2 stroke fuel mixture

[Lozza]

The problem I have with the phrase "I've never had any problem with using ....." is it accounts for 3 parts of SFA.These are just observations from one person's experience. As Doc's aftermarket head test proved facts and figures tend to mess up a good story.I  challenge anyone to repeat the tests outlined below with 30, 40 or 50:1.Anyone willing? Synthetics will perform better in Falex Pin and V Block tests but thats about all, after the film breaks down it wears parts much worse.

http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

Remember long after I'm gone someone will still be quoting Gordon Jenning's, with good reason.

[cxs58]

Lozza....are you saying that older bikes should use mineral oils and not synthetic ones....I have just bought Motul Off road 800 Factory Line synthetic oil....is this not a good idea....ah
Craig

[vandy010]

as far as synthetics go, here's my take on them,
a while back i had a very indepth convo with a bloke that worked in an oil sampling laboritory and he had several bikes both old and new. i mentioned to him i was using one of the new synthetics and asked for his opinion and he went on to say, as far as impurities on a PPM {parts per million} goes, the synthetic is cleaner, but not by as much as they'd have you think. he recommended good old valvoline xld for use in my gearbox, cheap as, and i can pick it up while i'm in
k-mart with the kids. so took his advice i did, have been running valvoline xld in all my gearboxes,mower,car and have never had a problem. cheap, being the big factor for me.
ok, thats gearbox's, but it is kinda synthetic 'V' mineral related.

and Freaky, the only reason i'm contemplating going richer is to prolong engine life. not that i have a problem with it all now but as the number of running engines increases, the less i want to be rebuilding something. so once it's together, i'd like it to stay that way for a long time.

[cxs58]

Vandy010....I too know people who work for the fuel industry....Caltex refinery up here in Brisbane....one bloke in particular backs up your comments....a cheap oil replaced often is better than an expensive oil changed infrequently....its all about cleanliness in the motor and gearbox....regular oil changes mean longer life.

Yes synthetic oils are cleaner than mineral based oils but not as much as the fuel industry lead us to believe.

My Huskys' piston is brand new so I have decided to use the 40:1 ratio....only reason is that I don't know any different and this is my first 2 stroke....if I register lots of slow lap times I can blame the oil fuel ratio....not my riding ability.

Thanks lads - see ya the race....!

Craig

[vandy010]

if your talking about nudgee tomorrow, i'll come and say g'day. if your the bloke i'm thinking of, had a bit of a high-side moment at the nudgee sign on day? i was right behind you when it happened, very impressive!
cheers mate!

[LWC82PE]

For me I’ts 20 to 1 or what ever the owners manual recommends. Preferably a mineral oil and definitly not synthetic for running in. You gotta remember these vintage bikes are mostly old air cooled motors and are not watercooled. Most of the synthetics have modern water cooled engines in mind. If you talk to anyone whos into ultra light air craft especially in north america and the only oil they trust to keep them up in the air is a mineral Penzoil 2 stroke oil specifically for air cooled engines and you wont hear them using 30, 40, 50 to 1 etc. Unfortunately this oil is not available in Australia.

And its not just Jennings whos against lean ratios. Graham Bell rams it into your head that more oil equals more power, less heat, less wear, longer life etc

So far out of all the people I hear from that use leaner ratios the main reasons I get are

I want to use less oil to save money
My bike smokes less with less oil
I pulled my motor apart and everything seemed to be ok with 40 to 1 so why should I change?
Or everyone else is using less oil so it must be the thing to do these days.

Sorry but I’m with Lozza and the other guys, you wont ever catch me using less oil.

If are going to change the ratio to something other than the owners manual remember you must then alter your jetting. Sound too hard to do, well then don’t change the oil/fuel mix ratio and then you wont have to stuff around with jetting.

Oh one other thing, octane booster definitely works.

[oldfart]

20 to 1 in all my 2 smokers . In the 70s and 80s I used Penzoil - now its Motul 800
My reseason - this is what the factory tested them at, and that was good enough for me 

[cxs58]

Well after attempting to mix 40:1....I cocked it up and got roughly a 30:1 ratio....bike won't run though because I can't get the carby to stop flooding the cylinder....checked the needle and seat and it won't stop the flow completely so I'll get a new one and see how I go from there....does anyone know the factory ratio or where I can retreive the info....
Thanks everyone....
Craig

[evo550]

I remember my '84 maico manual stating if using Maico something, something, something oil (can't recall what they called it) to mix at 100:1.............that's what it said! True!
I can hear the bullshit cough from here.

[NR555]

We've done a lot of work on oils, and it really varies from bike to bike.  We couldn't stop a CZ bore glazing up on synthetics.  I'd find that by the end of a raceday, I'd be noticeably down on power until we stripped it and honed the bore again.  It was literally a mirror finish glaze.  Motul, Rock Oil, Silkolene, Castrol R2; all the same result.  What's good for modern nicasil, ain't necessarily good for old bikes.

We switched to Castrol A747 and it has worked very well.  A lot of you guys would be familiar with this oil, although it's a little harder to find these days.  A747 is a castor/synthetic hybrid.  The fumes have quite obvious Castrol R qualities, and it works best at the richer end of the mixture range.  Castrol recommends where you would run R2 synthetic at 40:1, you'd run 747 at 25:1.

Graham Bell's thinking holds true, especially in two stroke racing like karting.  Air cooled sprint karts rev to silly numbers, and we always ran ours at 20:1 on Penrite mineral oil.

[mboddy]

Penrite Synthetic Fortified Mineral Oil is great stuff.
And Penrite is an Australian company.
I went through much trauma when they stopped selling TS40CC.
But I have now gone over to their Hi-Per Synthetic Fortified Mineral Oil.
Run at 24 to 1. Less oil is less power. 

[Rossvickicampbell]

Lozza - your comment regards "i haven't ever had a problem with......" interests me.  Most of us are just layman and hence so many questions being asked on this web site and great to see the feedback from so many (be that good or bad).  But tell me, I have been running Silkolene Comp Pro 2 SX for 3 years now at 40:1 in 4 different bikes and each time I have pulled a bike down everything looks good.  This is the only experience I have to go on and surely is better than saying it is 3/10ths of SFA!!  Surely if I said I had been running Bel Ray at 50:1 and seized a motor or two (which happened with the Yamaha boys when I was a lad) that while not qualitative or quantitative should also be taken into consideration.

I am interested in the more oil=more HP comments etc and when my bike arrived I was advised it was running at 50:1 but thought to be on the safe side to drop it down.

And again I am hearing comments of new 2 strokes being made to run at 100:1 to satisfy enviro concerns - surely these oils must be good for temp dispersion as well as the water cooling?

Anyway - same as usual - all good discussion

Rossco

[Lozza]

OK Rossco, first things first,NR555 try Agip Kart cheaper and easier to get hold(from Multispares) of than A747 and outperforms it in every way.Never tried the Penrite is that Castor or Castor/synthetic.Can I get a bottle from Super Shite Auto???

Rossco that phrase is very much subjective, if for instance an ex world champion/GP tuner said "I did such and such and never had a problem" it would carry more weight than some mug punter like myself saying the same thing.
Firstly it's realising just the scant amount of actualy oil needed to keep bearings spinning and not overheating, they ain't 4 bangers.What I would ask you is what would your engines look like if you had been running R30 at 20:1?Would the bike have increased performance?If you never try you will never know.What more oil does is provide a better conductor for heat to travel from the piston crown to the cylinder walls.With the added benefit of less friction hence less wear. It's that simple, and as Jennings and Bell proved with hard emperical data, that more oil made more power and the engine had less wear.
Again the lean oil ratios show just how little oil is actually needed, but a manufacturer getting Euro3 compliant and you having your engine wear less and make more HP are not the same thing.

[LWC82PE]

that Penrite TS40C 2 stroke oil was  V good stuff, i ran it in my TS 185 for years and i felt it was a real good oil. no Lozza its not shit from super cheap auto. it was a mineral oil, not castor. i know it was approved for ultra lights so thats why i knew it was good but then they changed the formula, name, packaging etc and now its says not for use in ultra lights and another person who works in the oil industry said that yes Penrite changed that oil and all the ultra light aircraft guys were spewing about that. ive got nothing bad to say about Peritre and its the main oil i use in all customers bikes except for Mobil in some newer bikes and Belray in 2 strokes now.

[marshallmech]

The company I work for is Penrites 2 oldest customer I have used penrite oils in my bikes since 1980 and have found it to be great. I will not use synthetic oil at all you mite as well use water. We have found in truck diffs and gearboxs that mineral oil is best Eg a truck with 650 thousand ks on  synthetic compared to an identical truck on same work loads etc the mineral oil box and diffs only need bearings the one with synthetic needs up to six gears replaced and usally a crown wheel and pinion in the diffs.