So I got my Zilla running again today. 87 octane, 40:1. It ran away on me so I killed it.
I pulled the plug and was kicking it over and I felt air the left side engine cover.
How bad is this?
Terrible!!!! You're running 87 octane pump gas at 40:1!!! Just awful!!
Oh wow, shes running super lean with that air leak. Even without the air leak. The mixture is to lean. My weed whacker runs 40:1..
Terrible!!!! You're running 87 octane pump gas at 40:1!!! Just awful!!
I had 93 at a 32:1 and it just kept fouling the plug. Some googling around recommended trying 40:1
LOL
Oil ratio and jetting aren't interchangeable.
Oil ratio is also not responsible for fouled plugs, that falls on improper jetting.
If you're getting a leak in the case it's either from bad crank seals or a
**** case.
If you can actually FEEL the air leak, you've got a serious problem (unless you're feeling air being moved by the flywheel).
Time for a leak down test and visual inspection...
West Texas, good job taking care of the newbies, good thing ur here
seal can be changed with out tearing motor apart.
I think what I'll do is throw this in my local scrap pile. It can be melted down to a fine new Kia
Terrible!!!! You're running 87 octane pump gas at 40:1!!! Just awful!!
I had 93 at a 32:1 and it just kept fouling the plug. Some googling around recommended trying 40:1
Fouling plugs is a jetting issue. Don't try to compensate by changing your fuel mixture.
Edit** Oops, i see Tex already said this.
So you could run 20:1 fuel mixture, but the plug wouldn't foul? Oil does not burn as gasoline does, and if there is too much oil in a fuel mixture, the plug WILL foul.
Carb jetting can also be a contributing factor but only if the proper fuel mixture is used (which seems to be presented with conflicting evidence on every forum.)
Blanket statements are seldom correct, and I prefer to address each issue with an accurate diagnosis.
Many of us are running between 20:1-32:1. Don't hear of any one fouling plugs when their jetting is right. I'm running 32:1 and haven't fouled a plug in 20 hours of run time.
I concure. I have run 32:1 general riding and 24:1 hard duning for 30 years and plug fouling never a problem. I have fouled many plugs at high altitude bu being jetted too rich for the altitude. Lean out the jetting and keep fuel oil mixture the same and no fouled plug.
Oil isn't what fouls the plug up, it's the carbon residue from improper fuel combustion.
Remember that carbon is a type of conductor (they use it for brushes on electric motors), and you're essentially coating the porcelain insulator with it.
Build up that carbon residue enough and the spark will short out at the base of the insulator instead of jumping the gap...hence a fouled plug.
Burning oil doesn't create any more carbon residue than fuel does, unless there's no more oxygen to burn (fuel mixture too rich).
If jetted correctly and running, the spark plug will be hot enough to burn any oil trying to short the plug out regardless of oil ratio.
The practical limit to oil mix ratio is probably like 5:1 to 10:1, I dunno, it all depends on how long you run it at full throttle.
That kind of oil ratio isn't good for cruising around with your grandmother.
there is a point where too much oil is bad.
Gas cools the motor, not oil. It just lubes it. So, if you running too much oil you can burn up the motor. Just like running straight gas will lock up a motor.
Confused yet?
I change out my plug at the beginning of every season.... just because. I haven't fouled a plug since i first completely redid my bike. Over 10 years.
Q2W...you're almost right.
Gas does cool the engine, not oil....no question there.
But, if you're using enough gas for proper jetting (ie rich of stoich, 11:1 or whatever), there will be enough fuel to cool it.
You'll need some huge jets if you're running something stupid heavy like a 10:1 ratio, but as long as the AIR:FUEL ratio stays the same, the fuel:oil ratio won't matter.
If you were to up the oil ratio to 10:1 after jetting your bike to 32:1, then yeah, there won't be enough fuel, it'll run lean, and you'll destroy the piston, because that extra oil changed the air:fuel ratio.
Only so much liquid will pass through a jet, so if you're jetted for pure fuel (for simplicity's sake) and then go with a 1:1 fuel:oil ratio, it will be the same effect as giving the engine half as much fuel.
Change the jet out for something that flows twice as much and you'll be back to the same air:fuel ratio, but with all of that oil mixed in with it.
Something else to consider...when a bike is run on methanol, the air:fuel ratio changes and you're putting in something like 15-20% more fuel to maintain rich of stoich.
That means the engine is seeing 15-20% more oil too, if you kept the same ratio that you used with race gas.
Most of the time though, the oil ratio used by alky 2-strokes is heavy, like a 20:1 ratio.
On top of the heavier ratio, there's also more oil going into the engine because the jets are bigger too.
Those engines are probably seeing the equivalent of a race fuel engine mixed at 15:1, but I'm too lazy to do the exact math on that.
So you could run 20:1 fuel mixture, but the plug wouldn't foul? Oil does not burn as gasoline does, and if there is too much oil in a fuel mixture, the plug WILL foul.
Carb jetting can also be a contributing factor but only if the proper fuel mixture is used (which seems to be presented with conflicting evidence on every forum.)
Blanket statements are seldom correct, and I prefer to address each issue with an accurate diagnosis.
Plug fouling can also be a riding issue.
High performance two strokes need to be ridden hard enough to keep the plug clean. A ride with the wife and kids on their bikes will usually result in a fouled plug regardless of the jetting or oil ratio on the LT 500.
stoich for methanol is 5:1. i run 24:1 with VP M1 mixed with klotz benol. I purge out the methanol with pump gas mixed with 2 stroke marine oil at 24:1. tha. spray fogging oil in.
