unleaded or leaded race gas


10 replies to this topic
  • dirtguy

Posted February 03, 2005 - 12:57 PM

#1

i did not see any threads with info on what type of fuel is best for the 2005 WR450. the Yamaha manual says unleaded 95 or higher only. i put leaded 110 in on the last ride (before i got the manual) and the bike ran fine. in Calif you can only get 91 at the pump.

  • un450azul

Posted February 03, 2005 - 01:00 PM

#2

There are select Unocal stations that sell 100 octane at the pump. One is Gilbert/Commonwealth in Fullerton.

  • Gadsen

Posted February 03, 2005 - 06:03 PM

#3

i did not see any threads with info on what type of fuel is best for the 2005 WR450. the Yamaha manual says unleaded 95 or higher only. i put leaded 110 in on the last ride (before i got the manual) and the bike ran fine. in Calif you can only get 91 at the pump.


Well, lead is good techncially, but bad for a cat converter. I'm suprised you even found leaded fuel. Advantages to lead is a great lubrication and it boost octane. There is nothing on your bike that would be hurt with leaded fuel. Just dont dump the extra in your late model car or you'll be getting a catalyst effeicency code P0420 when the lead deactivates it! :cry:

  • timcook

Posted February 03, 2005 - 07:17 PM

#4

This topic comes up way too often. If you plan on using a leaded fuel you'll only find AV gas designed only for aircraft that contains tetra ethyl lead such as 100LL (low lead) at an airport. Lead has been phased out of automotive gasoline for nearly 10 years in the US. The octane rating specified by Yamaha is critical to adhere to regardless if the bike runs fine with a lower grade. You can get creative by mixing 91 from the pump and "race" gas or an additive. Virtually all octane "boosters" contain the same ingredients. They vary on price and concentration levels of MTBE.

  • mtrablue

Posted February 03, 2005 - 08:55 PM

#5

do a search on fuel topics. premium unleaded is fine. why would you waste your time putting leaded gas in an '05 bike made for unleaded? the 95 octane rating in your manual translates to about 91 or 92 by the way our fuel is rated.

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  • BIGMatt

Posted February 03, 2005 - 09:17 PM

#6

This topic comes up way too often. If you plan on using a leaded fuel you'll only find AV gas designed only for aircraft that contains tetra ethyl lead such as 100LL (low lead) at an airport. Lead has been phased out of automotive gasoline for nearly 10 years in the US. The octane rating specified by Yamaha is critical to adhere to regardless if the bike runs fine with a lower grade. You can get creative by mixing 91 from the pump and "race" gas or an additive. Virtually all octane "boosters" contain the same ingredients. They vary on price and concentration levels of MTBE.


Whatever you do, DO NOT USE airplane AV-Gas 100LL. Avaition fuel is formulated to burn MUCH HOTTER in low compression aircraft engines that run at high altitude where the outside temperature is below freezing. You best bet it to buy real 'race fuel', leaded or unleaded, from a gas station or local shop. There would be no harm in running leaded fuel in a WR engine, it may run better because of added lubricity. Not to be a tree hugger-enviro freak-save the gay whales guy, but leaded fuels are bad for the atmosphere that you and I breathe.

  • Kirk_Ingram

Posted February 03, 2005 - 09:48 PM

#7

Since I found TT, I've been a little curious what everyone else ran for fuel. I just haven't made a post about it yet. Manual say's to run 95, and I run a 50/50 mix of pump 91 and 100 unleaded race gas. I've also been in several situations where I had to run 91 pump gas only (street legal can do that to you). Always ran the same either way.

What fuel/mix do most of you run??

BTW, I run 110 leaded in my old two stoke (mix with 91 pump) and I like to add a little leaded gas to my old Plymouth to help out the exhaust valve seats. So that's means two kinds of race fuel stored in the garage. If I can ditch the 100 unleaded I use for the wr and keep the leaded only on-hand, that would be very nice! I've always read that leaded gas will work in most any 4-stroke type engine, but is very hard on cat. convertors.

So running a mix of leaded fuel in our 4-strokes is okay? K

  • BubZ

Posted February 04, 2005 - 04:35 AM

#8

I'm glad to see mtrablue's response. I know just enough about fuel to be very dangerous...but I knew the formula in the manual wasn't the same as used in the states to calculate octane.

I am a voracious reader, and the gas pumps here in the south have both formulas posted on the pump... so I suspected that just good ole 93 octane would work just fine. That has been backed up by the performance of my bike so far on a steady diet of the 93 octane without a single ping or knock.

That being said, if you use a higher octane than is needed you are actually robbing performance from the motor as the lower octane fuel is much more volatile and contains more energy per unit of measure.

Bud

  • wrenchbender

Posted February 04, 2005 - 06:29 AM

#9

Another good source of information--VP RACING FUELS.Go to their website-click on FUEL SPEC SHEET-click on OCTANE NUMBERS.Very good reading for octane explanations!

  • BIGMatt

Posted February 04, 2005 - 12:44 PM

#10

That being said, if you use a higher octane than is needed you are actually robbing performance from the motor as the lower octane fuel is much more volatile and contains more energy per unit of measure.
Bud


That is only sort of true. You'd want to use the lowest octane rating possible with out getting pinging or knocking. But because the flame front, or flame spread velocity is sooo fast during combustion that, unless you used (exaggeration) 150 octane in a 5:1 compression engine, you wouldn't notice any lack of power unless you are a hardcore pro racer.

I run 91 pump gas, and have only mixed with VP 100 Unleaded when riding at sea level altitudes or super hot weather.

  • dirtguy

Posted February 04, 2005 - 01:56 PM

#11

well the Yamaha shop mechanic said DON'T use leaded---the bike is engineered to run unleaded

would the lead react with the titanium valves adversly or build up on the plug electrode




 
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