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Shee ain't running right


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are you using fresh fuel, same fuel octane, same pre-mix oil and pre-mix ratio?

Yes sir, he ran it with 93. I drained all the old gas that was out of it and put new gas in it..  The previous owner was running it 32:1 and the plugs looked pretty dark so I ran it 40:1 and the plugs are still looking the same. Im gunna have to wait and post pics of the plugs later tonight or in the morning. 

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Running your pre-mix 40:1 vs 32:1 is enough to require rejetting.

Now the pre-mix has more fuel ppm and less oil ppm.

The motor is now running richer even though your pre-mix is lean, fuel-oil ratio wise...

Can you help me understand a little better how that would require rejetting please. So does that mean that the more oil I put in the premix, the motor is going to run more lean? That sounds backwards to me, but I am limited in knowledge so thats why I posted here. 

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Can you help me understand a little better how that would require rejetting please. So does that mean that the more oil I put in the premix, the motor is going to run more lean? That sounds backwards to me, but I am limited in knowledge so thats why I posted here. 

 

OK, let me try to explain this.

 

5 gallons of fuel is 640 ounces.

 

32:1 pre-mix you need to add 20 ounces of oil to 5 gallons of fuel.  << 660 ounces of pre-mix.

In a specific volume of 32:1 pre-mix you will have less parts per million of gasoline and more parts per million of oil.

Now shoot 32:1 pre-mixed fuel thru your carb mixed with a fixed volume of air.

 

The 32:1 pre-mixed fuel has less actual combustible gasoline and is now mixing with a fixed volume of air flowing thru your carb into your motor.

The air/fuel mixture has less fuel for a fixed volume of air and is now actually leaner.

 

40:1 pre-mix you need to add 16 ounces of oil to 5 gallons of fuel.  << 656 ounces of pre-mix.

In a specific volume of 40:1 pre-mix you will have more parts per million of gasoline and less parts per million of oil.

Now shoot 40:1 pre-mixed fuel thru your carb mixed with a fixed volume of air.

 

The 40:1 pre-mixed fuel has more actual combustible gasoline and is now mixing with a fixed volume of air flowing thru your carb into your motor.

The air/fuel mixture has more fuel for a fixed volume of air and is now actually richer.

 

Your motor is jetted for 32:1 pre-mix.

Now you've now added more fuel to your pre-mix by pre-mixing 40:1.  << more ppm of fuel to oil ppm.

 

Your jets are too large and your motor is running rich and having a hard time getting on the pipe.

 

Try this, turn your airscrews out 1/2 a turn and raise the clip on your needle up 1 groove and report back.

By turning your airscrews out 1/2 a turn you've added more air to your idle circuit.

By raising the clip up 1 groove you've actually lowered the needle into the needle jet and leaned out the mid-range.

I bet it'll stay idling longer and it'll get on the pipe harder.

 

I hope that makes sense...

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OK, let me try to explain this.

 

5 gallons of fuel is 640 ounces.

 

32:1 pre-mix you need to add 20 ounces of oil to 5 gallons of fuel.  << 660 ounces of pre-mix.

In a specific volume of 32:1 pre-mix you will have less parts per million of gasoline and more parts per million of oil.

Now shoot 32:1 pre-mixed fuel thru your carb mixed with a fixed volume of air.

 

The 32:1 pre-mixed fuel has less actual combustible gasoline and is now mixing with a fixed volume of air flowing thru your carb into your motor.

The air/fuel mixture has less fuel for a fixed volume of air and is now actually leaner.

 

40:1 pre-mix you need to add 16 ounces of oil to 5 gallons of fuel.  << 656 ounces of pre-mix.

In a specific volume of 40:1 pre-mix you will have more parts per million of gasoline and less parts per million of oil.

Now shoot 40:1 pre-mixed fuel thru your carb mixed with a fixed volume of air.

 

The 40:1 pre-mixed fuel has more actual combustible gasoline and is now mixing with a fixed volume of air flowing thru your carb into your motor.

The air/fuel mixture has more fuel for a fixed volume of air and is now actually richer.

 

Your motor is jetted for 32:1 pre-mix.

Now you've now added more fuel to your pre-mix by pre-mixing 40:1.  << more ppm of fuel to oil ppm.

 

Your jets are too large and your motor is running rich and having a hard time getting on the pipe.

 

Try this, turn your airscrews out 1/2 a turn and raise the clip on your needle up 1 groove and report back.

By turning your airscrews out 1/2 a turn you've added more air to your idle circuit.

By raising the clip up 1 groove you've actually lowered the needle into the needle jet and leaned out the mid-range.

I bet it'll stay idling longer and it'll get on the pipe harder.

 

I hope that makes sense...

Okay that makes more sense.  Thank you for explaining.  So basically if this is actually what my problem is coming from, sounds to me like I just wasted 5 gallons of gas and should have just kept it at 32:1 like a good boy

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Or you can try what I suggested with your airscrews and needle clip position to see if my theory about you changing your pre-mix is valid.

That too, sorry didnt mean to leave that out, was not dismissing what you suggested, much appreciated. Ill be back with updates within the next day 

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Well, guess I'm wrong then.

There really just so close to each other that you don't need to rejet.

When I mix in my ratio rite I'm not always dead on the line. I'm over or under.

I've gone 40:1 on rides where I started to get low on oil.

 

Sent from my SAMSUNG-SM-G890A using Tapatalk

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There really just so close to each other that you don't need to rejet.

When I mix in my ratio rite I'm not always dead on the line. I'm over or under.

I've gone 40:1 on rides where I started to get low on oil.

Sent from my SAMSUNG-SM-G890A using Tapatalk

Maybe if he was jetted fat with his 32:1 and then switched to 40:1 that might be enough to need rejetting, but maybe not.

It would be interesting to see if a 1/2 turn out on the airscrews and lowering the needle cleared it up though.

 

I drop a pint of Yamalube 2R into my 5 gallon jug and that's that.

No ratio rite needed.

Been doing so for 20+yrs without a failure, knock wood...

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OP, read that article.

You said yourself that you changed your ratio from 32:1 to 40:1 because your plugs looked black and wet,

 

The oil in the pre-mix isn't what's making your plugs look that way, it's your jetting.

Your motor was jetted too rich with 32:1 to begin with and now you've added more fuel by going to 40:1.

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Chris, my bike is shooting oil out of the back like this article talked about.. Infact yesterday when i was letting it idle, it left a bird shot of oil on the ground and the back of my swing arm after revving it a few times.

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OP, read that article.

You said yourself that you changed your ratio from 32:1 to 40:1 because your plugs looked black and wet,

The oil in the pre-mix isn't what's making your plugs look that way, it's your jetting.

Your motor was jetted too rich with 32:1 to begin with and now you've added more fuel by going to 40:1.

e

 

I wanna make sure I rule out everything else though before I start changing things in the carbs like JD and the above article suggested.

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