How much MMO can I put in a Kohler 12hp engine?

[Bullet]

The engine is on a Gravely and had sat for about 3 years. I drained the bad gas out the thank and carborator bowl. Got it run, but it back fires. Even when it ran ok it back fired when reducing the engine speed. I'm thinking maybe there is build up on the valves.

It holds 2 quarts of oil. How much MMO can I put in the engine? What would be a good off the shelf fuel treatment?

I got this pic off google and this is the machine, just a lot older.

 

[SrDriver]

Max of 20% in the oil from reading on their web site or in other words when doing an oil change substitute the amount of oil that you would normally add with MMO. Do not overfill.

4 oz of MMO per 10 gallons of gasoline.

 

[Trav]

Its more likely to have junk in the carb jets than valve deposits.
Seeing as it does run, get some Berrymans chemtool and put 4-5oz in the tank and fill it with gas.
Run the engine about 10 min to get the stuff flowing through the carb and shut it off with the carb bowl full. Leave it a couple of days and try it.

 

[ABerns]

Yes, sounds like a fuel issue, not oil. I would put 0 MMO in my oil, and maybe a little Seafoam in the gas. Otherwise, just use it a lot - running a few tanks of fresh gas might make a world of difference.

 

[Donald]

Forget the MMO. Use blue Stabil max ratio on the label in the gas. Its got some great cleaners in addition to being a stabilizer.

 

[Slick17601]

Give it a valve job and be done with it. If the valves are varnished from old gas, all the chemicals in the world will not help and you run the risk of burning a valve seat while you're messing aroumd with them.

 

[demarpaint]

Originally Posted By: Trav
Its more likely to have junk in the carb jets than valve deposits.
Seeing as it does run, get some Berrymans chemtool and put 4-5oz in the tank and fill it with gas.
Run the engine about 10 min to get the stuff flowing through the carb and shut it off with the carb bowl full. Leave it a couple of days and try it.


+1 Once you sort it out dose the gas with MMO to keep the carb clean and working properly.

 

[Pop_Rivit]

Pull the carb and clean/fix it right-it will take all of an hour. Those little carbs are very simple, and you'll be much happier than trying to fix something with any sort of mystery oil, chemical treatment or other magic liquid.

 

[TFB1]

You can give it a valve job if you like, I'd be douching out the carb...

 

[clarklawnscape]

get some premium fuel, nearly fill it up, then top it off with a 1/4 bottle of seafoam, let it run and hope for the best

 

[Cmarti]

Originally Posted By: Pop_Rivit
Pull the carb and clean/fix it right-it will take all of an hour. Those little carbs are very simple, and you'll be much happier than trying to fix something with any sort of mystery oil, chemical treatment or other magic liquid.


+1, it is an hour with a beer to start and one at the end. Small carbs are easy.

 

[Bullet]

Thanks for the replies. While it did have bad gas, it wasn't run with bad gas. The battery died and that is why it sat up for a while. The engine always back fired when reducing the engine speed somtimes. Prior to sitting up it was ran several times a week. The machine is about 1.5 hours away at the MIL's property so I don't realy have the time for much in the way of repairs. I wanted to put it in the truck and bring it home, but it's so difficult to push I had to use the 4 wheeler to pull it out the shed. I'll try fuel treatment first and see it that helps.