Potentially controversial fuel question

[JimmyR]

Sorry Steve - I meant the pilots went from 25 to 22.5. The mains are 130. I always get those confused because they are close except the mains have a "1" in front.

[Steve]

OK, that makes more sense. Actual numbers can't be compared to stock jetting on stock carbs, but it appears you are getting closer.

I don't know anything about your carbs, but I am going to assume there is a screw or two that will adjust pilot mixture?

On our older VM carbs, there is a pilot fuel screw on the bottom and a pilot air screw on the side that will be used to fine-tune the pilot mixture.

On the newer BS carbs (also called CV carbs), the mixture is preset by two jets, but the amount of the mixture that is admitted is adjusted with a screw.

If you have such a device on your carbs, you might be able to lean out your idle mixture a bit.

.

[bccap]

I use Chevron 94 whenever a station is available. It is ethanol free in Canada. When a Chevron station is not around I use 87 or regular. Haven't noticed any difference in running or idle.

[Steve]

I use Chevron 94 whenever a station is available. It is ethanol free in Canada. When a Chevron station is not around I use 87 or regular. Haven't noticed any difference in running or idle.

How much more expensive is the Chevron 94?

Why are you willing to pay that extra if you don't notice any difference?

.

[Badooka]

They say a fool and his money are soon parted!

[Steve]

They say a fool and his money are soon parted!

I wasn't trying to make any judgements, I really want to know the difference in price and why he is willing to pay it.

.

[1_v8_merc]

C'mon guys, everybody knows that premium fuel cleans out your engine!

[49er]

Possible oversight??

Not sure whether you're running RS34 or 36 flat slides. You said in your first post they were 35's, but I don't think they make a 35.

RS flatslides have a pump jet system that is manually adjustable. It is there to compensate when racers wack open the throttle on highly tuned engines at low engine revs causing their AFR's to suddenly lean off. You may find that your pump jet is too big and/or that the amount of throw is too great, causing the bogging richness you are experiencing.

You could isolate the pump actuation and tune accordingly, so you will receive accurate feedback from plug reads as to whether you're too lean or too rich for given jetting parameters.

Pump jets are a convenient method of correcting any lean spots experienced during aggressive pilot/needle jet transitions too.

[hampshirehog]

The big advantage to some guys in running higher octane fuel is that in some parts of the world with some brands the higher octane stuff (and it's not much higher octane - just a couple of points) doesn't contain any ethanol. And that can be a big advantage depending on what you are after.

It's got nothing to do with trying to clean your engine out or make your bike faster it's all about avoiding ethanol.

[SweetP]

I started using the Star-Tron additive a couple of years ago at the advice of the Motorcycle shop that use to be down the road, when I brought my L in becouse I it was running a little rough, he was right, after a couple of tankfulls using the Star-Tron additive the engine smooth ed right out...Now though more and more gas stations, around here anyway, are starting to offer ethenol free gas.

[Steve]

The big advantage to some guys in running higher octane fuel is that in some parts of the world with some brands the higher octane stuff
(and it's not much higher octane - just a couple of points) doesn't contain any ethanol.
And that can be a big advantage depending on what you are after.

I can understand that part of it, but can not verify with personal experience.

With three separate vehicles, my 850, my Wing and my van, I have tracked mileage and overall performance using various fuels. I have run a minimum of three tanksfuls of "regular" gas, noted the mileage and overall performance. Then I ran at least three tanks of "premium" fuel and noted any difference. Then I ran at least three tanks of "no ethanol" gas and noted the difference. The "premium" gas was not "ethanol-free", the "no ethanol" gas was "regular", 87 octane.

I keep a logbook in the van, so I can make notes about such stuff. In reviewing my notes, I can not find any differenece in gas mileage or performance, only that my wallet was a bit lighter, as both the "premium" gas and the "no ethanol" gas were about 20 cents more per gallon.

Maybe I happen to have three of those "one in a million" vehicles that are not affected by ethanol, but I will continue to use the cheapest stuff that will do the job.

.

[7981GS]

I use Chevron 94 whenever a station is available. It is ethanol free in Canada. When a Chevron station is not around I use 87 or regular. Haven't noticed any difference in running or idle.

With the much higher compression ratio in the 1100F and with the factory recommending premium fuel only,
you would be a fool not to run it.
The guys running the GSes with 8.8 and 9.2:1 compression ratio stock engines, should still be running at least 89 octane fuel but,
they are their bikes and perhaps they seldom if ever or never take them to the point of maximum spark advance anyway?

Eric

[bccap]

With the much higher compression ratio in the 1100F and with the factory recommending premium fuel only,
you would be a fool not to run it.
The guys running the GSes with 8.8 and 9.2:1 compression ratio stock engines, should still be running at least 89 octane fuel but,
they are their bikes and perhaps they seldom if ever or never take them to the point of maximum spark advance anyway?

Eric

Geez.... I didn't know that. I don't have an owners manual, just a service manual. Premium it is all the time. Thanks.

[7981GS]

Geez.... I didn't know that. I don't have an owners manual, just a service manual. Premium it is all the time. Thanks.

I'll see if I can't take some pic's and send them to you or post them here.

Eric

[7981GS]

1100G manual with 8.8:1 compression ratio...



GSX1100G manual with 10.0:1 compression ratio...



What ever you choose to put in your tanks, doesn't effect the longevity of my engines.


Eric