Leaded fuel in 250f/450? (50/50 mix w/ pump)

avidchimp
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avidchimp 3/27/2025 10:32am
3/27/2025 10:32am

It takes me about 6-8 weeks to go through 5 gallons so I just spend the money on U4.4. Overkill I know, but damn does my bike run cleaner and smell better. Plus we only have super shit pump gas here in CA., so there is that factor.

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svincent08
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svincent08 3/27/2025 12:04pm
3/27/2025 12:04pm

Here is an article on Keefer's website.

https://www.keeferinctesting.com/2020-3-11-questions-about-av-gas-answered/

I don't think the vast majority of stock bike (or even minor modified bikes) would benefit from leaded fuel / higher octane rating. Leaded fuel does, however, cause deposits to build up. Particularly on the valves. I have disassembled several leaded fuel bikes and seen deposits on the valves preventing the valves from sealing well, causing pressure loss and power to go down.

Run pump or a legit higher energy density fuel (i.e. VP Pro 6) if you need relatively low cost power increase.

MXer391
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MXer391 3/27/2025 12:25pm
3/27/2025 12:25pm
MXer391 wrote:
I run 90 octane Non-ethanol fuel in all my four stroke MX bikes. Never had an issue. I don't see any reason to mix it with...

I run 90 octane Non-ethanol fuel in all my four stroke MX bikes. Never had an issue. I don't see any reason to mix it with 110 for a stock engine and stock ECU mapping. I put about 40 hours on my MC350F with just 90 Non-ethanol and that's what I've run in my '24 KX 450 so far. 

mx317 wrote:

My manual calls for 95 octane is why I mix mine with 110, but you do you.

My Kawasaki manual calls for 90 octane R/M2 minimum. Not sure why it would be a problem using a fuel that meets the recommended requirements and does not have ethanol to worry about but OK. 

mx317
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mx317 3/27/2025 12:29pm
3/27/2025 12:29pm
MXer391 wrote:
I run 90 octane Non-ethanol fuel in all my four stroke MX bikes. Never had an issue. I don't see any reason to mix it with...

I run 90 octane Non-ethanol fuel in all my four stroke MX bikes. Never had an issue. I don't see any reason to mix it with 110 for a stock engine and stock ECU mapping. I put about 40 hours on my MC350F with just 90 Non-ethanol and that's what I've run in my '24 KX 450 so far. 

mx317 wrote:

My manual calls for 95 octane is why I mix mine with 110, but you do you.

MXer391 wrote:
My Kawasaki manual calls for 90 octane R/M2 minimum. Not sure why it would be a problem using a fuel that meets the recommended requirements and...

My Kawasaki manual calls for 90 octane R/M2 minimum. Not sure why it would be a problem using a fuel that meets the recommended requirements and does not have ethanol to worry about but OK. 

You should be good then.

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RightHookNoCandy 3/27/2025 12:35pm
3/27/2025 12:35pm
avidchimp wrote:
It takes me about 6-8 weeks to go through 5 gallons so I just spend the money on U4.4. Overkill I know, but damn does my...

It takes me about 6-8 weeks to go through 5 gallons so I just spend the money on U4.4. Overkill I know, but damn does my bike run cleaner and smell better. Plus we only have super shit pump gas here in CA., so there is that factor.

Do you bring the pail with you to the track? or dump it in a gas can? 

Do most people just keep it straight in the pail and use it out of there at the track? 

avidchimp
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avidchimp 3/27/2025 1:06pm
3/27/2025 1:06pm
avidchimp wrote:
It takes me about 6-8 weeks to go through 5 gallons so I just spend the money on U4.4. Overkill I know, but damn does my...

It takes me about 6-8 weeks to go through 5 gallons so I just spend the money on U4.4. Overkill I know, but damn does my bike run cleaner and smell better. Plus we only have super shit pump gas here in CA., so there is that factor.

RightHookNoCandy wrote:
Do you bring the pail with you to the track? or dump it in a gas can? Do most people just keep it straight in the pail...

Do you bring the pail with you to the track? or dump it in a gas can? 

Do most people just keep it straight in the pail and use it out of there at the track? 

Honestly, I just top the tank off before I leave and take a small gas can with maybe a gallon in it and refill as needed. As it has no ethanol I don't mind it sitting in the tank during the week or two until the next trip. 

I see a decent number of people bring the actual fuel can, but I don't like exposing the whole can to warm track days and cool nights at home, that's where you get the possibility of moisture build-up.

kawasa84
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kawasa84 3/27/2025 1:23pm
3/27/2025 1:23pm
AMetts wrote:
I think anything but 93 pump for a stock engine modern 4 stroke is just wasting money but that's your prerogative.I usually choose 93 over 89...

I think anything but 93 pump for a stock engine modern 4 stroke is just wasting money but that's your prerogative.

I usually choose 93 over 89 non ethanol as that's usually what's in my area I also pump at least a half gallon into my truck before the can. If you are only getting a couple gallons of gas I like to make sure its mostly 93 not any 87 left in the hoses.  

Funny, I do this same thing

jameslowry
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jameslowry 3/27/2025 5:06pm
3/27/2025 5:06pm

all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever hurt anyone is a Bullit

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rogers
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rogers 3/27/2025 5:33pm
3/27/2025 5:33pm
jameslowry wrote:
all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever...

all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever hurt anyone is a Bullit

There is always someone on here that needs a brain transplant.

2
Last2Stroke 3/27/2025 6:05pm
3/27/2025 6:05pm
jameslowry wrote:
all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever...

all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever hurt anyone is a Bullit

rogers wrote:

There is always someone on here that needs a brain transplant.

There's a 50% chance his IQ has been lowered by lead...

https://www.verywellmind.com/lead-exposure-lowered-iq-score-of-half-of-americans-5222458

2
jameslowry
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jameslowry 3/28/2025 5:29am
3/28/2025 5:29am
jameslowry wrote:
all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever...

all you guys should check the compression ratio on your stock bike you really need to use leaded race fuel & the only lead that ever hurt anyone is a Bullit

rogers wrote:

There is always someone on here that needs a brain transplant.

get in line

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