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Discussion Starter #1 (Edited)
So I filled yesterday with 91 octane 'cuz that's all they had... and the bike noticeably started running like crap today. Sputtering/hesitating at anything under 1/4 throttle. Kinda sucked since today was my DMV skills test. I passed but had to keep it gassed and drag the rear brake through the circle sequence.

Anyway, not sure if it's the gas or what. Thinking I just need to go over everything on this bike anyway. Put 350 miles so far on her since I got it ~2wks ago, no problems 'til today (other than my previous post of backfiring/popping at high rpm's downhill coasting). Seems only change was the higher octane. I talked to the previous owner 2nite, he said all he ever did was change the oil. '05 with 2300 miles. Should I go ahead and just pull the carb, clean everything, lube everything, etc? Also no valve adj. was ever done on this bike yet... I seem to hear a bit of clicking, haven't dug into it yet. Certainly the chain needs lubed and whatever else. Any advice appreciated!
 

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Hmm. 91 octane just made my fuel too rich and rpms would stay high like crazy. Went back to 87 octane and fuel stabilizer and no problems since.
 

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I've ONLY ran 87 octane a couple of times and even then it was diluted with 91. 91 is my choice 99.99999 % of time. I'd check and adjust those valves. Mine was quite out of adjustment at 800 miles. Stupid question, but was your choke on?
 

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Discussion Starter #4 (Edited)
I've ONLY ran 87 octane a couple of times and even then it was diluted with 91. 91 is my choice 99.99999 % of time. I'd check and adjust those valves. Mine was quite out of adjustment at 800 miles. Stupid question, but was your choke on?
No such thing as a stupid question in my book..., but yeah choke was off. In fact it was hard starting this morning and if I added any choke it just died. Hit the starter & just a bit of throttle got it going, but the hesitation through 1/4 throttle stayed throughout the day. Not a HUGE hesitation but enough for you to really feel it while in 1st gear.
 

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I don't know about these pumps that share numerous fuels in one hose, how much is left from the previous pump grade?

Regarding popping, pinging and poor running, this could be a host of issues totally unrelated to the octane. Valves adjusted to speck, tank clean and free of crud and the petcock should also be cleaned. Pull the carb and make sure there is no crud in it. They can be mighty finicky and just a tiny speck can cause issues. When you put the carb back on it is imperative that both boot connections are an air tight seal. Once the engine is running and warmed up you then play with the pilot adjustment screw. I start at 2 full turns out from the fully bottomed point. This adjustment is probably the most finicky and a twist of less than a quarter turn can make or brake the throttle response. Too rich and your plug will be black and too lean your plug will look almost white. It should have a toasty tan color when properly adjusted. Blaming poor running on the octane of your fuel is meaningless until all other adjustments are checked. Last but not least, knowing your fuel provider is helpful. I don't use stations that have little traffic, the fuel could be old. I never fill up when the station is receiving a fuel delivery, this could stir up crud in the ground tank. An in line fuel filter is a very good idea as is a shot of fuel conditioner such as SeaFoam or Lucas in every tank.

GaryL
 

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It is easy to drain the tank. Do it. Check ALL the stuff GaryL suggests. Then, refill with 87 octane and a 2x+ dose of SeaFoam or "Lucas Deep Cleaning Fuel System Cleaner". I bet your tank screen(s) is plugged. Did you try switching to reserve just to see if its screen flows better?
 

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yea do what tony said first drain your tank and put the fuel in your car...it will dilute in there...fill with 87 then do the stuff garyl said...

this is from another forum i belong to...

"This might sound strange but something I have learned working 20+ in the petroleum industry. There are so many refineries and companies often get their supplies from the same vendor. There are additives and other items that will vary but the fuel source is the same regardless. What you should do is look for the station that has the highest amount of traffic and if you want to take it a step further, ask the manager when was the last time their tanks were cleaned and what cleaning rotation are his tanks on. Fuel sitting in tanks for a duration of time will do more harm to the quality of fuel regardless of the company sign hanging over the pumps. Ironically, there are times the higher premiums can have quality issues because there is less traffic at those pumps (depending on station and location) and at the end of it...you would be better off getting the lower grade because of the increased traffic going to that pump. Good station with a good tank cleaning schedule that is adhered to and a high volume of customers always going through their pumps...that is what you want to look for. Hope it helps."
 

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If the pump you got the gas from shares the same hose for all grades of fuel, then you got very little if any 91 octane. That hose holds about a gallon of what ever was pumped by the last guy before you get 'fresh' fuel through the pump, hose, nozzle and into your tank.

Could be you got bad gas with water in it. Try some seafoam in the tank and run it a bit to see if that dries out the water.

Oh yes, the last guy that pumped gas in that hose used diesel. :dispirited: Just kidding.
 

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Yesterday I switched to 91 octane and drove 75 miles. It ran perfect. I have a hard time thinking the 91 octane caused what you are describing, but who knows? I would drain it out and put 87 back in and see if it runs normal again.
 

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When you go to the gas pump you don't know what gas was pumped and left in the hose. Could a person drain the hose in a can before they begin their own purchase?
 

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It was crap gas OCTANE had noting to do with it and either did the hose
 

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Discussion Starter #13
Thanks for advice all. I'm gonna drain it all this wknd and clean everything up. I found it odd that just a change of octane would cause it to run like that. 'Bad gas' does seem a lot more likely. It was a Shell station, and they were out of 87 & 89, probably was really bottom of the barrel on the 91 that day too come to think of it.

I also went on a pretty long ride the day before over some pretty rough stuff, about 40 miles. The previous owner hardly had this thing off road... so I guess it's also likely I broke whatever minor crud loose and it made it into the carb or clogged the screen. Thanks for the advice all... will report back what I find.
 

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Any station that is out of 87 and 89 is a very bad sign! Who knows how long the 91 had been in that tank? I will tell any MC rider it is a very good idea to clean out the junk in your gas tank as soon as you buy a used bike. You never know how long it sat and you can't believe half of what the seller tells you. Chances are he lost interest in the bike and his only interest is to sell it.

Dump the tank in to a white 5 gallon bucket and you will immediately see the problems cause. Remove the petcock and slosh some of the dumped fuel around in it and dump that through the petcock hole. The lip inside where the cap is makes it real hard to get the junk out.

GaryL
 

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Discussion Starter #15
Thanks Gary, will do! It never dawned on me at the time re: the bad signs at the gas station, I just need a gal or so of fuel. Live and learn. I've wanted to go through this bike anyway since getting it, just been having too much fun riding it since the purchase! Fairly confident it sat a while since only 2k+ miles on a 2005... and he was a very older dude that was pretty honest with me that it sat a while the past year. Prior to that he only used it to go maybe a few miles into town and back, and seeing where he lived I believe it. One thing's for sure, I don't need to worry about how hard he rode it ;)

Very much appreciate the detailed advice! Gonna work on it this weekend.
 

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I bought my first TW, 1991 last year from the exact same situation. 71 year old guy who owned an RV camp ground. It only had 671 miles but sat a lot in a heated garage. Never abused and never saw rain or mud. The tank and carb were horrible but the rest was like showroom new. I found this site and asked all the exact same questions here. Once I cleaned the tank and petcock and put a filter in line I messed with the carb. Finally bought a brand new carb and the bike came to life with perfect manners. These are great bikes and pretty simple to figure out. If you do as I say you will be a very happy fellow.

GaryL
 

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Any station that is out of 87 and 89 is a very bad sign! Who knows how long the 91 had been in that tank?
not to mention if the 91 was low, water is more dense than gasoline so any water that may have gotten into the gas station tank would be at the bottom of the tank
 
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