscathed.

 

[ztnoo 2,298]

The piston is the hammer, and the head is the anvil.

Bang, bang!!!

 

[C-101plowerpower 1,606]

right, don't feed your engine anyhing metal. 

what i dont get is this whole aditive's ethanol free gas thing

they've been slowly adding more and more alcohol( alcohol does great under boost) to our gas and no one bats an eye. well every once in a while we get a tank that didnt do as great as the others. 

how ever i do not get the problems you guys state side get, must be something in the gas one might say, but, how many of you put more than 95 octane in? even if straight gas is less would you still put it in?

 

 

im interested in the lowest octane people have reliably used in their horse

Edited September 17, 2017 by C-101plowerpower

[Jerry77 1,218]

18 hours ago, GREYGHOST said:

Then he calls me and tells me that the engine won't crank.

No good deed goes unpunished........

[gwest_ca-(File Mod) 11,148]

We have 87, 89 and 91 octane in Ontario Canada.

In most cases our 91 has no ethanol. 87 and 89 up to 10% ethanol.

Is there more than one way of measuring octane?

I use the 87 in Kohlers and B&S.

Use 91 in the 2-stroke engines because of the lack of ethanol. A new Stihl saw with what I suspect is throttle body injection hesitates bad on hot acceleration but since it is computerized they are trying to blame the fuel. Summer fuels are supposed to be blended to raise the vaporization point and just got more but the same. Heard this week that the refineries and starting the winter gasoline blend so my problem will likely get worse.

 

Garry

[Sarge 3,464]

Ethanol (made from corn) is highly corrosive - on carb equipped small engines it can literally eat the body and internal parts of the carb , rot the fuel lines , destroy the pump valves/body and leaves a nice white ash in the combustion chamber . No stock Kohler is over 9:1 that I know of , so literally 89 octane is overkill . I do run 91 non-ethanol Phillips 66 - never had an issue using that fuel and a little Sta-bil , have stored it over a year no problems . I've seen too many pistons with the tell tale signs of ingesting metal objects and it's common to see previous owners replace a cylinder head since it's so simple versus replacing the piston . Choke and throttle plate screws should always be staked properly - air cleaner screws should use proper lock washers or internal tooth locking washers so they can't rattle out . I've had it happen to 2 of my own engines from not replacing air cleaner screws when the locking washers are worn and flat - my own fault and I know better - lesson learned .

 

Sea Foam and some other products like it can help , if used in proper mix levels - exceed it too much and you can buy a new piston and valves . Honestly , none of that stuff is really necessary if you use good fuel to start with - I refuse to use corn ethanol in anything - even my 2014 Hemi that is designed to run it . Running ethanol in any older small engine will shorten it's potential life span - ask any reputable engine builder as they see the damage it causes every day . The Gov't and the manufacturers don't care - they build the engines well enough to exceed the warranty , after then it's your problem and it applies to any engine . The reasons for adding the stuff to fuel for the mass market can be argued to death , but in my opinion there is no good argument for it and the damage it causes over time costs us money . Now there is talk of pushing it to 15% or higher , that's pretty ignorant to me and unless the Public holds them accountable for the damage we're in for an expensive ride . Ask anyone that has ran the E85 for any length of time and see if they will admit to how many hours the vehicle spent in the shop...lol .

 

I have seen the piston damage mentioned earlier with no tell tale marks of a metal object being ingested into an engine . Two of my most trusted builders believe it is carbon deposits that have become hardened enough that , when they break loose from the valves/head they can cause that damage . I'm not totally sure , it could be the hotter side doing damage to the piston surface , carbon or some other unexplained issue but it does happen - odd as it is the only cure is to replace the piston . You'd have to know the full history first hand of the engine to have any sort of true idea of what caused it - such as how long was it ran before being de-carboned ...ect ??

 

Sarge

[stevasaurus 22,955]

I got a response from my engine guy.  He thinks, in both cases, something metal or carbon got in there and did the damage.  He also stated that the pitting was not like what he was talking about when I called him before.  So it looks like what Paul has is not from corrosion. 

[Skipper 1,789]

I have seen this many times also, and it is caused by a foreign object in the chamber. No doubt there. The corrosion pitting as you call it has much more organic shape. I would say a screw. If you look carefully, you can see a half moon imprint, and then it has bounced round and been slammed until compact enough to exit thru the exhaust.

 

On another note, I believe the pitting is much more a heat thing, than an ethanol thing. If it should be corrosion, I do believe the cast iron would be eaten long before the aluminium. Just from a physics point of view.

 

I remember back in the days with tuned mopeds etc. We saw this when running too lean on the mix, so it got too hot. 

Edited September 21, 2017 by Skipper

[elcamino/wheelhorse 9,358]

I run 89 octane  with 10 %  Ethanol  in everything and never had any problems with it messing up the motors. Maybe I don't use them as much as some of you guys. Pour some Sea Foam in the tanks about once a month and make sure filters are not clogged . I have replace all gas lines and filters every time I got a new  or other gas powered thing. Maybe I am just lucky on the Ethanol usage.

[Skipper 1,789]

4 minutes ago, elcamino/wheelhorse said:

I run 89 octane  with 10 %  Ethanol  in everything and never had any problems with it messing up the motors. Maybe I don't use them as much as some of you guys. Pour some Sea Foam in the tanks about once a month and make sure filters are not clogged . I have replace all gas lines and filters every time I got a new  or other gas powered thing. Maybe I am just lucky on the Ethanol usage.

 

The ethanol is particular bad if it has been left sitting for a long period of time. I think most know the green monster gunk it makes. But it eating anything, that I have never seen. However, it does wash the oil film away much more than the gas, but on the other hand it burns colder, so pros and cons i guess.

 

I'm not afraid of using it, but it pisses me off that it gunks up over time.

[pfrederi 18,035]

1 hour ago, stevasaurus said:

I got a response from my engine guy.  He thinks, in both cases, something metal or carbon got in there and did the damage.  He also stated that the pitting was not like what he was talking about when I called him before.  So it looks like what Paul has is not from corrosion. 

 

 

Steve Thank you for the research. 

Final answer seems to be the Tecumseh ingested screws from the carb.  Some previous owner noted a problem replaced the head and decided to live with the piston dents.

 

The Kohler is a bit more mystery.  The piston had no markings from damage and no size marking as if had been a replacement.  The piston and head are  both aluminum but different alloys.  Maybe the head is a bit softer  and the carbon dented it but not the piston.

 

Bottom line

 

#1 Do not feed your engine screws

 

#2 Clean out the carbon every 500 hours per Kohler service manual.

[stevasaurus 22,955]

Right Paul...he just made it clear from the pictures...it was not corrosion.  Maybe a broken off piece of ring is also something he mentioned.