Race fuel seized up my bike???

moto116
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7/11/2010 8:01am Edited Date/Time 1/26/2012 4:13am
I went to start up my bike after 4 weeks of not riding (bike ran great when i shut bike off). The kickstarter wouldn't budge. Took off the head and cylinder and found deposits from the fuel at the top of the piston. There were large chunks of deposits and looked like it basically corroded the top of the piston. I believe the race fuel i use is true blue 110 octane.

Is this leaded fuel, is that why it did that to my piston? I store my bike in a really damp barn at my parents house because that is my only option, did the moisture and dampness cause this?

Please help with this problem. Has anyone ever heard of such a thing?
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moto116
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7/11/2010 8:08am
I have a crf250r
newmann
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7/11/2010 8:17am
Absolutely! I'm no fuel expert, but race fuel appears to absorb(?) moisture from the air. Drain the tank into a glass jar and I'll bet you the fuel is milky looking. I have a high compression 74 CR250 vintage racer which runs on 116 octane race fuel. It has suffered the same fate, only way worse than you describe. Being it has a cast iron cylinder bore it has rusted up solid before. Cylinder wall, wrist pin and rings all developed enough rust to lock it up solid in a few weeks time.

Only way to prevent it is to run some pump fuel through before putting it away or shoot a little WD40 in to displace the moisture.
newmann
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7/11/2010 8:19am
Unless you are running a high comp piston,you should not need the race fuel anyway. 110 octane in a stock engine could actually hamper performance.
moto116
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7/11/2010 8:38am
thank you for your reply, i had no idea that race fuel would do that to my piston. I have a 13:5 compression (i think that's what it is, i know it's the next higher than stock, it may be 13:1 compression). What fuel do you suggest i run? Also, will ethenol hurt these high performance engines?

thanks again for you help

The Shop

sxf138
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7/11/2010 11:20am
ANytime i plan on letting the bike sit for more than a few days, i drain race fuel. It will gum up in your motor. And like newmann said unless you have a high compresison piston, your throwing your money away.
moto314
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7/11/2010 11:57am
13.5:1 Compression is a bit risky on pump fuel, but 110 octane is over kill. I run 95 octane with 13.5:1. Also store your gas in a metal container and not on cold cement ground, this will help keep moisture out. Plastic jugs are ok for a few weeks, but 4 weeks I would drain the gas and put it in the metal container.
CamP
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7/11/2010 2:44pm
100LL Avgas is a good choice if your are running a high compression piston.

Here's an avgas price finder.

100LL

Hank_Thrill
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7/13/2010 4:56pm
Does this hi-compression piston and 110 octane stuff apply to two-strokes as well?
moto314
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7/13/2010 7:49pm
Does this hi-compression piston and 110 octane stuff apply to two-strokes as well?
yes
prillernut
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7/14/2010 9:18am
CamP wrote:
100LL Avgas is a good choice if your are running a high compression piston.

Here's an avgas price finder.

100LL

somewhat OT - when I got back into riding a couple of months back, I considered running avgas til I heard they're not supposed to sell except for aircraft use only - the way it sounds, an FBO can be fined for filling a 5-gallon can for you?
CamP
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7/14/2010 1:14pm Edited Date/Time 7/14/2010 1:20pm
CamP wrote:
100LL Avgas is a good choice if your are running a high compression piston.

Here's an avgas price finder.

100LL

prillernut wrote:
somewhat OT - when I got back into riding a couple of months back, I considered running avgas til I heard they're not supposed to sell...
somewhat OT - when I got back into riding a couple of months back, I considered running avgas til I heard they're not supposed to sell except for aircraft use only - the way it sounds, an FBO can be fined for filling a 5-gallon can for you?
I've been buying it for 30 years and I've never been told I can't fill up my fuel jug. The only restriction I know of is you can't use it on the street. Most muni airports have self serve pumps with no attendants.
typhoon67
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7/18/2010 9:26am
avgas is designed for FIXED THROTTLE/HIGH ALTITUDE use, the blend they use is not good for varied throttle use.
Most race fuel is not corrosive, the environment you are storing the machne is likely more to blame.
Always drain fuel from carb/tank after each use, especially if pump gas, the ethanol will gel in a couple weeks.....and ethanol does retain moisture that leads to corrosion
I have used C12 for 20 years and never had any trouble with corrosion......2 strokes that are using a castor premix oil (Maxima 927, Castrol "R", blendzall etc) will suffer from the oil's properties, the oil will cause corrossion during storage, but not the gas.
Compression ratio and timing control will determine which fuel you need, 13.5 will be best with 105 octane up to 117.....anything higher is not helping.
Mixing pump and race fuel does increase the octane but it will not be stable nor consistent, and you will never know what octane is actually attained, it is a bad practice to mix these as throttle response will vary.
1
CamP
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7/18/2010 9:36am Edited Date/Time 7/18/2010 9:43am
typhoon67 wrote:
avgas is designed for FIXED THROTTLE/HIGH ALTITUDE use, the blend they use is not good for varied throttle use. Most race fuel is not corrosive, the...
avgas is designed for FIXED THROTTLE/HIGH ALTITUDE use, the blend they use is not good for varied throttle use.
Most race fuel is not corrosive, the environment you are storing the machne is likely more to blame.
Always drain fuel from carb/tank after each use, especially if pump gas, the ethanol will gel in a couple weeks.....and ethanol does retain moisture that leads to corrosion
I have used C12 for 20 years and never had any trouble with corrosion......2 strokes that are using a castor premix oil (Maxima 927, Castrol "R", blendzall etc) will suffer from the oil's properties, the oil will cause corrossion during storage, but not the gas.
Compression ratio and timing control will determine which fuel you need, 13.5 will be best with 105 octane up to 117.....anything higher is not helping.
Mixing pump and race fuel does increase the octane but it will not be stable nor consistent, and you will never know what octane is actually attained, it is a bad practice to mix these as throttle response will vary.
typhoon67 wrote: "avgas is designed for FIXED THROTTLE/HIGH ALTITUDE use, the blend they use is not good for varied throttle use."



This is not correct. Avgas is designed to prevent detonation during wide open throttle, sea level take offs. It is not designed for fixed throttle at high altitudes. All piston aircraft have controls to lean out the air/fuel mixture to compensate for high altitudes at a fixed throttle position.

BTW, for many of their early years, VP used 100LL as the base fuel for C12 and their other race fuels.
typhoon67
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7/18/2010 9:42am
Yes the aircraft do have mixture controls, but the fuel is specially formulated for this environment........
CamP
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7/18/2010 11:41am Edited Date/Time 7/18/2010 1:01pm
typhoon67 wrote:
Yes the aircraft do have mixture controls, but the fuel is specially formulated for this environment........
It's designed to resist detonation during full power acceleration at sea level.
pelley3
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3/28/2011 8:58pm
He is right, I'm a pilot and the mixture control compensates for the altitude not the fuel. It IS designed to prevent detonation. farther more it is made to a much higher standard than pump fuel and I believe is a GREAT fuel to run in a RACE bike! Its is WAY cheaper than vp with competitive resultsI usually mix 100LL 1:1 with 94 pump gas then add Lucas octane booster. I feel the high test pump fuel dilutes the lead a bit and provides a better more complete combustion with my timing (using hot cams). You may need to re jet for those of us still using carbs :p. Anyone know how altering the fuel works in a EFI bike?

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