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  #21  
Old 05-03-2016, 04:41 PM
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JFYI. Combustion engines were first designed to run on ethanol. Then the prohibition on alcohol came about. Hence how fossil fuels came about. That's worked out well. Not!

Our Aussie V8 Super Cars run on a 98% ethanol mix, made from sugar cane pulp. The only reason it's not 100% ethanol is so the pit crew don't drink it. Mind you. Not that Aussie's would ever do that.

Just sayin.

Last edited by 2 stroke bloke; 05-03-2016 at 04:51 PM.
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  #22  
Old 05-03-2016, 04:42 PM
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Remember that running too much octane will hurt performance due to the slower speed of the fuel burn. You want to only run what is required.

Paw Paw
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  #23  
Old 05-03-2016, 04:46 PM
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Our bikes were not intended to run on ethanol fuels. It causes major issues with breakdown of o-rings and gaskets in the fuel system and turns to varnish clogging pilot jets and other small orifices in short order.
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  #24  
Old 05-03-2016, 04:57 PM
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Our bikes were not intended to run on ethanol fuels. It causes major issues with breakdown of o-rings and gaskets in the fuel system and turns to varnish clogging pilot jets and other small orifices in short order.
Better tell my lawn mower and brush cutter that. It'll be complete BS, but, the oil company's will love you.

"There's a sucker born every minute".

Our pump gas would make yours look like liquid gold. AFAIK, we don't even have VP race fuel as an option. Our pump gas would cost around the same though.

Last edited by 2 stroke bloke; 05-03-2016 at 05:02 PM.
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  #25  
Old 05-03-2016, 04:58 PM
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Dragsters run on nitro methane. Maybe we should be running that in our bikes instead?
The addition of ethanol to our fuels here is a real problem making bikes run lean and of course the storage issues I already mentioned. The American motorcyclist association has been fighting legislation to allow more than 10% ethanol content in pump fuels because of that. I would attach some good reading on the subject, but we've been through that exercise once already haven't we???
"Can take a horse to water..."

Last edited by JMV; 05-03-2016 at 05:06 PM.
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  #26  
Old 05-03-2016, 05:05 PM
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Dragsters run on nitromethane. Maybe we should be running that in our bikes instead?
In that case, better go for .020.

Aviation fuel does the trick.
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  #27  
Old 05-03-2016, 05:12 PM
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You do realize that avgas is only 100 octane??? That's why it's called "100 low lead"
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  #28  
Old 05-03-2016, 05:25 PM
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You do realize that avgas is only 100 octane??? That's why it's called "100 low lead"
Sheldon Cooper would have gotten my attempted sarcasm. And, he has asperger's syndrome .

My original point was, that ethanol isn't the evil people seem to think it is. That'd be fossil fuels. That's all.

I raced Rotax 125 Karts for yrs (Aprilia 125 top end, right down to the air box). Won 2x Australasian championships. My engines were stock. For more compression I'd cut the washer off the Iridium spark plug. "K.I.S.S". It's all I had to do to be competitive against the "Blue Printed" engines. I worked at the Kart shop, I had the option to do a lot more.
In Karts, people will pay thousands for a 10th of a second gain. Again, "There's a sucker born every minute". They kept us in business.
'
Again, just sayin.

Last edited by 2 stroke bloke; 05-03-2016 at 05:46 PM.
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  #29  
Old 05-03-2016, 06:06 PM
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The us blends of "E" fuels do in fact hurt the rubber parts of the fuel system and do allow for a clear coating to develop on the carb jets. It has been a big issue from the start and has cost us and small engine customers many dollars as a result. This is not a fantasy in our country.

Paw Paw
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  #30  
Old 05-03-2016, 06:24 PM
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Thank you. Bloke, if you knew a quarter of what you thought you knew, you'd be a very valuable resource here on the site.
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  #31  
Old 05-03-2016, 06:38 PM
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Originally Posted by PawPaw View Post
The us blends of "E" fuels do in fact hurt the rubber parts of the fuel system and do allow for a clear coating to develop on the carb jets. It has been a big issue from the start and has cost us and small engine customers many dollars as a result. This is not a fantasy in our country.

Paw Paw
That must be a result of the Indian owned gas station syndicates diluting their fuel again.
We get that to .

Funny cause it's true .
We tested the Indian (Independant) 100% octane fuel at the Kart shop and the bike shop.
I only use BP Ultimate 98%. Always from a newer servo.


Just out of curiousity. How much is the VP race fuel?

As for the Squish settings. My advice to the OP is to send it to someone like Eric Gore etc. You'll get the best job from the person who's best suited to do the job.
You'll be supporting the Industry you enjoy participating in as a result.
I don't do the job if I believe someone else can do it better. IMO. Learing properly, requires a passionate and keen Interest in the given subject. I.e, If my 2T engine builder wasn't getting paid, he'd still be building 2T engines. Hence why I get him to do the jobs that I'm just not that interested in. He has the tools, the knowlege, and the passion to do the job better than I ever could.
I just have the common sense to take advantage of that.

Eric Gore, and people like him, IMO, are a resource worth investing in. They are the knowlege base.

Last edited by 2 stroke bloke; 05-03-2016 at 07:13 PM.
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  #32  
Old 05-04-2016, 08:49 AM
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Originally Posted by PawPaw View Post
Remember that running too much octane will hurt performance due to the slower speed of the fuel burn. You want to only run what is required.

Paw Paw
Which is why you should set up the engine for peak performance with better fuel in mind... more compression, better porting thus more dynamic compression, adjust the spark curve to optimize performance, ect. If the owner was happy with the stock performance this conversation wouldn't be taking place. This guy has won several series championships in the pro class on 4-wheelers and has recently switched to motorcycles... More power is the goal, especially mid-range and snap off the bottom.

I've ridden his bike and it's pretty mild for a cr250
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  #33  
Old 05-25-2016, 11:01 AM
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Ok for a quick follow up. I got the squish redone for race fuel AV100LL better. The cranking compression is now 225 psi. The bike starts one kick even in gear with the clutch halfway pulled, it runs better everywhere and responds to jetting changes much better. It pulls off the bottom like a tractor and rips on the pipe like a MX bike should. I have no idea why anyone would want to make a race bike engine into a low compression pump gas burner.
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  #34  
Old 05-25-2016, 11:18 AM
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So what did the squish turn out to be?

Paw Paw
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  #35  
Old 05-25-2016, 02:27 PM
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Originally Posted by lankydoug View Post
Ok for a quick follow up. I got the squish redone for race fuel AV100LL better. The cranking compression is now 225 psi. The bike starts one kick even in gear with the clutch halfway pulled, it runs better everywhere and responds to jetting changes much better. It pulls off the bottom like a tractor and rips on the pipe like a MX bike should. I have no idea why anyone would want to make a race bike engine into a low compression pump gas burner.
They don't get made into... they come that way from the manufacturers. Some people can afford to make all out race bikes. I bet they're fun. Some of us ride for fun and would rather have a day at the track be $10 in gas and $20 in practice fees and keep the cost to build, maintain, and run our bikes as low as possible.
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  #36  
Old 06-11-2016, 12:53 PM
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Originally Posted by gusco View Post
They don't get made into... they come that way from the manufacturers. Some people can afford to make all out race bikes. I bet they're fun. Some of us ride for fun and would rather have a day at the track be $10 in gas and $20 in practice fees and keep the cost to build, maintain, and run our bikes as low as possible.
Actually they do get made that way. Production specs are not precise and they error on the safe side so if your cylinder was made with .020" extra clearance and your head was out of tolerance by the same you could have double the desired squish. The next guy might get lucky and get a near perfect engine. The same holds true for automobile engines which is why blueprinting an engine done.

I read this entire link http://iheartstella.com/resources/ma...nce-Tuning.pdf and the author claims that too much squish clearance can cause the edge of the piston to get hot and lead to pre ignition and detonation so not only do you lose performance but you are risking engine failure.

Where I live AV100 is $3.98 per gallon and pump 93 no ethanol is $2.60 so the difference of $1.38 per gallon would likely cost you about $5 extra per day.

What gets me is that a lot of guys will shell out $200 or more for an exhaust silencer and most show no gain in horsepower or torque yet (if your squish clearance is out of spec) for much less you can guarantee and substantial gain.
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  #37  
Old 06-11-2016, 05:51 PM
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So what did the squish turn out to be?

Paw Paw
X2

...is the answer to this question being avoided..?
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