What octane fuel do you run in your XS

[ddragon63]

35 + 35 = 70, 70 x $4 = $280......................

I think I'll stick with my XS at 30 MPG and about $50 a day max to have fun.

You can't catch 40lb fall Chinook Salmon from the saddle of the XS thou! All thou I have taken mine up on the Lewis River to go drift fishing.... I looked kinda funny rollin up the hwy with my chest waders on, and 2 poles bunge corded to the back seat and trunk.

with the price of gas we get the boat as close to where we are going fishing as possible now. The ford gets 12 mpg towing it. the boat get 2 to 6 mpg depending on river conditions, and how hard on the throttle stick I am that day. I'm glad I didn't buy the big block boat I was looking @ before I got this one. The 351W and Hamilton 770 3 stage pump suck enough gas pushing that 22 foot hunk of aluminum around. I'd hate to pay the gas bill on one with a 460 and 900 series pump

[Cuda 69]

a friend of mine(who works for a bike shop) told me,when I asked the same question,to run regular in my bike,the reason being,is when you burn high octane gas,it runs hotter.Having an air cooled engine you want it to run cooler,I suppose if you had water cooled engine,it would be ok,but what the h^ll do I know?

[ddragon63]

a friend of mine(who works for a bike shop) told me,when I asked the same question,to run regular in my bike,the reason being,is when you burn high octane gas,it runs hotter.Having an air cooled engine you want it to run cooler,I suppose if you had water cooled engine,it would be ok,but what the h^ll do I know?

Fuel School 101 (what I learned in engine performance classes 15 years ago)... you want to burn the lowest octane possible in a motor... the closer to detonation with out crossing that line the more power it will make, and the cleaner the burn. a modern Gasoline internal combustion engine only burns 70 to 80% of the fuel air mixture drawn into the motor. Now if you have too much octane it will not burn as efficiently. the unbruned fuel with create hydrocarbons which can build up in the exhaust and valves as carbon. theses unburnt hydrocarbons is what creates the Extra "heat" your speaking of as they can ignite thru exhaust heat. so technical speaking super in a motor designed for regular will actually burn cooler... as it is not fully combusting. if that makes any sense? But I understand what your friend is saying @ the end of the day it will actually create more heat. but its not that it burn hotter... put 114 octane race fuel in your bike and see what happens... your plug will foul out as it can't burn the fuel very well. Most people think of fuel in the opposite direction. Like you've added more fuel to the fire... where in fact you are changing the air fuel ratio richer. Take air away from the fire and it doesn't matter how much fuel you put to it, it wont burn.

Now with that all said My original post was to just get a base line of what everyone runs. with a comp ratio of about 8.5 to 1 a XS motor should run on 87 octane. My thought was with the 4000 to 5000 rpm it sees @ a cruise and being air cooled I was curious on everyone's thought an keeping more octane in the fire during hard load or off normal ambient temps. I see most have had good luck with regular... but it seems sometime people have had their bikes ping. Pinging is not good... it you can hear detonation it has already been detonating for a while and has now finally got mad enough to make a audible noise... but pinging can be caused by more issues than fuel octane. As Steve described earlier.. heat and load cause him some pinging. with an air cooled motor this can happen alot. If your passing 100 deg air across the fins of a motor that is already 200 degrees its not gonna cool well. Altitude can play in to this also. But if its 30 outside you can make a motor ping too as the air is denser and your over all air fuel ratio is now changed. This has always been the downfall of Carbureted motors. They are stuck @ 1 tuning level and can not self adjust.

I guess what I'm getting @ is you have to walk the fine line of what works for your bike and the conditions you ride in. I have ran a tank of 87 thru mine now in 50 to 60 deg weather and the plugs read REALLY lean. So untill it gets over 70 I will probably run 89 or 92. this sunday it will be 70 to 80 where I'm riding so I will try 87 again... and see how it goes. first sign of madness I will be find higher octane gas in a hurry... YMMV as always.

[Joab]

You need to take a breath after that there buddy?

Good info though!

[ddragon63]

You need to take a breath after that there buddy?

Good info though!

I took 2 beer breaks in that... of course I had to re-read everything I wrote to remember where I left off Just remember high altitude will act the same as high heat. less air (or bad air in heat) means more fuel in the air/fuel ratio. so I can see 87 in these conditions. but some may want to adjust to buying the higher octane while its colder or riding @ sea level... just my thoughts. use it or don't... I'm just not a fan of pinging a 33 year old bike with hard to find valves...

[Poprock]

I'm @ sea level, cool air here on the coast. Kong loves that cool air. Runing E-10 87, he loves it. I'm real impressed with the power he's making with 1 oz. of Lucas in the tank. A bottle of Lucas will treat 30 tanks of gas for me, so it works out the least expensive additive. Kong seems to really like cool air. Carbs are all stock jetting. He ran fine in central Oregon and up to Hells Canyon last summer too. 87 oct. the whole trip.

[ddragon63]

I'm gonna start squirting a Lil Lucas in old man every tank. It really helps everything else I own. I've yet to figure out how so little goes so far compared to other brand additives. But im not gonna think on it too hard

[CaptonZap]

I'm gonna start squirting a Lil Lucas in old man every tank. It really helps everything else I own. I've yet to figure out how so little goes so far compared to other brand additives. But im not gonna think on it too hard

Which Lucas product are you using? The upper cylinder lube, or the gas treatment?
Thanks, CZ

[ddragon63]

the fuel treatment with upper cyl lube... use it in everything!

[jetmechmarty]

I have some ethanol free fuel available to me. At some stores, it is only available in 93 octane (premium). I normally run 87 octane fuel, but if I can buy without ethanol, that's what I do. If the ethanol free is only 93, that's what she gets.

I also ride a XS650. It has a hemi head design. I always use 93 octane (R+M/2) in it.

[Bonz]

CZ, it's the fuel treatment, buy it by the gallon for around the low $30 range. Don't buy the small bottles (4-6 oz or something small like that) as they hit you for about $5.

I have a gallon of it in my garage, when you come down this way I'll treat your bike to a serving.

Yeah, that was my secret... I was running it in my XS for the Rally last summer and THAT'S how I turned such great fuel mileage... No I didn't run it the entire trip, but I did put some in at the start of the trip. I need to do an empirical study, per se, but everything in me says it helps at the tune of a couple mpg based on years of use.

[natemoen]

This the stuff you are talking about Don? If so I just found the gallon bottle for $21 locally!

http://www.amazon.com/gp/aw/d/B000FW...5666982&sr=8-1

[ddragon63]

This the stuff you are talking about Don? If so I just found the gallon bottle for $21 locally!

http://www.amazon.com/gp/aw/d/B000FW...5666982&sr=8-1

yes Sir... that is the stuff

[jjz28]

So, do everyone put about 1oz. of it in a full tank? I have been running 93 in Picky but I am sure "Picky" the PO probably ran the cheapest 87, so maybe i will go back to 87. I dont know why, i just thought 93 would burn better and cleaner so i put it in everything except my lawn mower. My camaro and cobalt ss actually call for no less than 92.

[jimbyjimb]

I only had one time when any of mine ever rattled on quality regular-grade fuel, and Don will appreciate this....

I was running across the Hanford Nuclear Reservation desert from Yakima to I-90 in blast-furnace heat on my '78 (this was in the early 80s) and had the hammer down trying to get somewhere where it was cooler. About 20 minutes into this high-speed run (two-up, towing my trailer), the bike started pinging if I tried to get more 90 mph.... I can't stress too much how hot it was. Finally pulled into the small town of Othello and I swear the temp felt like it dropped 30 degrees. As we were going through town, a time/temp display (in the shade no less) read out 101 degrees, so the temp out on that desert must have been over 120.... We stopped and cooled both the bike and us, and after leaving town never had any more problems; but we never ran in heat like that again...

The SG I rebuilt and sold last year ran fine on the local name-brand regular, including a full-throttle off-idle pull in 5th gear. I have had some issues in the past with off-brand fuel, but you get what you pay for...

Last year I was riding Seattle to Butte, 90-100 degrees. I hit Moscow mid day and my 11 was having trouble idling. Ran odd too. I stopped for twenty, bike ran fine. I decided to go back to Seattle because Moscow is almost perfectly halfway to Butte.

The bike started running like crap at below 3-4k about an hour out of Pullman on the way back to Seattle. I made it to a rest stop just east of Ellensberg and the 11 just gave up on me. I have AAA premium, so they towed me home. Next day I go out to check the damage, bike fires up like nothing. Ran perfect on a test ride. So then I was introduced to the evil, sadistic vapor-lock and promptly slapped myself for ruining an otherwise perfect trip by being a major ignoramous and idiot.

This year I'll be cooling those fuel lines. I'll make it to Butte or bust!