[2PLY]

funny cause i use 91 octane gas .....

Ah HA! I didn't catch that detail the first time reading it... 91 octane? That's what they pump in high altitude locations. We have 92 where I live. :thumbsup:

[Dan Williams]

I'm sure that the specifications for avgas are on-line somewhere. My guess is that they are mainly concerned with consistancy and compatibility with current equipment rather then performance enhancement.

After years of using pump gas with various degrees of success I discovered the problem with it is inconsistancy. Even with supposed "good" gas like Sunoco Ultra. After getting a particularly bad batch and having the bike cough and die 3/4 of the way up a rock slab and sliding backwards to plant tender bits on a tree stump I swore I'd never use pump gas again.

Since I've been using race gas my bikes haven't shown any variability from batch to batch. Roll on the throttle and they just go. That doesn't mean I don't have the occasional bad running day from a blocked jet or fouled plug but the fuel is now taken out of the equation when I need to debug a bad running bike. I can also let use last year's gas without a worry and when I take a carb apart I'm not greeted with corroded internals and that jellied goo that forms when the pump gas with it's cheap additives sits too long.

The price difference isn't really that significant either. I'll spend more fueling the truck to go to a couple of events then I'll put in the bike for a whole year. Well worth the peace of mind I get when I hit the throttle.

[BlackSCRunner]

So I went to Sunoco in Westborough MA today, and yes they have cam2 110 octane...but they are closed on Sunday! :(

[redrider7202]

LOL! that sucks! but atleast u know where to get it now

[ThatsA5]

So I went to Sunoco in Westborough MA today, and yes they have cam2 110 octane...but they are closed on Sunday! :(
They also close early on weeknights....I think 8pm.

[2PLY]

Well, after I get my 04 - 300 Pro GG dialed in and some time in the saddle with this 1 mm head spacer, if it pans out, I might just do it to the Raga too if I can run straight Premium 92 Octane. There is plenty of power with the spacer in the 300. Don't even notice the difference.

Anyone know if adding 1 mm to the squish area between the piston and head is going to cause any real problems?

[Dan Williams]

It shouldn't have any negative effect if you're OK with losing a bit of power. All it's going to do is lower the compression a little. Engine should run a bit cooler. Less stress on the mechanicals.

[CRM114]

I didn't read through the entire post so forgive me if this was already stated.

Any general aviation airport should have high octane fuel, and there are more of these airports around than you might think. Some people have said AV gas has other additives that cause problems but I've been running it for years with ZERO issues. Sometimes I mix 50/50 with 93 Octane pump gas, sometimes not. Bike seems to run the same either way. Oh, and it smells wonderful out the exhaust pipe.

John

[Smacaroni]

While this isn't trials related, my street bike gets a bad detonation condition sometimes..
It's hot, say 90 degrees, I'm running cheap 87 gas.
I'm heading down the highway, the bike has been running at 80 mph for a half hour and out of the blue it sounds like my engine is being pelted with shotgun pellets and loses power.
The only thing I can do at that point is back off the gas cause it won't run above 3/4ths throttle without more problems.
The guessing part on my end comes from believing that if I mix it with Auto Fuel, I'll get a combination of both, higher octane and a little faster burn ability. Something inbetween the two. I could be wrong there, but what I'm SURE of is the quality of the fuel itself. :thumbsup:Let me shed some light on this.
Most people don't realize it, but your average gas station that sells multiple octanes of fuel only have two or three tanks.
Tank 1: low grade
Tank 2: high grade
Tank 3: diesel.

So how do you get "mid grade"? You mix them together, the correct ratio of 87 and 93 will produce 89 or 90 depending on what the station owner wants to sell and charges appropriately.
If you don't believe me, go to any multi-grade pump, look on the side, there are two odometer looking read outs, one will say "high" and one "low".

You're doing the same thing that gas stations and blending stations have been doing for years.

[2PLY]

.............
You're doing the same thing that gas stations and blending stations have been doing for years.

Yes, I'm mixing 130 octane with 92 octane hoping to get something close to or above 100 octane, EXCEPT that I'm not mixing two different auto fuels. I'm mixing AVGAS and Auto fuel and I know that AVGAS is formulated for a different environment that includes high altitude, cold temperatures, constant engine loading in engines with extremely large pistons running at or below 3,500 RPM and in aircraft that are often stored for months at a time. So I'm sure there are additives to preserve and protect the fuel in storage, but I have no proof that they are beneficial or harmful or neutral in non-aircraft situations.

To give you an idea of what extremely large pistons means, the Lycoming 160 HP 4 cylinder engine has a cubic displacement of 350 cubic inches and the 6 cylinder engine used in the Cessna 182 is 500 ci !!!! 500 ci for a 6-banger!!! Blowing or burning holes through the pistons is one thing they harp about in your flight lessons. Bad Bad BAD!!

I use it, but I accept whatever risk comes with it and over the years (35) I have not identified any negative issues except for lead build-up on the spark plug with the older high lead AVGAS in my Trials bikes (the new AVGAS is Low Lead). But with the slow burning properties, I've heard (never experienced) that in high rev engines, the gas is still burning on the way out the exhaust port and can burn valves in 4-strokes with possible over-heating in all high rev engines. But then again, I'm not running straight AVGAS.

I'm still waiting to hear the details of the additives and what they do positive and negative. I've also heard something about a different "vapor pressure" for the high altitude operation among other terms. Use at your own risk, if any. But after 35 years and now at $4.00 per gallon versus almost $8.00 for "race gas", I'll stick with it for now. :thumbsup:

Sorry for yet another long Gas / AVGAS post. Hopefully I've made my position with some facts and questions clear. I'm not telling anyone to use it, I'm just relating to you what I have been using and with my limited knowledge why. I've heard good and bad but nothing from the Chemists that know the details. :thumbsup:

[Smacaroni]

$8.00 a gallon for race gas? You're getting off lucky, here it's over $60 for a five gallon jug. But the metal VP C-12 container is cool.

As far as what additives do what, if you asked me 12 to 13 years ago, I could probably tell you some and send you literature from Sunoco for the others. Now? I don't remember.
I get the concept of slow burn fuel. If you're spinning the engine all day at 12,000 RPMs, I'd put money on it that you're going to do bad things to your exhaust valves/power valve and head pipe. In a two-stroke application, the most extreme theoretical complication I could see is still burning fuel igniting the intake charge that has entered the chamber which is then forced back into the cylinder.
That's the most extreme and I think everything would have to be absolutely perfect for it to happen. What would happen after that? I don't know. Probably either blown head, head gasket or bent connecting rod.
I personally wouldn't worry about it.

I think 35 hours of actual application without problems would be a testiment that it's harmless, 35 years is excessive data.

The chemists are few and far between, most are sworn to secrecy so you're not going to get much out of them.

[Dan Williams]

If you run pump gas there's a lot of variation brand to brand and even batch to batch as it is changed winter to summer. Also consider it is now optimized for fuel injection systems as far as things like vapor pressure are concerned.

Overall I think there's way too much angst spent on this. The info's out there. Go find a fuel that works well within your budget and use it up.

[2PLY]

..... 35 years is excessive data.

The chemists are few and far between, most are sworn to secrecy so you're not going to get much out of them.

Thanks, I've been happy with it, but just can't give anyone any hard data why it works or doesn't so I'm reluctant to recommend it to people.

One interesting thing I read lately on an aviation site was a discussion about alcohol in the fuel. Seems that since some aircraft have received certification to burn auto fuel, there is pressure from aircraft owners and the FAA to prevent alcohol from being added to the Premium Auto fuel. If alcohol is added, the FAA will not allow it to be used in aircraft.

I have asked gas station owners about this and some have said that's true and that the premium grade doesn't have alcohol and that if it does, it has to be labelled on the pump. Problem is, that most pumps now can pump multiple grades and so they have the warning label on the pump, but they don't say if it's all grades that have it or only the mid and regular blend. :excuseme:

Regardless of whether I use AVGAS or not, I want to avoid any alcohol blended fuel if possible.

[Smacaroni]

I would assume that if the pump says "fortified with 10% ethanol" that all the grades at that station contain ethanol.
If it says "may contain 10% ethanol", I'd bet that the 87 octane is E10, the 89/90 is E5 and the 92/93 is gasoline. HOWEVER! I wouldn't use any of those pumps if I were putting it in a plane. And I don't know the whys and wheres of ethanol in aviation, I'm simply saying this because it's not recommended and planes have a three dimensional "sphere" of disaster, where cars tend to have a unidirectional line of trouble.
FWIW, I have nothing against ethanol, E10, E85, E95 or E100, there's just too much to go wrong in a plane.
If I were buying gasoline for aircraft, I'd buy from someone who advertises "no ethanol in our gas".
The public's perspective on E10 is really screwed up right now, I don't remember any big to do about it back in the early 80s when "gasohol" was common in our area. From my auto/motorcycle logs, I've noticed no significant change in performance or gas mileage with E10. The last two years I've logged at least 10,000 miles/year on the motorcycle alone I've missed two or three fill-ups in the log and that's it.
Having said that, I'll reiterate that when it comes to planes it's a different animal and I wouldn't do anything that's advised against ever.

[FESTER]

that would be funny to listen to habib betyourbooty try to explain gas ,'but if you buy a 32oz slushy i will throw in an incense burner':banana: Thanks, I've been happy with it, but just can't give anyone any hard data why it works or doesn't so I'm reluctant to recommend it to people.

One interesting thing I read lately on an aviation site was a discussion about alcohol in the fuel. Seems that since some aircraft have received certification to burn auto fuel, there is pressure from aircraft owners and the FAA to prevent alcohol from being added to the Premium Auto fuel. If alcohol is added, the FAA will not allow it to be used in aircraft.

I have asked gas station owners about this and some have said that's true and that the premium grade doesn't have alcohol and that if it does, it has to be labelled on the pump. Problem is, that most pumps now can pump multiple grades and so they have the warning label on the pump, but they don't say if it's all grades that have it or only the mid and regular blend. :excuseme:

Regardless of whether I use AVGAS or not, I want to avoid any alcohol blended fuel if possible.

[FESTER]

ok you guys, my bike runs fine on pump gas, even on donner summit,but once in a while when im feeling wealthy i use vp race gas, pretty f-en simple!right?so lets go to chemistry central and discuss this further!best place to buy it?sam kinnison....................a f-en motorcycle shop!!!!!!!!!!!!but i dont like the red stuff cause then i lose that bitchen blue color!

[2PLY]

On Donner Summit, you could run Regular unleaded... The higher the altitude, the less octane you need. Where were you when that was pointed out?

[BlackSCRunner]

Wow, lots of good info here. I have now located the Sunoco that sells 110 CAM2 as well as a couple small airports close by, but I have not yet checked if they sell gas, or will sell to me in small quantities.

On another note, I am interested in these head spacers I keep hearing 2ply talk about. Do they make these for my bike (BETA REV-3) and if so where do you buy them? I'll be honest, the bike has more power than I need at the moment, so the ability to run lower compression, easier kickstarting, and as a bonus also run standard 93 pump gas seems kinda nice to me :) I figure if I ever feel like I'm lacking in the power department in the future, I can always remove the spacer!

One more thing: regarding this VP race gas, if it comes in a nice metal container I think it might be worth it to buy a 5 gallon jug, use it up, then re-use the container. Where can you buy this stuff? I have checked at the local bike shops...no-go.

[Smacaroni]

My mechanic sells VP C-12 in bright blue 5 gallon cans. I managed to score some pre-mixed 32:1 off CL for free, however you can expect to pay $60-70 per five-gallon can.
OTOH, I wouldn't be surprised if you leave this unattended at a track, or more specifically on your trailer at a trail that someone is more likely to steal it, even if it's only got 87 octane pump gas in it, just because they think it's expensive. So take reasonable precautions when you leave it unattended.

As far as the general public, or I should say general thief is concerned, I'd bet they'd be less likely to steal it since it has no perceived value to them. The container looks like it could be farm chemicals. Around here, a company called "Valley Proteins" is who you call when a cow dies, so the VP logo is similar as well. I don't know how far or common Valley Proteins is outside of my area.

[Dan Williams]

See the drawing here.

http://www.newenglandtrials.org/rev3_2t_04_motore.pdf

There's basically two simple ways to do this, use an additional base gasket under the cylinder or use another head gasket on top of cylinder. Base gasket slightly changes port timing. Head gasket is a little more straight forward. Ron Commo can get you any parts you need. Daddy Ron's not only the importer but the best source of Beta info that isn't in Italian.

RCS Racing/BetaUSA
Rt #7
North Ferrisburg, VT 05473
Tel: (802) 425-2081

One thing that I find is a problem for a lot of new riders is they don't have their carbs set up properly. If the response of the engine is not linear due to poor jetting its very easy to attribute that to a motor that is too powerful. One of the reasons I love my carbon fiber reeds is they smooth out the power curve in the low RPM and make for very tractable engine that still jumps like a scalded cat when you whack the throttle.

The other trick if you find the bike is getting away from you is to slightly retard the ignition timing. This has roughly the same effect as the extra head gaskets causing the engine to not burn all it's mixture at the optimum time due to a delay in the start of combustion. Using extra gaskets lowers the gas pressure in the combustion chamber which slows the flame front so again not all the mixture is burned at the optimum time. Both of these methods reduce the efficiency of the engine which will make it run cooler as well.

Just one other thing to check is make sure you have a black throttle tube. The white throttle tube is faster and takes some getting used to.

[BlackSCRunner]

Just one other thing to check is make sure you have a black throttle tube. The white throttle tube is faster and takes some getting used to.

My throttle is aluminum in material and color. Not black or white plastic. :thinking:

[2PLY]

.....

On another note, I am interested in these head spacers I keep hearing 2ply talk about. Do they make these for my bike (BETA REV-3) and if so where do you buy them? ............


As far as I know, they were only made for Gas Gas and I believe one of the sources comes from the U.K. If you can't find info on them, you might give Adrian Lewis a call at LewisportUSA. That is where I bought mine and I know he gets them from some custom source. He should be able to find out if anyone can.

[Dan Williams]

OK that's no help. Apparently there are two versions of the aluminum Domino throttle, fast and slow. Which one you have I can't tell without grabbing and twisting it. The slow throttle is almost impossible to get full throttle without really twisting your wrist way out of shape. The fast throttle is essentially a 1/4 turn beastie. Most new riders will find it easier to deal with the slow throttle.

[redrider7202]

so fast is a normal bike?

[1992yz125]

correct

[redrider7202]

no wonder i think the thing is tame... what is full beans normally is like half way. actually i just noticed this same face earlier today. i twisted the grip on my dad's bike and i thought a carb was sticking since it was stopping so fast, so i went to my bike, same thing, 1/4 turn or so... i went to the beta and it just kept turning

[Dan Williams]

Typically Betas come with the slow throttle. My 08 is the first I've had that came with the fast tube. None come stock with the aluminum tube.

[BlackSCRunner]

Typically Betas come with the slow throttle. My 08 is the first I've had that came with the fast tube. None come stock with the aluminum tube.

So I looked through the parts box and the alternate throttle I have is all black and says beta domino. Maybe I'll try it to see if it's any different. This is the only trials bike I've ever ridden, so I really don't know what fast throttle is vs. slow throttle, although I'm guessing it's pretty apparent comparing the two. To me the throttle feels pretty sensitive. If it is the slow throttle that's on there now, it's safe to say I'll be sticking with it for a while ;)

Oh also, In the brief time that I rode today I *think* I heard some minor pinging, so I really need to get a metal fuel container and make a trip out to Sunoco during the week. Or look into that head spacer a little more.

[redrider7202]

That black one is the slow thottle that came with the bike. Easy way to check, fast thottle is like a normal bike... 1/4 turn. slow thottle is about a half turn

[ThatsA5]

I've been using the MSR fuel bottles for a couple of years now. I much prefer them then having a plastic gas can in the truck.Dan and 2-Ply,

Do you guys have any problems with those MSR bottles building up pressure if they are in the sun...or on a hot day?

Or do you fill them up to the top so they have no vapor space?

I have a lead on a bunch of bottles, well a few anyways, in the back storage area of a Army Navy store.