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Regular gas in LT

4K views 23 replies 8 participants last post by  Voyager 
#1 ·
Just coming back from Canada trip. Had a blast! If you are ever in Ontario, I strongly suggest you take Highway 129 north and Highway 17 South. Amazing!

Having said that, Highway 129, which has Canada's version on the Tail of the Dragon, has almost no gas stops. I almost ran out of gas. The buddy I rode with has a Harley Street Glide and he DID completely run out.

Anyways, we were fortunate enough to be fairly close to a secluded Canadian town called Missanabie when he ran out of has. It was only 54 kilometers away (30 km was gravel roads. I was really pleased about that) when my buddy ran out of gas. He rode with me to Missanabie where I got gas for my bike as well as gas in a can for his. The bad part is that there was only one choice for gas: regular. I filled her up a little more than halfway to make sure I could make it to the next civilized town. My LT immediately started running a little funny at slower speeds. Specifically, giving her throttle would sometimes give uneven results below 30 mph. When we got to Wawa, I filled her up with premium gas (91 octane). Since then, I have filled her up with 93 once and 92 once. She is still a bit unhappy at slower speeds.

The miles per gallon is no different than before and she is pretty normal at speeds above 30-35. She still runs well, but not quite like before. In this case, should I have the tank drained or will the lower octane gas eventually work itself out? Is there true damage that can be done from that half tank of regular gas? As always, thank you for your thoughts.
 
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#2 ·
If you have put in 4 or more gallons twice, then the effects of the regular should be down to almost nothing. I think the 05 is past the point where they increased the HP and compression a little and I think it required higher octane to keep from knocking but I have an 01 and still use premium only even if I could get by with mid or even regular as I believe i have heard some do.

You shouldn't have to drain the tank as it will continue to dilute and after 2 tanks, should be fine unless you got some contaminants along with that regular.

Unless you rode it for hours with audible knocking, you shouldn't have caused any damage as detonation would be the cause of any damage from the lower grade fuel. I have not heard my 01 knock as i have not been in a situation to require putting regular in it so I don't know how audible it is on the bike but I think you would be able to tell if it was though.
 
#3 ·
Thanks, Gordon. No knocking. Just semi-jerky acceleration at slow speeds.
 
#4 ·
That is interesting. I would have expected it to run fairly normally with lower octane but just knock under a load.
 
#6 ·
I'll try that. I'm home now and she still has inconsistent acceleration up until 2500-300 rpm. As soon as she gets to 3000 rpms, she is back to normal.
 
#7 ·
Does it do it when it's below 80°F? Have you cut the brown wire to switch to the alternate map? The stock fuel map retards the timing up to ~2.5-3k rpm when the temps are higher. That could be what you're feeling. Mine runs the same way unless it's below 80° (which doesn't happen this time of year in Texas). If you haven't already you can switch to the alternate map and see if that makes a difference. Just remember you will need to use premium fuel with the alternate map.
 
#11 ·
I've run regular grade fuel a few times with no ill effects, and actually my LT likes running mid-grade as good if not better than premium, go figure. Same fuel economy.

Does sound like a crapy tankful of regular.

I have a small gas station up in the mountains near where I live and they sell very little premium fuel and have gotten 3 bad tankfuls from them (water) in the bottom of the tank for my dirt bike and once in my Ducati ST4s.
I try to stay away from that station! As I NEVER fuel up there with the big Beemer...
 
#12 ·
Mark, I believe both you and I can get away with lower octane on our earlier LT's. There was a HP increase which also boosted compression requiring better gas but I don't remember what year that was implemented. I think it would include Patricks 05 in the upgrade though.

Still waiting on the report of temps in his area and if that has ever affected him before when it is above 80. As stated, it sounds like if could be the issue with temp and spark timing that gets retarded with temps over 80 requiring the cutting of the brown wire or the removal of the cat code plug.
 
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#15 ·
Another possible suggestion - if you're going off the beaten track where lower octane or lower quality gas may be your only option - consider packing a bottle of motorcycle octane booster (AMSOIL, Lucas, etc.) I've had good results putting Seafoam into my tank from time to time. What we should all dread and take action against is a mandate to boost ethanol content to 15 percent. No motorcycles or ATV's are meant to run on this and warranties may be voided. AMA has been strongly advocating against this for some time now.
 
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