What Gas do you Put In..?

[Anonymous]

Sorry Adam, I read your post wrong, I think you are correct, the older the engine, the lower the compression, thus lower octane

 

[DJones]

I agree with Nick! I have a `79 GS1000E and It runs fine on 87 octane.Brand makes no difference. Stop wasting your money and fix your raggedy ass bikes!

 

[AOD]

Why would a engine with over 20,000 mi. need higher octane than an under 20,000 mi. engine? The older engine should loose some compression thus need lower octane

wrong. engines do not lose compression ever, unless its by rings or gaskets failing. they require higher octane levels though, because of dirt, wear, and buildups on the valve train and piston. i dont know if i can find any info on this, but i've had a tour of the testing and engineering facilities at BP/Amoco headquarters located in Illinois here. They also did some presentations to us engineers about fuel technlolgies and needs. it is shown that engines require 1-3 points higher octane after 20,000 miles. buildup of gunk is the main reason.

as for gas refinieries...there are generic refineries, who buy crude oil from wherever, and process it, then sell it to gas stations. that's why it is cheaper then Amoco/BP, Shell of Mobil-Exxon.

i hope i explained things well enough,

~Adam

 

[Anonymous]

what gas

what gas

have tried running diferent octanes in my GS1000 but so the best of both worlds..price and octane I use the power plus mid grade from Chevron

 

[focus frenzy]

my 1000g used to run on 87 just fine but after the 1mm over bore it will only run well on 93 minimum, it detonates severely on regular now.

A item of note, altitude temperature and area will determine what works best, what works in the thin air of Colorado may not work down by the coast, you have to take into account altitude, say in the mountains the atmospheric pressure is 10psi, you compress that 9 to 1 and you get 90psi in the combustion chamber before combustion, so a lower octane will work. close to sea level the atmospheric pressure is over 14psi, so say 14psi compressed 9 to 1 will produce 126psi requiring higher octane.

plus, gas is formulated for different areas, the larger city areas are forced to use reformulated gas and despite having the same octane ratings it is defiantly not conductive to good power production.

 

[Anonymous]

Thanks Adam, for the explination. I'm not nearly as confused as I was before. I see exactly what you are saying "but" I thought in older higher mileage engines, valve jobs, ring replacement, and sometimes bore jobs were normal, because of normal ware. I see that in a perfect world none of these things would happen, but it just seems that in the real world these parts do ware, and it seems would have to lose some compression. Thanks for opening my eyes about the carbon build-up on top of the piston and in the combustion chamber, as small as the combustion chamber is I can see a few .00 of carbon could take up a larger % of the chamber than I had previously realized. If the carbon builds enough to cause the engine to need higher octane fuel, if the engine will be making more horsepower, higher compression with the same displacement should make more. I wasn't aware of generic refineries, I thought refineries were like battery & anti freeze mfg., very few huge companies that produce and sell to everyone else, Thanks to all, I really appreciate all the ifmo. that comes from this site

 

[Anonymous]

I have the origanl owners manual for my 1982 gs 1100gk and it says to use at least 85-95 octane. IT says if engine is pinging substitute another brand as there are differences between brands. I use 93 to make mine stop pinging.my bike has 56000 miles on it any thing lower it pings. gas is real poor in ILL. And I consider my GS is fine working order.

 

[joe.d]

My GS1150 runs like poop on Regular, in pings and splutters ...Premium gas seems to cure all of the problems.
it still pops on engine breaking...isn t that due to air getting in through the rubber inlets between the carbs and the engine?

the plugs are the perfect tone of coffee brown

though I do have a slight problem with the bike running fluffy between 5000 and 6500 revs Any Ideas?

.....But Im sure that the carbs need balancing im fairly new to this machine, and dont know of the history, I bought it from a motorcycle brakers who was originly gonna sell it off for parts

 

[MichaelHoward]

DJones,
Good for you. :twisted: My bike is not raggedy!! 8O

 

[Hap Call]

...it still pops on engine breaking...isn t that due to air getting in through the rubber inlets between the carbs and the engine?

the plugs are the perfect tone of coffee brown

You can get that popping from an exhaust gasket that is not completely sealed.

Hap
777.5

 

[Anonymous]

Here's another monkeywrench... Since the gov't has started to reduce the amount of MTBA in fuel, do we, or will we see an increase in alcohol/ethanol mixed fuels? Personally, I use 87 octane in my GK, but I'm concerned on whether we're gonna run into problems since ethanol is supposed to cause problems by running hotter.

 

[Anonymous]

That's a damn good question, one that some of us locally have talked about. My understanding is that the stuff will play havoc with our aluminum carburetors. Maybe someone can enlighten us here and develop this further.

Nick

 

[Anonymous]

I'll have to do a little investigation on this I think.

A thought off the top of my head though. Most carburetors are aluminum - autos, trucks, motorcycles, etc. Also fuel pumps, regulators, etc. If we are effected, then everyone is. I have doubts that they would screw up the entire country. Could be wrong though.

 

[lhanscom]

Aluminum and Contact with Ethanol


09.30.02 - Should ethanol be used with aluminum? The answer is not as simple as you may think. Ethanol experts agree that low amounts of ethanol (10% or less) may maintain contact with aluminum but higher amounts (70 to 85%) should not.

Ethanol, in its pure form, is an alcohol and therefore is corrosive with certain metals. High amounts of ethanol in fuel will corrode any aluminum in which it has contact. The corrosion will in turn contaminate
transportation fuel.

It has been brought to NEVC?s attention that some confusion has developed
regarding two recent publications supported by ethanol experts: The Fuel Ethanol Guideline published by RFA states that ethanol is compatible with aluminum and the Handbook for Handling, Storing, and Dispensing E85 published by NREL, DOE and NEVC states the opposite. Both publications are correct. The clarification between the two documents is to state that RFA focuses on low blends of ethanol at 10% or less and the NEVC focuses on
higher blends of ethanol.

Agreement was made between RFA Technical Consultant, Bob Reynolds, and NEVC Executive Director, Phil Lampert, that reference additions should be added
to the RFA document. These changes supported by SAE Technical Paper 940764; AAMA "Fuel Ethanol Compatibility Standards and Dispensing Equipment List for E85 Fueled Vehicles", August 10, 1995 GM R&D Paper, PR-448-March 1994 will
be included in the final issuance of the Technical Manual.

In conclusion, when using low level blends of ethanol such as E10, it is very satisfactory to store and dispense the product with aluminum equipment.
When using high-level blends of ethanol such as E85, the use of aluminum
should be avoided.

 

[AOD]

Ethanol is okay.

its mix in gasoline is controlled by the EPA regarding which area of the country you live in. for example, Chicago is required to have Ethanol in its fuel. Every gas you buy in Chicago has Ethanol in it, UP TO 10%.

gasoline makers like this because Ethanol is more volatile then gasoline...it raises the octane rating on fuels, so they can save money by starting with a lower grade fuel ~83 octane, and adding 10% ethanol to increase octane rating. ethanol is also man made, and cheaper. ethanol is good in moderation because it reduces the emmissions from our engines.

since i'm near Chicago, in the corn producing area's, farmers want people to use ethanol fuels. i have run my bike on the Chicago fuels with no problems...i dont forsee any problems for you guys either.

~Adam

 

[Anonymous]

Good information - thanks.

 

[redliner1973]

brand should not matter on our bikes. I go to Sheetz, Sunoco, Amoco, Shell, whichever is handy at the time. The mighty GK runs the same no matter what. Same with the four 850's that preceded it.

Fix your bike so you can run on the cheap stuff.

Cheapskate Nick

Well, Nick is right on this one. the GS is designed for 87 Octane. If you need a higher octane it is because there is something wrong. Usually carbon build up, or oil getting past the valve guides ( oil will really make an engine ping). Most gas is purchased from one major supplier in the area and distributed among several distributers in a given local. I have rode with a buddy who delivered fuel. He stopped at major competitors stations, dropped off, then goes to the local maji-mart and drops there. refills the truck and starts all over. A minute amount of carbon can raise the compression enough to raise octane requirements. it does not take much. this is why they say "may need higher requirement after 20K miles". the use of premium fuel in an engine requiring only regular will only accelerate the carbon build up. Whilst the BTU's of both the fuels are basically the same, gasoline burns slower as compression is lowered. In other words, the higher the compression, the faster it burns. hence the reason 87 will knock in a high compression motor. in a lower compression engine, the premium burns slower, and the piston moves alot of it out the pipe before combustion is actually complete. incomplete combustion = carbon build-up. it is a vicious cycle. If you take an engine that runs good on 87, and run premium in it, and put the engine on a dyno, it will have LESS hp than the 87. also, Detergency is the SAME FOR ALL GRADES of fuel. this is a Gov. mandate. 92 does NOT have more detergent than 87.
Now to the Ethanol issue. 1st off, ethanol in pump gas is not sufficient enough to be concerned with aluminum corrosion as much as it is to the rubber parts in the carbs. Bikes built today do not have this problem, but if your bikes carbs have not been resealed with todays gaskets, try and avoid it. Also, ethanol in itself does not make an engine run hotter. Ethanol is thicker than gasoline, and stuffing it in the same size jet causes a leaner condition. this in turn raises heating of the engine. BUT, ethanol runs Cooler during a burn than gasoline. so temps are equalised. Now, you have to take in consideration that ethanol also has less BTU's than gas. So more throttle is needed to produce the same amount of power. More throttle = more heat = hotter running. this also explains why alot of people complain that their mileage goes down slightly on ethanol, they actually have to give it more throttle hence giving the engine the impression it is working harder, therefore consuming more fuel. I hope this helps.... :twisted:

 

[dpep]

May as well throw my .02 on this. My original 850 owners manual, "Use only unleaded or low-lead type gasolline of at least 85-95 pump octane (R+M/2 method) or 89 octane or higher rated by the Research method".

I noticed a few years ago that in Florida in the summer in the heat of the afternoon out on I-95 with 2 up on my 850 I got pinging while trying to accelerate around intersate speed limit traffic. That was with premium fuel. The engine was high mileage but had an oil cooler. I know from top end work done around the time that there was minimal carbon build up. Heat and compression are both factors in preignition.

I understand that these might be considered extreme conditions, but my phlosophy has always been to provide for the worst case just in case. I use synthetic oil for the same reason.

I had a complete rebuild about 10,000 ago. Now that it is broken in I may try a couple of tanks of 87 during August to see if it behaves differently.

 

[Anonymous]

Hey, that 850 on your avatar looks great! I like that yellow.

I had an 80 GS850GT before the GK, my fourth and last 850. Great bikes they all were.

Nick

 

[dpep]

Hey, that 850 on your avatar looks great! I like that yellow.

Nick

Thanks, Nick. The compliment means a lot coming from the dean of the the shaft-drive school. The color is Corvette yellow. I agree with you about the greatness of the 850. I think it is only a 6th gear away from being the perfect all-around street motorcycle. Well, maybe a little more juice would be good too.