85/86 250R oil mix ratio 20:1 or are you running something different?

[dbtiger]

I just picked up an 85 250R a few days ago. Previous owner said he was running 32:1 but I know the service manual calls for 20:1. What ratio are you running, and is there a rule of thumb if you deviate from 20:1.

[fabiodriven]

20:1 was for the oil available at the time your ATC was produced. You can still run that ratio with beanol or straight 30 weight oil, but modern two stroke oils are far superior and you mix it at a much lower ratio of oil. Some are 32:1, some 40:1, some 50:1. I run one bottle of Golden Spectro to five gallons of gas and that's all I've done since the 80's.

I rode with a guy last year (Sanchez) who was running 20:1 beanol. It stunk terribly and nobody could ride behind him.

[RoscoW]

Oil technology has come a long way in the last 30 years, most people run in the 32:1 to 50:1 range with a good quality modern oil. I personally run 50:1 Amsoil and have never had oil related issues. I always have a nice little pool of residual oil sitting in the crankcase upon teardown, and it's an easy mix for long trail rides if you have to get gas, I carry a 1 gal gas can with me and always have a couple little Stihl chainsaw oil bottles with me full of oil to mix at the gas station.

Ross..

[dbtiger]

20:1 was for the oil available at the time your ATC was produced. You can still run that ratio with beanol or straight 30 weight oil, but modern two stroke oils are far superior and you mix it at a much lower ratio of oil. Some are 32:1, some 40:1, some 50:1. I run one bottle of Golden Spectro to five gallons of gas and that's all I've done since the 80's.

I rode with a guy last year (Sanchez) who was running 20:1 beanol. It stunk terribly and nobody could ride behind him.
That’s good to hear. What are the brands with the best reputation? I can get the Lucas Oil semi-synthetic close to the house.

[dbtiger]

Oil technology has come a long way in the last 30 years, most people run in the 32:1 to 50:1 range with a good quality modern oil. I personally run 50:1 Amsoil and have never had oil related issues. I always have a nice little pool of residual oil sitting in the crankcase upon teardown, and it's an easy mix for long trail rides if you have to get gas, I carry a 1 gal gas can with me and always have a couple little Stihl chainsaw oil bottles with me full of oil to mix at the gas station.

Ross..
I like your idea using the small stihl bottles. I always have those lying around the garage.

[fabiodriven]

It's difficult to go wrong with Lucas anything.

[greenhaze20]

I stay with 20:1 and use royal purple. More oil more protection and your motor will last longer. You could use less and probably be fine. I also have a blue cloud of smoke every time I get on it. Would be nice to hear from other guys that run less oil if they still get smoke at WOT.



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[fabiodriven]

I stay with 20:1 and use royal purple. More oil more protection and your motor will last longer. You could use less and probably be fine. I also have a blue cloud of smoke every time I get on it. Would be nice to hear from other guys that run less oil if they still get smoke at WOT.



You're not really getting "more protection", you're just wasting oil and making smoke.

[Doug8765]

You're not really getting "more protection", you're just wasting oil and making smoke.

I had my engine builder tell me 20:1 i said why.. he said do you dyno these motors and then measure the piston / rings i said no. Then use 20:1


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[greenhaze20]

You're not really getting "more protection", you're just wasting oil and making smoke.

So less oil means more protection. Got it.


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[fabiodriven]

So less oil means more protection. Got it.


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No Einstein. Fuel cools, oil lubes. If you take away more fuel your engine could potentially run hotter, and heat is the enemy. But what do I know?

Run whatever you choose, it's your bike. Like I said from the beginning, you CAN run 20:1. What you and this other guy are not taking into account is that modern oils are not intended to run at 20:1. Sure they can, but you're sacrificing your own performance for a gain that very well might be overcome by the higher temperatures you might be making. If you want to spend your money on oil that you don't need to while simultaneously making your bike burble and smoke obnoxiously, and also plugging up your exhaust, go for it.

The entire point of modern oils is to burn as cleanly and efficiently as possible while offering you the best performance you can have. I've had two strokes last years and years and years, I don't think there's any longevity problems with using modern oils the way they've been intended.

[Arky-X]

I had my engine builder tell me 20:1 i said why.. he said do you dyno these motors and then measure the piston / rings i said no. Then use 20:1


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What oil is being used?
SAE 30W?
10W-30?
or some other old school oil?.......if so, then yes, run 20:1

[atc300r]

I run my 3 250rs and 300r on 32:1. with Amsoil dominator mixed with 91 non ethol gas.Amsoil,and some of the popular oils for 2 strokes have been around since the 70s.Klotz has been around for about 60 years.If you are using 86 octane gas with ethol go with 20:1.My local Honda Dealers back in the day recommended Castrol oil .Back in the 80s 2 of my uncles ran their 250rs on 84:1 with Amsoil they used the type that could be mixed at 100:1.They never had any issues and we rode every weekend.

[yaegerb]

I had my engine builder tell me 20:1 i said why.. he said do you dyno these motors and then measure the piston / rings i said no. Then use 20:1


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Get a new engine builder

[yaegerb]

What oil is being used?
SAE 30W?
10W-30?
or some other old school oil?.......if so, then yes, run 20:1

This doesn’t even make sense. When did we change the subject to 4 stroke oil?

[atc300r]

Also to much oil and it can get trapped between the rings and over heat and burst the rings.This post and my other post are my 2 cents.

[fabiodriven]

This doesn’t even make sense. When did we change the subject to 4 stroke oil?

In the 80's and earlier it was not uncommon for people to run straight 30 weight or 10w30 as pre-mix oil.

[ironchop]

I had my engine builder tell me 20:1 i said why.. he said do you dyno these motors and then measure the piston / rings i said no. Then use 20:1


Sent from my iPhone using Tapatalk ProThat's a generic non-answer. I hate when ppl say stuff like "because I said so"...tell him to cough up the facts. "Because I dyno stuff and you don't" doesn't mean he knows what he's talking about. Someone with real knowledge will explain why and unless he asked you what engine size/type , Make and model, fuel octane, style of riding, etc then he's probably already wrong with that generic answer.

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[Arky-X]

This doesn’t even make sense. When did we change the subject to 4 stroke oil?

Well ain't I the idiot?
I rode with 2 guys back in the day that had 2 strokes and one only used 30W in his 250R and I have no idea what the other used in his Quadzilla. I never questioned any of it because all I ever had was a 4 stroke.

Since the only 2 strokes I've ever owned are a chainsaw and a weedeater, I will just hang-up and listen on this thread. I will admit when I have a brainfart.

[ironchop]

No Einstein. Fuel cools, oil lubes. If you take away more fuel your engine could potentially run hotter, and heat is the enemy.
..

Yup more oil equals less gas. Less gas equals lean conditions. Lean conditions equals more heat.

The volume of fuel/oil moving thru your jets is constant at any given throttle opening unless you rejet but when you put more oil in the exact same volume, you end up with less gas in the same volume

That's why when you change premix ratios, you sometimes need to rejet



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[fabiodriven]

Well ain't I the idiot?
I rode with 2 guys back in the day that had 2 strokes and one only used 30W in his 250R and I have no idea what the other used in his Quadzilla. I never questioned any of it because all I ever had was a 4 stroke.

Since the only 2 strokes I've ever owned are a chainsaw and a weedeater, I will just hang-up and listen on this thread. I will admit when I have a brainfart.

No you're on point Arky. A lot of people were running motor oil as pre-mix back in the day, it's not at all unheard of.

[ironchop]

Yeah I've heard of ppl using 30W car oil back then as well but a service tech at our local yammy dealership when I was a teen told me not to because motor oil has particulates in it when it burns that gets leftover to help scratch and wear out rings and stuff. I've seen four strokes that burnt alot of oil looking like someone threw oily sand inside the cylinder and my valve stems were scratched too as well as the cylinder walls and piston. This has been the case more than once when I cracked open an unknown motor that burnt alot of oil. I'm not certain if that's what the case was but it was the one common denominator. No metal shavings in the oil but lots of oily carbon chunks everywhere in the cylinder

I'm not sure if he was full of crap or he just wanted me to buy more expensive Spectro from him but I bought the oil that was designed to burn instead (Spectro)

Maybe it's because Brendon is younger than us and so he only knows about the period after The Awakening, when we quit being cheap and lazy[emoji23]...that's why Arky's reply sounded like absolute gibberish to him. With today's premix oil tech, it is frowned upon to use car motor oil since we moved away from that thanks to education and better products. I'm sure no offense to Arky. Perhaps if he said 'WTF?!?!' instead

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[atc300r]

My dad always used 10w30 or 10w40 in his chainsaws both in the gas and for the bar.

[yaegerb]

In the 80's and earlier it was not uncommon for people to run straight 30 weight or 10w30 as pre-mix oil.

I have honestly never heard of this before. My aplogies to arky-x for the lack of insight.

[dbtiger]

I run my 3 250rs and 300r on 32:1. with Amsoil dominator mixed with 91 non ethol gas.Amsoil,and some of the popular oils for 2 strokes have been around since the 70s.Klotz has been around for about 60 years.If you are using 86 octane gas with ethol go with 20:1.My local Honda Dealers back in the day recommended Castrol oil .Back in the 80s 2 of my uncles ran their 250rs on 84:1 with Amsoil they used the type that could be mixed at 100:1.They never had any issues and we rode every weekend.im glad you mentioned octane and ethanol. Unfortunately, I can’t find ethanol free in metro St. Louis, and sometimes premium is only 89 octane.

[dbtiger]

Great discussion so far in this thread. Thanks for the feedback and keep it coming.

[Tri-Z 250]

Look for a Fuel distributor in your area...Home fuel Oil, Truck and Race fueling business. No corner gas station it's going to take some looking around. Next time you see a car show, stop in and ask some vintage car guys...bet there is a spot not far out of the way.
Take it for what it is: My motor builder Minton Cycles and I talked about this subject over my sons 16'CX65 which had a full respring/National Race Prep done on it. He said Cobra actually tested non eth to pump gas and fresh eth pump gas makes better compression in their machine with a full synthetic BelRay blend.

[fieldy]

im glad you mentioned octane and ethanol. Unfortunately, I can’t find ethanol free in metro St. Louis, and sometimes premium is only 89 octane.

The internet will give you local stations that sell ethanol free gas. Type in something like buy real gas. A guy i know thought that when he bought 93 oct it was ethanol free, boy was he surprised when he found out that it was ethanol gas.

[yaegerb]

My .02

This is IMO one of the better oil ratio excerpts written.
http://www.klemmvintage.com/oils.htm

If you want the cliff notes, oil ratio is a function of RPM. High, sustained revs require a larger ratio of oil to gas (20-25:1) whereas inconsistent RPMs or on average, lower RPM engines can get away with less oil to gas ratio (30-40:1).

IMO, Honda was playing it safe thinking that your everyday joe may/could be revving it to the moon during the life of the motor and they wanted to ensure the crank bearings stayed happy. This is a good thought but at 20:1 and as Fabio said earlier you are loosing a cooling effect because by its very nature gas is a coolant for your motor, moreso the higher in octane you go. So remember, more oil means less molecules of gas which equals less cooling for your motor. It’s all a delicate balance but goes right back to RPM.

If you are a sand duner or road racer, better start investing in (insert your favorite oil company here). If you are the weekend warrior on trails or just like to play around then 30-40:1 may be more your speed.

I cut the difference and run Klotz beanol at 36:1

[yaegerb]

im glad you mentioned octane and ethanol. Unfortunately, I can’t find ethanol free in metro St. Louis, and sometimes premium is only 89 octane.

Exxon at Clayton and Baxter in chesterfield sells 93 no ethanol, or at least they did when I lived there. You may want to check it out

[Rob Canadian]

I run my 3 250rs and 300r on 32:1. with Amsoil dominator mixed with 91 non ethol gas.Amsoil,and some of the popular oils for 2 strokes have been around since the 70s.Klotz has been around for about 60 years.If you are using 86 octane gas with ethol go with 20:1.My local Honda Dealers back in the day recommended Castrol oil .Back in the 80s 2 of my uncles ran their 250rs on 84:1 with Amsoil they used the type that could be mixed at 100:1.They never had any issues and we rode every weekend.

I worked at a Bosch Service center years ago. We were a Amsoil and Mobil 1 dealer. I remember the Amsoil stuff. 100:1. I thought to myself that is crazy. This was 1988-1993. Spot on with that info.

Interesting on the 10W30 info. I know I did mix some up in a pinch at the cottage years ago on my old 2 stroke dirtbike. It was all I had.

[Arky-X]

I have honestly never heard of this before. My aplogies to arky-x for the lack of insight.

No need for apologies. I really did have a brainfart remembering my buddy mix up his 30W and gas in a can for our rides. I never questioned it then because I didn't know any better. I use 2cycle oil for my chain saw and weed whacker but I wouldn't know the difference in it versus the Lucas, Amsoil, etc.

Didn't mean to derail the thread but...... motor oil is motor oil.......
https://m.youtube.com/watch?v=oLeXpF1kzDU

[Red Rider]

Back in the mid-late 80’s, my father was an Amsoil dealer, and kept trying to get my brother and I to try Amsoil, @ 100:1, in our 250R’s, but we didn’t trust it, so we never did. But when a trusted motorcycle service center owner, suggested we try HPS synthetic oil @ 100:1, we jumped all over it. Chalk it up to being young, and thinking dad didn’t know what he was talking about, I guess. We used HPS @ 100:1, with no issues in our ‘85-86 250R’s, and an ‘87 Tecate as well. When HPS went out of business, we switched to Redline synthetic @ 100:1, and still no issues. These days, the majority of our riding is sand dunes. After reading most of the oil ratio threads on this forum, usually with links to good articles by respected engine builders, I decided to richen up my mixture a bit. For the last 3 years now, I’ve been mixing my Redline @ 88:1, still no issues, nor noticeable gains.

[dbtiger]

Exxon at Clayton and Baxter in chesterfield sells 93 no ethanol, or at least they did when I lived there. You may want to check it outthats great to hear, I'll have to check them out. I’m in Wildwood, so Chesterfield isn’t that far from me.

[Doug8765]

What oil is being used?
SAE 30W?
10W-30?
or some other old school oil?.......if so, then yes, run 20:1

This was in 2004 told me to run maxima 927 castor at 20:1 syns been out since 70s guys!? This was one of the top shifter cart motor builders . I had him build me a cr 125 for 5000.00 complete. He has won several championships


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[Doug8765]

Get a new engine builder

[emoji1617]


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[dbtiger]

Back in the mid-late 80’s, my father was an Amsoil dealer, and kept trying to get my brother and I to try Amsoil, @ 100:1, in our 250R’s, but we didn’t trust it, so we never did. But when a trusted motorcycle service center owner, suggested we try HPS synthetic oil @ 100:1, we jumped all over it. Chalk it up to being young, and thinking dad didn’t know what he was talking about, I guess. We used HPS @ 100:1, with no issues in our ‘85-86 250R’s, and an ‘87 Tecate as well. When HPS went out of business, we switched to Redline synthetic @ 100:1, and still no issues. These days, the majority of our riding is sand dunes. After reading most of the oil ratio threads on this forum, usually with links to good articles by respected engine builders, I decided to richen up my mixture a bit. For the last 3 years now, I’ve been mixing my Redline @ 88:1, still no issues, nor noticeable gains.

Very interesting. If I ran into someone that told me to mix at 100:1/88:1, I’d think they had lost their mind and they would soon blow their engine. However, the fact that you have run these ratios for a long time, with no issues, gives some credence to running these ratios.

[Doug8765]

My .02

This is IMO one of the better oil ratio excerpts written.
http://www.klemmvintage.com/oils.htm

If you want the cliff notes, oil ratio is a function of RPM. High, sustained revs require a larger ratio of oil to gas (20-25:1) whereas inconsistent RPMs or on average, lower RPM engines can get away with less oil to gas ratio (30-40:1).

IMO, Honda was playing it safe thinking that your everyday joe may/could be revving it to the moon during the life of the motor and they wanted to ensure the crank bearings stayed happy. This is a good thought but at 20:1 and as Fabio said earlier you are loosing a cooling effect because by its very nature gas is a coolant for your motor, moreso the higher in octane you go. So remember, more oil means less molecules of gas which equals less cooling for your motor. It’s all a delicate balance but goes right back to RPM.

If you are a sand duner or road racer, better start investing in (insert your favorite oil company here). If you are the weekend warrior on trails or just like to play around then 30-40:1 may be more your speed.

I cut the difference and run Klotz beanol at 36:1

Tell fabaio to change jets more fuel to [emoji1617]


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[fabiodriven]

This was in 2004 told me to run maxima 927 castor at 20:1 syns been out since 70s guys!? This was one of the top shifter cart motor builders . I had him build me a cr 125 for 5000.00 complete. He has won several championships



If you'll notice, Doug, as was stated (possibly more than once), if you are running sustained WOT (such as shifter carts do), then 20:1 might be something you'd consider running. That was stated in this thread. So when you talk about ratios and engine builders in a thread about a Honda ATC250R three wheeler and reference information that pertains to shifter carts, you might want to open with something like "My friend who builds shifter cart engines, not ATC250R engines, says that 20:1 is the way to go when racing shifter carts, not when riding Honda ATC250R three wheelers."


Tell fabaio to change jets more fuel to [emoji1617]



Tell me yourself hunny.

So you're telling me you'd now jet fatter just to stick to your guns about running more oil which you don't need? You do realize that jetting is tuned individually to every engine, no two are exactly the same, correct? You jet to make the bike run right, not to be certain you can run an excessive amount of oil that you don't need.

By your logic Doug, I should completely forget about how my bike starts and runs, just throw that out the window, then jet it too rich so that I can run more oil.

The downside to running too much oil- waste of money, clogs exhaust, raises combustion chamber temperatures, chokes everyone behind me, fouls spark plugs, etc.

The upside to running too much oil- This is fill in the blank Doug. You tell me. You tell me why I should jet to compensate for running more oil than what's recommended by just about everyone including the oil manufacturers because I'm all ears my friend.

Poor Doug, wait until Glamy gets a load of this. I can see the memes now...

[ironchop]

Where's BarnettOU812?



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[HondaRidr]

This right here is the real deal haha. You beat me to posting this link. I've heard that something like 28 to 1 produces the max horsepower when someone experimented with different ratios on a dyno. I could be wrong about that though
My .02

This is IMO one of the better oil ratio excerpts written.
http://www.klemmvintage.com/oils.htm

If you want the cliff notes, oil ratio is a function of RPM. High, sustained revs require a larger ratio of oil to gas (20-25:1) whereas inconsistent RPMs or on average, lower RPM engines can get away with less oil to gas ratio (30-40:1).

IMO, Honda was playing it safe thinking that your everyday joe may/could be revving it to the moon during the life of the motor and they wanted to ensure the crank bearings stayed happy. This is a good thought but at 20:1 and as Fabio said earlier you are loosing a cooling effect because by its very nature gas is a coolant for your motor, moreso the higher in octane you go. So remember, more oil means less molecules of gas which equals less cooling for your motor. It’s all a delicate balance but goes right back to RPM.

If you are a sand duner or road racer, better start investing in (insert your favorite oil company here). If you are the weekend warrior on trails or just like to play around then 30-40:1 may be more your speed.

I cut the difference and run Klotz beanol at 36:1

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[Doug8765]

This right here is the real deal haha. You beat me to posting this link. I've heard that something like 28 to 1 produces the max horsepower when someone experimented with different ratios on a dyno. I could be wrong about that though

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Larger jet with more oil ! Runs same cause fuels thicker. You should change jets at least twice during the day from morning to night if you want it perfect favio[emoji851]


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[Outlaw #24]

dbtiger said he picked it up and the previous guy ran 32:1 ! Why change it? it was evidently working for him. Find out what oil he ran and start there until you know different. By changing the ratio or mixture you will be re-jetting the carburetor. Also when I started mixing for my 2 strokes, I used MC1+(Bell Ray), After I had the cylinder ported the first time, my engine guy told me to use Golden Spectro at 5gallons to 1 12oz bottle. That was in 88-89 and I have never used anything else, have never suffered from an engine failure caused from oil mixture. I have 1 cylinder, (I can Show you guys), that was run competively and riding and all for 28 years and still has the hone marks in the cylinder. Piston had a small crack in it and that is why I changed cylinders only,(Skeletor), Golden spectral has been around for a very long time and there formula has always remained the same when others like Blenzol or Klotz has changed formulas. the fuel does cool you engine while the oil lubricates everything and should not burn out it should lubricate all of the way through, from the Carb inlet to the exhaust Outlet it is to be lubricating. Use what ever oils mix you want as long as it works for you I do not give a rip. The gas you use has a significant effect on the performance of the engine. It indeed used to propel ass well as cool. Lower Octane fuels burn hotter. 92 octane is better than 89 octane, but if you want to get the most out of the engine, 110 is the easiest to work with. Get it from you local race shop or ask them where to get it. It is usually about 7 bucks a gallon but if you want to play, you got to pay! Todays technology dictates that we use something different that 30w SAE. In a pinch is 1 thing running all the time? I don't think so! BTW most of the oils we use to mix in our gas for our wheelers will not run that well in a chain saw or weed wacker and if you look on the bottle like HR1 it says it is not recommended for these engines. 1 more thing ENGINE (internal combustion), MOTOR (electric). Don't go there either! I love the idea of the chain saw oil bottle too! You guys are good

[dbtiger]

This thread has been educational for me. Obviously there’s not a consensus, but that’s ok...it makes for hearing good arguments on both sides of the issue.

The last time I owned a two stroke, it was 1987 and the 2 cycle oil I used was Bel Ray bought at the local Honda dealer. I mixed it to the manufacturer specs and rode on. Very interesting to learn about the advances in oil chemistry/technology and the effects on mixing ratios.

[Rhino-1]

Castor 927 at 40:1 for as long as I can remember (Banshees and Blasters since the mid-90's, an now on 250R's). Love the smell, the smoke is manageable, and the only issues I've had have been from rider-induced errors.... :beer

[efhondakid]

Klotz Beanol at 44:1 in my 250r in my YZ250 in my weed eater pretty much everything