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emtfire148186
06-06-2011, 10:57 PM
Trying to figure out why my exmark is burning oil. It has a horizontal kohler command sp27 with about 1460hrs. I do not have model or serial number. Is burning about a quart every other day. Fouls the plug on the number 1 cylinder. I have to use sandpaper to clean it. Its black wet deposits. It doesn't seem to have the power it use to have. The color of the smoke it a white to light blue. I run sunoco 93 octane.The following repairs were done

Both head gaskets
Both ignition coils
Stator coil
new cam
new lifters
fresh oil change (10-w30)
new air filter
new accelerator pump gasket
new plugs
sump gasket
hydro fluid change

Was told compression test and leak down test were good. Was told rings and cylinders were (OK) any help please...THANKS

groundsmechanic
06-07-2011, 10:30 AM
Kohlers have a history of burning oil but a quart every other day is excessive. If your breather system is plugged I believe it could cause excessive consumption. But with that many hours, I would lean toward the rings even though they "said" they were good.

Based on the work performed, I don't think they had the need to pull the pistons so how could they look at the rings to make sure they were good other than doing a compression and leak down test. If the numbers on the tests were just on the okay side of the minimum, I would still worry.

piston slapper
06-07-2011, 11:25 AM
Ive seen these engines routinely go over 3000 hrs.

Didnt see a REED VALVE on your list of replacement parts.
Bad reed uses alot of oil.

emtfire148186
06-07-2011, 12:30 PM
I will look into reed valve. Would reeds cause the #1 plug to foul? Is there a way to the cover off and see if its bad?

piston slapper
06-07-2011, 01:10 PM
A sticking or broken reed valve will pump oil into the carb thru the rubber hose that comes from the breather plate. It will foul 1 or both sparkplugs.


How recently was all the work you listed , done?

emtfire148186
06-07-2011, 01:18 PM
about 2 weeks ago the work was done, but has been burning oil just this season. Not sure if this was ok to do, but i took off the hose that goes into the carb from the breather with motor running and it has vacuum not pressure. lol not sure it that means anything.

piston slapper
06-07-2011, 02:24 PM
about 2 weeks ago the work was done, but has been burning oil just this season. Not sure if this was ok to do, but i took off the hose that goes into the carb from the breather with motor running and it has vacuum not pressure. lol not sure it that means anything.

Now let me get this straight.....

Work on engine....2 weeks ago....has been burning oil just this season...

So what you're telling me is that you did all this work and its still burning oil ?
You were already there...should have replaced the rings...compression rings may be OK , but your oil rings may be stuck or worn out.

I know thats not the answer you were looking for....
Replace the reed valve and breather plate gasket...
If the reed is not bent or broken, looks like the rings.

emtfire148186
06-07-2011, 02:53 PM
yeah go figure...lol... I will replace that this week. Just so im clear. Where are the compression rings? Where would oil rings be? sorry not the best at this. Can this be fixed or do i need a short block?

And yes all that work and still burning oil. I do notice small amounts of oil around the breather plate. I put my finger on the breather hose when its running and there is vacuum. Is that normal?

Thanks a lot

piston slapper
06-07-2011, 03:26 PM
The piston has 3 rings...the top 2 are for compression...the third is the oil control ring.
They are replaceable if the cylinder is ok ( see my avatar) (BTW..The pic is of a piston that broke at the oil ring land)

Get a 24 402 03-s reed valve and a 24 041 67-s breather plate gasket and replace them.
I've seen a few damaged reed valves....It would cause your problem.

Vacuum is normal on that hose....dont leave it disconnected

ricky86
06-07-2011, 08:23 PM
There is a good possibility that that the hd gskt is leaking. They have to be installed correctly, as in, by the book. There isn't much room for......... "That feels tight". The reed problem hasn't been any where as prevalent as it once was. It will pump oil into the intake tract. You have that condition?

emtfire148186
06-07-2011, 08:57 PM
I don't see any oil but just talked to the service guy said #1 cylinder was to scratched up to even worry about rings. So I'm beginning to think this is the problem but not sure. Also, said the leak down and compression test showed a slow leak on #1 cylinder, but the results were within spec. But he said the rings were still good. He also said the reed and gasket were good. Does it sound like time for a short block???
Thanks
Posted via Mobile Device

emtfire148186
06-08-2011, 12:08 AM
Don't think that is happening. Talked to the guy today and he said the #1 cylinder had bad gouges on it and wasn't worth doing rings. #1 cylinder also had a slow leak via the leak down test and low compression but he stated it was on the low side of the "OK" range. So i guess for now its a box of spark plugs and a few cases of oil lol. Does it sound like i need the short block of is this something that can be fixed? Thanks to all for your input

emtfire148186
06-08-2011, 12:11 AM
sorry for the 2 posts. sent the first one via cell and wasn't sure it posted

groundsmechanic
06-08-2011, 08:55 AM
Don't think that is happening. Talked to the guy today and he said the #1 cylinder had bad gouges on it and wasn't worth doing rings. #1 cylinder also had a slow leak via the leak down test and low compression but he stated it was on the low side of the "OK" range. So i guess for now its a box of spark plugs and a few cases of oil lol. Does it sound like i need the short block of is this something that can be fixed? Thanks to all for your input

It can be fixed but you will have to get .010" over pistons with .010" rings and have the cylinders redone .010" oversize. That should get rid of any wall issues unless they are really bad. It will correct the low compression and low leak down issues. But I don't know what the going rate is to oversize the cylinders.

piston slapper
06-08-2011, 12:43 PM
Don't think that is happening. Talked to the guy today and he said the #1 cylinder had bad gouges on it and wasn't worth doing rings. #1 cylinder also had a slow leak via the leak down test and low compression but he stated it was on the low side of the "OK" range. So i guess for now its a box of spark plugs and a few cases of oil lol. Does it sound like i need the short block of is this something that can be fixed? Thanks to all for your input

Kinda makes you wish he told you about the condition of the cylinder before you had all those repairs done.

Installing a fresh set of heads on a tired engine will only accelerate the oil usage. Sparkplugs and oil are probably you cheapest route.

emtfire148186
06-08-2011, 04:05 PM
Lol right. Hoping to get through this season like this. What's the ball park price for short block?
Posted via Mobile Device

ricky86
06-08-2011, 09:56 PM
$900.00. Run straight SAE 30 in it. It will help a little if it's a cylinder/ring problem. Won't do squat if it's a head gskt ( I get the impression you just don't want to believe this). Kohler claims it's OK in temps over 40-50 degrees.

emtfire148186
06-08-2011, 10:37 PM
i will switch to SAE 30. Willing to try anything right about now. How would i know if its a head gasket? There is no oil leaking anywhere on the tractor. Tests, from what i was told or in the low of ok range in number 1. Had same reading before and after new head gaskets. Thanks a lot

piston slapper
06-09-2011, 10:13 AM
$900.00. Run straight SAE 30 in it. It will help a little if it's a cylinder/ring problem. Won't do squat if it's a head gskt ( I get the impression you just don't want to believe this). Kohler claims it's OK in temps over 40-50 degrees.

Rick....You usually have good advice.....BUT...

I'm going to have to differ with you on this one.

If you run a straight weight oil (SAE30) in a Kohler Command engine, The lifters WILL PUMP UP AND THE VALVES WILL NOT CLOSE..
ENGINE STOPS RUNNING
PUSHRODS GET BENT
ROCKER STUDS RIP THE THREADS OUT OF THE HEADS
ETC.....ETC...ETC....


DONT ASK Emtfire to waste his engine...

SLAPPER

groundsmechanic
06-09-2011, 01:31 PM
Rick....You usually have good advice.....BUT...

I'm going to have to differ with you on this one.

If you run a straight weight oil (SAE30) in a Kohler Command engine, The lifters WILL PUMP UP AND THE VALVES WILL NOT CLOSE..
ENGINE STOPS RUNNING
PUSHRODS GET BENT
ROCKER STUDS RIP THE THREADS OUT OF THE HEADS
ETC.....ETC...ETC....


DONT ASK Emtfire to waste his engine...

SLAPPER

x2

All my Kohler books say 10w30 for normal temps and 5w30 for colder. No 30wt.

emtfire148186
06-09-2011, 02:08 PM
All i ran was kohler 10w30. I did a oil change a week ago and switched to mobile1 10w30 high miles. Seem to slow the burning down some. I changed reed and breather plate gasket last night. Check oil this morning and was just below full line. Checked it hour ago after mowing and was near the add line. Its better then it was before but still burning some oil. from what i can see it doesn't smoke just sitting there its when under a load. Thanks everyone for your help

ricky86
06-09-2011, 08:13 PM
It's Kohler's approval, not mine. I can prove my words, but I won't. If you don't attend regular service updates, your out of the loop. Things change. I would not have suggested it unless I was sure it would only help. I was leary of it also, but now have 3 customers out using it for summer use.

ricky86
06-09-2011, 08:34 PM
Changed my mind. Read it a learn. :)

emtfire148186
06-09-2011, 08:43 PM
i wasn't doubting your post. I was just saying that's what i did. Like i said im willing to try anything that might help before i put out $900. lol i put enough money out already. Its a good machine other then motor issue

ricky86
06-10-2011, 08:41 AM
I know. Other people were. I hope it helps

piston slapper
06-10-2011, 10:48 AM
It's Kohler's approval, not mine. I can prove my words, but I won't. If you don't attend regular service updates, your out of the loop. Things change. I would not have suggested it unless I was sure it would only help. I was leary of it also, but now have 3 customers out using it for summer use.

RICKY.....RICKY....RICKY...

You cant believe everything you read....
Kohler might have done some field tests, But, I guess they didnt check their sales data on pushrod kits and lifters. Maybe they did, and want to bump up sales.
In my own field tests over the last 10-15 yrs.....THAT DOG WONT HUNT
I havent missed a Kohler update since you were in kindergarden...To suggest that I am "out of the loop" to somehow discredit me, doesnt even deserve a response. As a Certified Kohler Expert Tech for over 10 yrs, and a Kohler Warranty Authorized Dealer , I would never allow the use of anything other than 10W30 in a Command engine. I've seen the damages that straight weight oils do to these engines and to peoples bank accounts. By Kohler simply stating that you can use SAE 30 in these engines is not magically going to make these well known issues dissapear.

Use your head...your inexperience is showing...
Some landscaper is going to read your post, and needlessly tear up his engine.
Never present the exception as the rule.
I guess the people who have been re-writing history books have now infiltrated Kohler,Wisconsin.

SLAPPER

The more things change, the more they stay the same.

VegetiveSteam
06-10-2011, 03:23 PM
RICKY.....RICKY....RICKY...

You cant believe everything you read....
Kohler might have done some field tests, But, I guess they didnt check their sales data on pushrod kits and lifters. Maybe they did, and want to bump up sales.
In my own field tests over the last 10-15 yrs.....THAT DOG WONT HUNT
I havent missed a Kohler update since you were in kindergarden...To suggest that I am "out of the loop" to somehow discredit me, doesnt even deserve a response. As a Certified Kohler Expert Tech for over 10 yrs, and a Kohler Warranty Authorized Dealer , I would never allow the use of anything other than 10W30 in a Command engine. I've seen the damages that straight weight oils do to these engines and to peoples bank accounts. By Kohler simply stating that you can use SAE 30 in these engines is not magically going to make these well known issues dissapear.

Use your head...your inexperience is showing...
Some landscaper is going to read your post, and needlessly tear up his engine.
Never present the exception as the rule.
I guess the people who have been re-writing history books have now infiltrated Kohler,Wisconsin.

SLAPPER

The more things change, the more they stay the same.

2008-2009 Kohler Update Seminar Book Page 3. "Kohler has given approval to use SAE-30 oil in engines that use hydraulic lifters if the ambient temperatures are above 50F." I haven't missed a Kohler Update since 1990 and am also a certified Expert Tech. I have had no issues using 30W above 50F.

piston slapper
06-10-2011, 04:26 PM
2008-2009 Kohler Update Seminar Book Page 3. "Kohler has given approval to use SAE-30 oil in engines that use hydraulic lifters if the ambient temperatures are above 50F." I haven't missed a Kohler Update since 1990 and am also a certified Expert Tech. I have had no issues using 30W above 50F.

You would if you worked on mowers in Florida....

I was at the update...and argued the point...
Most of the more than 50 techs in attendance agreed with me.

I have no issue with YOU using 30W in your customers eqpt...(They're your customers)

NOT IN MY SHOP....It would be a quick trip to the timeclock.

VegetiveSteam
06-10-2011, 05:31 PM
You would if you worked on mowers in Florida....

I was at the update...and argued the point...
Most of the more than 50 techs in attendance agreed with me.

I have no issue with YOU using 30W in your customers eqpt...(They're your customers)

NOT IN MY SHOP....It would be a quick trip to the timeclock.

If I were in Florida I'd never use anything but 30W. It's the cooler temps that would cause a problem. Not the warmer.

piston slapper
06-10-2011, 05:46 PM
If I were in Florida I'd never use anything but 30W. It's the cooler temps that would cause a problem. Not the warmer.

The problem is the lifters that pump up (clog) with any oil thicker than 10W30.
Its all about the viscosity.

We're just going to have to agree to disagree.

PARTS DONT LIE...PEOPLE DO...

VegetiveSteam
06-10-2011, 05:48 PM
We're just going to have to agree to disagree.

PARTS DONT LIE...PEOPLE DO...[/QUOTE]

I agree *trucewhiteflag*

VegetiveSteam
06-10-2011, 05:51 PM
Trying to figure out why my exmark is burning oil. It has a horizontal kohler command sp27 with about 1460hrs. I do not have model or serial number. Is burning about a quart every other day. Fouls the plug on the number 1 cylinder. I have to use sandpaper to clean it. Its black wet deposits. It doesn't seem to have the power it use to have. The color of the smoke it a white to light blue. I run sunoco 93 octane.The following repairs were done

Both head gaskets
Both ignition coils
Stator coil
new cam
new lifters
fresh oil change (10-w30)
new air filter
new accelerator pump gasket
new plugs
sump gasket
hydro fluid change

Was told compression test and leak down test were good. Was told rings and cylinders were (OK) any help please...THANKS

Ok I'm being a bit lazy here. I haven't read all the posts connected with your question and maybe this has already been posted but I would look toward a head gasket.

ricky86
06-10-2011, 10:13 PM
Slapper are you a republican by any chance?(lol) Experience is the best teacher, which you MUST lack. Maybe your skills aren't up the modern standards, being so old and everything. Get a repair manual and have someone read it to you. I will agree the lifters clog. But not from SAE 30. They clog from infrequent oil changes. Kohler had the geometry all wrong on the valve train. They fixed that. I'm right and your very wrong. Accept it and move on.

Restrorob
06-10-2011, 10:38 PM
Kohler had the geometry all wrong on the valve train. They fixed that.


Ricky, Tell us in your own words what Kohler did to fix their valve train problems that has existed since day one.

Snyder's Lawn Inc
06-10-2011, 10:43 PM
It's Kohler's approval, not mine. I can prove my words, but I won't. If you don't attend regular service updates, your out of the loop. Things change. I would not have suggested it unless I was sure it would only help. I was leary of it also, but now have 3 customers out using it for summer use.

Once the temps are up I run 30w in all my mowersI done it for yrs Cool weather run 10w30

ricky86
06-10-2011, 11:08 PM
Changed heads to accept revised rocker design, reduced the amount of parts, upgrade push rods, changed lifter design(2x). Vendor change for lifter I believe twice. New cam lube for break-in during initial start-up. They recommend 15 min run in at igle for cam break in. Did I miss anything? Understand were this thread started. An old engine on borrowed time that probably shouldn't have been repaired in the first place. During the summer, it won't hurt. Sounds like the valve train is the least of the problems. And anyone who would have done all that work with cylinders in such questionable condition is a crook and a hack. So most likely that motor is doomed anyway.

emtfire148186
06-10-2011, 11:16 PM
Yeah the heads were done. Ill just look into the short block. Will be easier then to keep on guessing and handing out money...lol....

VegetiveSteam
06-10-2011, 11:42 PM
Slapper are you a republican by any chance?(lol) Experience is the best teacher, which you MUST lack. Maybe your skills aren't up the modern standards, being so old and everything. Get a repair manual and have someone read it to you. I will agree the lifters clog. But not from SAE 30. They clog from infrequent oil changes. Kohler had the geometry all wrong on the valve train. They fixed that. I'm right and your very wrong. Accept it and move on.

Easy there Ricky. This republican was agreeing with you.

ricky86
06-11-2011, 02:58 AM
Easy there Ricky. This republican was agreeing with you.

Sorry, lost my head for a moment. :)

piston slapper
06-11-2011, 10:48 AM
Ricky...Ricky...Ricky....
Lets not get political....This is a family based forum...
You seem to mock all the wisdom and experience you claim to possess.
It sounds like you learned all the lies about lifter problems really well.
You might make a good USED CAR SALESMAN someday, maybe.
A mechanic that knows it all is a fool. If you had done your homework, you would know that the lifter problems happen when the oil is thick...Dirty 10W30 or fresh SAE30....
Thats twice that you chose to trash my technical and mechanical Expertice rather than addressing the problem at hand. You cut and run really well (accuse your accuser)
Keep up the jibberish...Then all who visit this post will see your ignorance......


VegetiveSteam.....20 yrs Kohler experience ?????
The first item on the repair listed was the head gaskets...
The repairman admitted that the #1 cylinder was scratched up beyond re-ringing
With all your knowledge you figured the head gasket is the problem ?
Have you been inhaling too much carb cleaner ? How did you ever pass the Kohler Test?
I knew this would happen when they started taking the test online, instead of taking it on paper, in person , with no reference materials.....Who took your test for you????

YOU MIGHT WANT TO CHECK THE PEDIGREE OF THE DOG BEFORE YOU YANK THE CHAIN

SLAPPER

VegetiveSteam
06-11-2011, 12:01 PM
Trying to figure out why my exmark is burning oil. It has a horizontal kohler command sp27 with about 1460hrs. I do not have model or serial number. Is burning about a quart every other day. Fouls the plug on the number 1 cylinder. I have to use sandpaper to clean it. Its black wet deposits. It doesn't seem to have the power it use to have. The color of the smoke it a white to light blue. I run sunoco 93 octane.The following repairs were done

Both head gaskets
Both ignition coils
Stator coil
new cam
new lifters
fresh oil change (10-w30)
new air filter
new accelerator pump gasket
new plugs
sump gasket
hydro fluid change

Was told compression test and leak down test were good. Was told rings and cylinders were (OK) any help please...THANKS

Yep I admit I screwed up on this one. I did not read the complete post. The first few lines of the description screamed head gasket and I stopped there. I believe I even mentioned my laziness on this one in my post. But that being said the last line of the post says "rings and cylinders were (OK)." At least I admit when I'm wrong or more accurately lazy in this case. I'm not quite sure how this childish bickering is helping anyone with their problem but it's kind of fun. Ricky keep up the good work. We're still correct on the 30W oil no matter how much Slapper tries to insult us. We're professionals folks. Don't try this at home.

piston slapper
06-11-2011, 12:26 PM
Yep I admit I screwed up on this one. I did not read the complete post. The first few lines of the description screamed head gasket and I stopped there. I believe I even mentioned my laziness on this one in my post. But that being said the last line of the post says "rings and cylinders were (OK)." At least I admit when I'm wrong or more accurately lazy in this case. I'm not quite sure how this childish bickering is helping anyone with their problem but it's kind of fun. Ricky keep up the good work. We're still correct on the 30W oil no matter how much Slapper tries to insult us. We're professionals folks. Don't try this at home.

Been there...Did it....
Sorry about the Kohler test comment..

A little friendly debate can be a fun thing ....sometimes...
None of us are getting rich in this highly competitive business.
I'm sure Both of you guys are professionals...But somehow you got on the wrong side of my conversation.
This is the same thing that happened at the update school when Kohler hatched this egg (SAE30 in Command engines)

Using SAE30 in Command engines increases the probability of lifter problems.

I hate working Saturdays.....Time to call it a week and crank up the BBQ

SLAPPER

ricky86
06-11-2011, 01:15 PM
Yep I admit I screwed up on this one. I did not read the complete post. The first few lines of the description screamed head gasket and I stopped there. I believe I even mentioned my laziness on this one in my post. But that being said the last line of the post says "rings and cylinders were (OK)." At least I admit when I'm wrong or more accurately lazy in this case. I'm not quite sure how this childish bickering is helping anyone with their problem but it's kind of fun. Ricky keep up the good work. We're still correct on the 30W oil no matter how much Slapper tries to insult us. We're professionals folks. Don't try this at home.

I agree. Time to move on.

emtfire148186
06-11-2011, 01:19 PM
When i 1st posted my original comment, that is what i was told. ring and piston were ok. Them when i talked to the shop, couple days later i was told the #1 was no good. Wish i would have known this before the work i would have held off. Thanks guys for the help.

ricky86
06-11-2011, 01:28 PM
Wow, I think every body forgot about you. Sorry everyone went off on rants. There is no fix for worn/damaged cylinders short of extensive/expensive repairs.

VegetiveSteam
06-11-2011, 01:33 PM
Been there...Did it....
Using SAE30 in Command engines increases the probability of lifter problems.


I don't disagree with this statement and I myself have seen bent push rods, broken rocker arms and rocker arm bolts pulled out of the head from what I blame on using SAE30. I just have never personally seen or come across what I believe to be an issue with SAE30 when used as Kohler recommends only above 50F. Do you remember when the Command first came out in what was it 90-91 Kohler's oil recommendation was 10W40. Actually these days I see very little issues with hydraulic lifters and most of the issues that I saw years ago were on vertical twins and that was just noise. After Kohler made the change to the block in April of 2001 that issue was gone. There were some issues on horizontal twins when the oil pick up tube o-ring wasn't seated correctly and let it suck air after Kohler made the change to the oil pump. Most of the problems I see with engines in general are user produced by lack of maintenance or abuse.

Well I think I'm going to go chase a golf ball around.

Enjoy the bbq and the rest of the weekend.

Sharpcut 1
06-11-2011, 03:40 PM
As a Kohler Expert dealer, I gotta agree with Piston slapper. I would never let a teck or customer put straight 30 in a command. Wanna hear the lifters tick?? Ever install a Kohler lifter that was'nt bled down, what happened??:nono:

That being said, with almost 1500 hours, and scratches in the no 1 cylinder, I would of never of let my customer rebuild the top end of this engine. If it got hot enough to warp the heads, the cylinder is always gonna be suspect of being overheated. Don't get me wrong, I have a mill in my shop, and we have cut our fair share of Kohler heads, usually about .005 to clean them up after warpage, which is almost always where the exhaust port is on the head.

To the original poster. check your invoice, see if the new head gasket kit was used , or the old. The new kit part # will end in 04, the old gasket 03. Did they replace the hardware that came with the head?? Does anyone know if this spec # has the chrome impregnated cylinders??

In my opinion, short block it and be done with it. The shop that rebuilt the top end should at least eat the labor on the original repair towards the shortblock. If the valve job was done correctly, the shortblock comes with the gasket kit and will be a matter of taking your top end, flywheel, coils, starter, stator, and shrouds and transfering them over to the shortblock. Only thing that sucks is that Kohler only gives a 90 wasrranty on a shortblock.

For those of you who think Kawasakis dont blow head gaskets, here you go:

emtfire148186
06-11-2011, 06:04 PM
yeah new gaskets and new hardware was used. I noticed it only smokes with blades en engaged. I found online that if you have bad spindle bearings it will make motor struggle more. Not sure if true or not, but without blades engaged i have all the power, but when running blades it struggles. also heard i heard if bearings in clutch were bad it also could cause this. I know it will not stop the burning of oil, but hoping it might slow it down. I do know i need spindle bearings. Looking into short block. But another problem. No model number or spec number on the motor. Tag was gone before i got it. All i know it a kohler command sp27. Any ideas where i can get the info to price new short block? Thanks a lot

VegetiveSteam
06-11-2011, 06:39 PM
[QUOTE=Sharpcut 1;4059872]As a Kohler Expert dealer, I gotta agree with Piston slapper. I would never let a teck or customer put straight 30 in a command. I guess my thought on the SAE30 would be this. If Kohler says it's ok who am I to argue with them? They know a lot more about it than I do. Like Slapper said. We will just have to agree to disagree.

Does anyone know if this spec # has the chrome impregnated cylinders?? I think you mean Nikasil and no it doesn't. That was only CH & CV 25s.

emtfire148186
06-21-2011, 09:21 PM
One last question. I have no power at all. Going up small inclines it will drop rpm big time. Sometimes having to shut blades off to make it up the hill. I have all the power in the world with blades off. Like i stated #1 cylinder is gouged and burning oil. Would this cause the lack of power?

DaveyBlue32
02-01-2012, 02:45 AM
Never run a full syn. oil in a push rod engine or your older truck...it makes leaks. Put an ethanol treatment in every tank for all 2 and 4 stroke engines...it burns hotter and retains water molecules that are released on combustion.... ie. in the cylinder, which breaks down oil viscosity which causes ware ...not good Moonshine is for drinkin' not running an engine!