OZ ATV :: The Australian ATV Forum

[gammie61]

I know I have seen this subject on here before but I can't find it.
What oil ratio should we use to run in our banshee?
It's got 1 mil oversize procross pistons.
How long is the run in time & what is the procedure?
Thanks
Peter.
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06 LTZ400
2000 BANSHEE
Lousy rider.
Eats lots mud now it's wet.

[Overlord]

Hey Gammie61, have a look at the Tec links above your post. Its in there.


Regards Bad Banshee

[TUFF AS]

i run 1/25 oil ratio to be on the safe side
when you a running it in just take it easy just give it a quick squirt on the trottle than stop switch the bike and pull one of the plugs out just to check the tuning is alright the plug should be a tan brown colour little bit black wont hurt it. than just take it easy for a coulpe of hours than slowly build your speed up after that.

cheers brad,
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07 BANSHEE 91hp atw at the moment
04 WR450F still yet to know hp

[doorslammer]

dont use fully synthetic oil

[4stroker]

warm it up and ride it!
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2002 SE Banshee

[gammie61]

Fantastic fellas, thanks
That tek link was hopeful. I think it will suit the youngfellas style of riding. I wasn't too hopeful of him just putting around.
We'll run 25:1 nonsynthetic oil fuel mix.
_________________
06 LTZ400
2000 BANSHEE
Lousy rider.
Eats lots mud now it's wet.

[Banshee250R]

25:1??

i run mine 40:1 straight from the dealership
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Doin skids for the kids and doughnuts for the grown-ups
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[4stroker]

yeah i run 25:1

6 years old still on original pistons!
_________________
2002 SE Banshee

[TUFF AS]

Banshee250R wrote:

25:1?? i run mine 40:1 straight from the dealership

yea that will be the good old yamaha facts!
_________________
07 BANSHEE 91hp atw at the moment
04 WR450F still yet to know hp

[SIKMIC]

We normally run 40:1. Start it up and let it warm up then turn it off and let it cool down to stone cold. After you have done this once or twice take it for an easy ride, don't labor the engine but dont rev it up to much, for around 15 minutes, let it cold back down to stone cold. Then it should be ready to race.
_________________
Mic

YFZ450
Thanks to ATV's Unlimited &
Luke Beechey Motorsports
mic902@hotmail.com

[4stroker]

in the banshee owners manual doesnt it say to run it 20:1? or theres a sticker somehwere on the bike like that
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2002 SE Banshee

[TUFF AS]

4stroker wrote:

in the banshee owners manual doesnt it say to run it 20:1? or theres a sticker somehwere on the bike like that

it sure does mark! it says it in the manual!
_________________
07 BANSHEE 91hp atw at the moment
04 WR450F still yet to know hp

[4stroker]

check out these extracts from Graham Bells 2 stroke performance tuning book:



By fourstroker at 2008-03-11


By fourstroker at 2008-03-11


By fourstroker at 2008-03-11
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2002 SE Banshee

[OZ_450]

yeah true i run 25:1 also

but i also didnt run a tank thru it or my 450's like the shop and book says think i spent hmm 1.2 hrs then was up it on banshee and ltr
_________________
black covered in 5.7 powered oversize quad
model vx ss 350 hahaha
enough bass to compensate for lack of skills
Empty Wallet Racing proudly on track for GM Motorsport

[gammie61]

I bought a small Yamaha outboard once & its recomended mixture ratio was 100:1. The dealer (from Tully) said don't go under 50:1 up here because the moisture in the air will rust the bore.
We were running 33:1 in our Banshee & it seized after sitting for a few months.
I know a lack of maintainance is the main cause here & that it should have been turned over on a regular basis, but I did consider the possibility of their not being enough oil in the engine to start with.
I will not complain if I have to cop a bit more smoke the next time one of my boys rips past me.
This quad only cost us $3,800 a few years ago. This engine rebuild is over $2,000 worth.
_________________
06 LTZ400
2000 BANSHEE
Lousy rider.
Eats lots mud now it's wet.

[gammie61]

I have got another little personal insult to add here.
We were cleaning out the shed last week & we debated throwing out an old chain off the 450. It seemed to be in pretty good nick. My argument was that if James took it off & put a new one on it was because he didn't think it was any good.
So we dumped it.
So today we went out & bought a new chain & sprockets for the Banshee.
The one we threw out was off the Banshee & the reason it appeared so good was that it had only done a few rides.
Sometimes I wish I had just a little bit of intelligence.
_________________
06 LTZ400
2000 BANSHEE
Lousy rider.
Eats lots mud now it's wet.

[4stroker]

$2000 for a rebuild? did you pay someone to do it or do it yourself?
_________________
2002 SE Banshee

[bullet]

I'd say half of Graham Bells 2 stroke tuning article is just plain wrong.
Mixed up with a lot of facts, it probably doesn't read half bad.
Be very carefull what you read.
Anyone could find twice as many articles that recommend the opposite and show a table of results to support it.

Most two stroke oils lower any fuels combustability and octane rating.
Common sense then says the more you put in the worse it will go...
but you do have to lubricate and protect your engine.

He lables synthetics as having half the lubricity of "some" castor and mineral oils.
I'd say that's crap, and he has bunched castor and mineral together to make the claim.
Castor oil has the highest lubricity, then synthetic, then mineral.

Manufacturers don't recommend ratios that wont get you through their warranty period.
If anything they'd be idiots to not be a bit conservative and not recommend a richer oil mix just incase their product is used in an unforseen extreme situation.

If you use a recommended oil at the recommended mix you 'should' be fine.
If you are running a higher specification oil (most synthetics), then of course you would need less of it to get the job done safely.
But that guess is up to you.
If it said 25:1 with a top name oile I'd happily go 32:1
If it said 40:1, I'd happily go 50:1

If more oil makes more power.... "16:1" crap.
Why wouldn't we start running a bit of oil in 4 strokes just for the power advantage.

I think Graham Bell must be Saddam Huseins half brother or something.
Who's paying him.
_________________
Can-Am X Team
Bullet #Y12. MrsB #Y18.

[4stroker]

no worries mate you are entitled to your opinion but i think ill stick with ol graham bell lol

have you read his books?
_________________
2002 SE Banshee

[bullet]

No I haven't (your point appreciated).
I have read and seen a lot of contradictory articles though.
Even the old May and Crouse trade school books have a different view.
Ian Williams tuning has some good stuff too (well, other views).
But who knows.
I learnt a lot of a bloke who ran high performance boat motors in the Avon Decent in WA. Those guys use heaps of different fuel concoctions, blends of oils, plus alcohol and metho as anti water glomeration insurance.

I reckon go-cart guys would have to be the best to talk to.
I have heard a lot of them say the leaner the better. One national champ over here said "on a big day, we'll run as lean as we have to to win and just hope it doesn't go bang". Those guys blow them up all the time trying.

I did like Graham's exhaust 'wet or dry' point though.
Sort of if it's wet - go leaner on the oil. If it's really dry go richer.
I think that would offer a good reflection of how you ride v's temperatures and fuel-oil ratios.
Eg. a really hot day in the sand dunes might be 32:1 and a winter MX meet might be 40:1

If most average riders tried running 16:1 thinking they'll make more power because they 'saw it written somewhere'... I reckon they'd clag up plugs in no time.

It all makes for a bloody interesting topic though.

What have people gone down to in Banshees and either got away with or discovered that too lean was the reason for failure? 60:1 maybe?

Who is the oiliest rider out there? Any 16:1's?
_________________
Can-Am X Team
Bullet #Y12. MrsB #Y18.

[azza450]

This is starting to make for some interesting reading guys, all without anyone getting their knickers in a twist.

When I used to race MX on my banshee I've been out to 50:1 with motul 800 and 98 octane fuel on a cooler day without any problems.

The motor was fresh and still pretty stock apart from a bit more compression, reeds, spacers, 4 degree timing advance and a few other tricks.

It was however jetted pretty heavy, 270 mains with stock pipes but never fouled a plug unless someone else was riding it.

Would hang with a worked 450 no problem.

[4stroker]

dont forget that the richer your fuel:oil mix is, the richer your jetting has to be. this is because more oil in the fuel means less fuel in the fuel:air mix, resulting in lean combustion process.

consider this scenario happening inside your 2 stroke engine:

1. the piston goes up, uncovering the inlet ports at TDC and letting in a fresh charge of fuel,oil and air (at the same time as completing a combustion process while the pistons up there, aint 2 strokes marvellous!)

2. the piston goes down, pushing the mix down into the crank case and up the transfers.

3.some of the oil lubes the little end and under the piston, some of the oil lubes the big end and main bearings, and some of it lubes the bore as the piston goes back up compressing the mix.

4. by the time the piston is back up at TDC and the combustion happens, there should be little to no oil left, leaving only fuel and air. of course there is always some, resulting in the beautiful blue smoke out the tail pipe. if there is too much oil, your plug will foul and oil drip out the exhaust.

so if a bike runs good on 25:1, and doesnt foul plugs and drip oil, why on earth would you try 50:1?? that is half the oil to lube all those parts! surely all those bearings will spin better with more oil, and the bore will be more slippery, resulting in more power?

also keep in mind even graham bell said that going to 16:1 resulted in a power increase that probably isnt even measurable (2%) so you wouldnt be trying it for a power increase, youd try it for the increase in reliabilty/engine longetivity!

im pretty sure the 100cc karts run rich fuel oil ratios, like 20:1 or 25:1, but they are a bit of a different kettle of fish, fixed gearing and their weird carbys arent really comparable to bikes/quads.

also i have read somewhere that KTM reccomend like 60:1 for one/some of their bikes!? anyone know if thats true? crazy if it is!

just for the record i run silkolene comp 2 (semi synthetic) oil in my bansh @ 25:1, jetted fairly rich (310 mains with pipes filter and no air box lid)

it is a 2002 model and i only just re-ringed it 2 or 3 months ago! doesnt foul plugs or drip oil either...
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2002 SE Banshee

[bullet]

Yeah 2 strokes are amazing how they fit everything into two strokes at 11,000rpm. That's 183 times a second that the whole process happens.
Absolutely regardless of the engine, if you are using petrol the air fuel ratio needs must be between 10:1 and 16:1 by 'weight'.
The stoiciometric spot on ratio for most complete combustion is 14.7:1.
1 litre of petrol = about 10,000 litres of air.
Think about how many litres of air have gone through your engine if you filled the tank a few times in a weekend.
I'm pretty sure those facts are good... So...

If a 350cc Banshee pulls in say 300ml of air per revolution it should pull in about 0.03ml of fuel and oil mix through the carby (sounds small but that's a third of a litre per minute of fuel at 10,000rpm. which would have to be close to what a banshee chews up to do a 65 second speedway race).
Of the 0.03ml of fuel mix, at 50:1... 0.0006ml of that mass is your lovely oil.
In the 350cc cylinders way less than 10% of that would come into contact with an internal engine surface and have a chance to stick for lubrication.

Now were down to six one hudred thousandths of a cc or ml that protects your engine when the spark plug throws maybe a 1 tonne impact at the top of your piston 183 times a second.

I'm sure if they thought about that stuff before they designed the first engine, they would have thought 'bugger it' it's never going to work, and even if it did it couldn't last more than 5 minutes

It really is a bees dik of oil, so maybe who cares if it's twice or half a bees dik.
By that thought if 32:1 was standard, you might get away with either 16:1 or 64:1.
(I'd stay around the 40 and under the 50 though).
_________________
Can-Am X Team
Bullet #Y12. MrsB #Y18.

[Quad]

look its a lot of words to read over and over, if your a weekend rider and you wont it to last use the 25:1 ratio. you my have to change the plug now and then. use std plug ,not the fancy ones .

Then when you get a little more keen try the different ratios your 32 ,40 , etc just stick with the same oil .

the best ratio is just before the motor locks up with correct jets then come back one step. works for me .

I ride full pin banshee on tar mine runs sweet. by now.
go the out board oil its cheap annnd it works. it mixes 100% stir not shaken.

[4stroker]

haha darren you dont have to read it if you dont wanna!

ive read about using the outbaord oil b4, but it doesnt make much sense to me, dont most 2 stroke outboards only rev to like 6000rpm?

your average banshee will rev to 10000!

Quote:

the best ratio is just before the motor locks up with correct jets then come back one step. works for me .

that might be the case for your air:fuel ratio (bullet mentioned it b4, stoichiometric ratio) but i dont think its good advice for fuel:oil ratio...

Quote:

if your a weekend rider and you wont it to last use the 25:1 ratio. you my have to change the plug now and then. use std plug ,not the fancy ones . Then when you get a little more keen try the different ratios your 32 ,40 , etc just stick with the same oil .

graham bell has proven with dyno results that leaning out the fuel:oil ratio doesnt help horsepower, in fact it kills horsepower?
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2002 SE Banshee