Race Fuel

[tmc3c]

What are some of the special mixtures of race fuel and pump gas being used for the 250 Pentons? You can tell it is getting close!!:D:D

Thomas Carmichael

[tlanders]

Thom,

I use 5 gallons of 93 octane pump fuel with 1 gallon of 110 octane race fuel, not aviation fuel, with 14.4 oz of Golden Spectro oil. The Golden Spectro bottle says that 5 gallons with 12 oz is 52:1 fuel/oil mixture. It actually is 53.333333333333333 etc. 14.4 oz is 6/5 of 12 oz. I have been timing my engines at 2.2 mm BTC with PVL ignition and no flywheel. I would love to hear from others how they are timing their bikes.

Teddy

[Gavin Housh]

Remember the good old days when you could get "high test" at the gas station. Wasn't that stuff 99 or 100 octain? Now if I want the high octain I have to pay $5.00 a gallon. Of coarse with our good friend Mr. Bush at the helm we are seeing the highest gas prices in history! Some people are expecting to pay $2.50 per gallon or more buy June, and that's for 87 octain. $5.00 for leaded 110 doesn't sound so bad when you look at it that way. All you Bush backers should think about what's important to you come November. If you want to have a job and drive a big SUV or truck you might just have to go the other way. I'll apologize now for voicing my opinions on this forum. I've just seen to many folks down on there luck with jobs and morgages/rent bills health care and pharmaceuticals food and the like. Something has got to give to many of our boys dieing in Iraq when we don't even provide heath care for our veterans. Giving away our Social Security to immigrants that never payed a red cent into it! Sorry, Sorry, Sorry. I promise I won't do it again. Gavin

[OUCWBOY]

Gavin,
I am sorry, but I really don't think this is the time or the place to voice your political views. I am not going to tell you mine. I am a vet of Viet Nam and the Persian Gulf.
On the subject of fuel. How many of you remember the SUNOCO brand of gas? You could use the dial on the side of the pump to select the octain and I think you could dial up to 103 or 105. It's been too long and I can't remember. Gas prices in The San Diego area are a few pennys less than the all time high here. If you run premium, you'll pay about $2.35 right now. I totally disagree with hte high gas prices, which are controlled by the oil companies, but look at the rate of ingflation for other things. A new truck in 1970 was an average price of about $3,000.00 and fuel was about 29 cents. A new truck today is close to $30,000.00 and at that rate of inflation, gas should be $2.90 a gallon.

Donny Smith

[firstturn]

Donny,
  Thank you.  I had forgotten about the dial on the side of the pump.  I always laugh when I think about the pump at the airport where you had to put a plane number on the record.  There was an old King Air that was missing a wing and I always used that number.  Just for the record I wonder how many others did the same.

Ron Carbaugh

[tomale]

Never did any thing like buying Aviation fuel for my bikes but I can remember spending 3 + hours in line to fill my van up with gas so that I could go to the races. Or how about parking my van around the corner and walking a few blocks with a jeep can to the local ARCO to get gas. The reason for the wait was because there was not enough fuel to go around [8D] And I was caught up unprepared. The race was 40 miles north at Altamont, ring any bells? so I got up at 3:30 and got in line to get gas. There already 40 cars infront of me and I wondered if I would get gas at all. the cool thing is that althought I had a bit of a head cold that day I won the second moto and finished 3rd overall. If was not for the blasted killswitch I would have done even better. It was the first race on my brand new 73? cr250
and my first moto win ever! Remember those red switches with the on off settings? I kept hitting it and killing the motor, very frustrating! I threw that thing away and between motos I put the kill switch that I had planned to install.... no more problems after that.
I have been told that they had transmission problems but I never did, which is funny because one of the main reasons for getting that bike was because the bultaco pursang that I had raced before always had trouble missing gears. After the Honda I got a Maico and I lost three transmissions in three races... The MC5... that baby is solid, it never gives my anykind of mechanical problems. Believe it or not It is still on the stock rings and piston.

Thom Green,I own and ride a 76 250 MC5 MX which I bought new.

[Dwight Rudder]

Unless you have radically bumped your compression or advanced the hell out of your ignition, You don't need more than 93 oct. I use 93 oct. with 8oz of Maxima or PJ1 octane booster per 5 gal. Never a problem.
If you want just a bit more. You can add a gallon of 100/110 Oct.LL Av Gas ( blue ). The lead in the so called Low Lead gas is much higher than car gas ever was and will bump the octane of the unleaded much greater than the sum divided by two.
Cher'o,
Dwight

Dwight Rudder
7 time ISDT / E medalist
8 time National Enduro Class Champion.

[desmond197]

I  use race gas in my Pentons and Golden Spectro 50:1 ratio. I use the race gas because it is consistant and does not have any additives that may screw up my fiberglass tanks. The cost is negligable as I  use about 40 gallons a year in my bikes.

[wildman]

I use pump 93 octane and 12oz of golden spectro for a 50:1 ratio in all my two strokes. I have found best results by mixing fresh gas the day of riding and dumping whats leftover into my lawnmower and chainsaw, ect. I found that my bike starts much better and doesn't foul plugs as easy. The pump gas today seems to lose its aromatics real quick, I hear a metal gas can is best to seal those in.
Your ignition timing should probably be close to stock, at least I've never improved on the factory engineering. You must use a dial indicator to exactly set it properly.           What kind and number spark plug do most pog'ers use in their pentons?

1975 250GS in Mich.

[Speedy]

quote:Originally posted by wildman

I use pump 93 octane and 12oz of golden spectro for a 50:1 ratio in all my two strokes. I have found best results by mixing fresh gas the day of riding and dumping whats leftover into my lawnmower and chainsaw, ect. I found that my bike starts much better and doesn't foul plugs as easy. The pump gas today seems to lose its aromatics real quick, I hear a metal gas can is best to seal those in.
Your ignition timing should probably be close to stock, at least I've never improved on the factory engineering. You must use a dial indicator to exactly set it properly.           What kind and number spark plug do most pog'ers use in their pentons?

1975 250GS in Mich.

And if you would use High Test gas mixed with OPTIMOL oil 100:1 you would even do better.
I do it for over 25 years,and I would not do what hurts me.LOGIC???
Speedy------>>>>>>>>

Helmut Clasen KTM
162 Hillcrest Ave
L9H 4Y3
Dundas Ontario Canada
Ph.905-627-5349
[email protected]
http://speedy_c.tripod.com
Sachs GP-GS 250-7A reeds
Zuendapp 125 GS ISDT repl.73
KTM 450 EXC Auto.03
Duke spec.Edit,1996
Adventurer 02

[wildman]

I've heard of people using 100;1 ratios, but when I think of the minute amount of oil to the rod and mains, I just can"t do it. What kind of wear have you experienced, Speedy. I remember some guys using Amsoil like that on their trials bikes, maybe oil today is that much better with the jaso rating.ect. Please tell me a little more about what you'r using and where to get it. It would have to be pretty special for me to give up my beloved Spectro! (Hi-Point)

1975 250GS in Mich.

[firstturn]

Dwight,
  You bring up some excellent points.  Before going to work for Honda I worked for ten years for Mobil Oil.  I had our motor lab test all the fuel and oils that I used.
  I did have higher compression (with no failures) and I did use different ignition systems.  On several of my bikes this was to change the ignition dwell angle and on certain bikes to do away with the rev limiter.
  I wouldn't recommend this to people just trying to do this by guessing.
  The other thing is when you were talking about the sum divided by two I am assuming you were talking about lead in the new form of chemicals and not lead by the old standards that was mainly used for protecting valve trains on 4 stroke engines?
  I know you have tremendous background in aviation and probably know that lead was introduced in the 1930's to properly lubricate the aircraft engines.  As they say there are no parking places at 10,000 feet.
  Great subject.

Ron Carbaugh

[Dwight Rudder]

No, I am talking old fashion Teraethel Lead. As used in Aircraft engines and formerly of auto engines to protect the valves. It had a secondary function of boosting the octane of the gasoline. 100/110LL has less lead than the older AvGas like 80oct. but much more than MoGas ever had. The Lead will boost the octane levels up greater than the sum divided by 2.
IE.: 93oct MoGas + 100LL AvGas / 2 = ( It doesn't equal 96.5oct.) More like 99oct depending on the quality of the original fuels.  I am suggesting using 1 gal of AvGas to 4 gal of MoGas 93oct to get about 95 oct. I also find that Maxima Super M works great and burns clean compared to Spectro. You can mix at 40:1. I find the engine also lasts longer than with Spectro mixed at 50:1. Spectro mixed at 40:1 is good but carbons up the engine. Speedy swears by Optimol at 100:1. I had been using a private labeled 2 cycle oil for Hirth Aircraft engines called Blue Max Aviation oil. The spec sheet reads like an Optimol comercial. It looks like it too. I ran some in my Hodaka a couple weekends ago , mixed at 80:1 with excellant results. I was too chicken to run it at 100:1 although that is what I ran in my WWI replica Nieuport 16. But the Hirth is a low rpm engine cruiseing at 4700 rpm. Max take off rpm is about 5500.  So you see my Hirth is a low rpm engine. The Hodaka 100B is a bit higher at 8,000. And it stayed at over 6000 rpm for 2 days.
Cher'o,
Dwight

Dwight Rudder
7 time ISDT / E medalist
8 time National Enduro Class Champion.

[firstturn]

Dwight,
  Thanks for clearing up your thoughts.  I used the mixing of gas since around 1973.  It works.  I appreciate your information on oils and mixtures.  I am on the same page as you with not using the 100:1, but my engineering friends and I agree to disagree.  I appreciate your view as a many time Champion.
  Speaking of your racing I ran across a copy of a picture of you in I believe France at the 6 day.  Do you remember one of your sponsors?  You had it on your bike[?].  How about the Red Dog Race Team.  Say Hi to your Bride and she is in our prayers.

Ron Carbaugh

[Dwight Rudder]

Yeah, I remember the Honda of Fort Walton Crew.  Wish we could get them to the ISDTR. They would have a blast.
Dwight

Dwight Rudder
7 time ISDT / E medalist
8 time National Enduro Class Champion.