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LAG & LEAP (again)

97028 Views 333 Replies 70 Participants Last post by  Scott Hart
I realize there are already several threads on this. I am posting this one to see how many riders are experiencing this issue, and what you have done to try to resolve the problem.

I'll start:

My 750 does this all the time when low on fuel. It has been to the dealer 3 times, and the last time the tech was able to verify the problem. He said he is going to call Harley factory tech support regarding this. No word so far.

I called the factory 3 times, they plead ignorance, say they have never heard of the problem, and refer me to the dealer.

I have filed a complaint with the NHTSB. There are at least 7 others.

This bike is UNSAFE! A new rider could easily crash, or stall in front of another vehicle. Sales of the 500 and 750 should be stopped until this safety issue is resolved.
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WARNING: If you do experience this issue, pull in the clutch lever to avoid the sudden surge when the bike starts getting fuel again. I always ride with a couple of fingers on the clutch lever anyway. I have been riding for over 35 years.
I realize there are already several threads on this. I am posting this one to see how many riders are experiencing this issue, and what you have done to try to resolve the problem.

I'll start:

My 750 does this all the time when low on fuel. It has been to the dealer 3 times, and the last time the tech was able to verify the problem. He said he is going to call Harley factory tech support regarding this. No word so far.

I called the factory 3 times, they plead ignorance, say they have never heard of the problem, and refer me to the dealer.

I have filed a complaint with the NHTSB. There are at least 7 others.

This bike is UNSAFE! A new rider could easily crash, or stall in front of another vehicle. Sales of the 500 and 750 should be stopped until this safety issue is resolved.
My wife has been trying to learn to ride on the 500 after successfully taking a rider course. She has been having a lot of difficulty then the last time she was on it, still has not left the neighborhood, she took a spill very unexpectedly. She is frustrated and has not been back on the bike in a few weeks. It had the fuel light problems so today I drove it to the dealer to have that checked. Boy was I surprised. The throttle on this bike is extremely erratic. I wasn't sure I would make it to the dealer. I was suspecting it was some fuel delivery issue, or injectors, or maybe it really was low on fuel but with only about 40 miles of cul de sac riding that couldn't be! I am really pissed this bike threw my wife due to the erratic throttle and I was totally oblivious. Until today.
My wife has been trying to learn to ride on the 500 after successfully taking a rider course. She has been having a lot of difficulty then the last time she was on it, still has not left the neighborhood, she took a spill very unexpectedly. She is frustrated and has not been back on the bike in a few weeks. It had the fuel light problems so today I drove it to the dealer to have that checked. Boy was I surprised. The throttle on this bike is extremely erratic. I wasn't sure I would make it to the dealer. I was suspecting it was some fuel delivery issue, or injectors, or maybe it really was low on fuel but with only about 40 miles of cul de sac riding that couldn't be! I am really pissed this bike threw my wife due to the erratic throttle and I was totally oblivious. Until today.
If the low gas lag and leap issue caused this crash, I would file a complaint at NHTSA.
I've been experiencing the lag and leap issue from the very first tank. As soon as the fuel light comes on it starts cutting out and surging. But when I go fill it up as soon as this occurs, and it's not really that low on fuel, the problem stops. I've been meaning to take it in to the dealer for a month now, but difficult finding a ride home. Going to see if they're open this Friday after Thanksgiving and run it over. Has anybody that experienced this issue actually had it resolved and gotten a concrete answer as to what was wrong? If you shift through the gears quick enough and get going fairly fast the problem sorta seems to go away, but maybe that's a bad idea, lol.
My wife has been trying to learn to ride on the 500 after successfully taking a rider course. She has been having a lot of difficulty then the last time she was on it, still has not left the neighborhood, she took a spill very unexpectedly. She is frustrated and has not been back on the bike in a few weeks. It had the fuel light problems so today I drove it to the dealer to have that checked. Boy was I surprised. The throttle on this bike is extremely erratic. I wasn't sure I would make it to the dealer. I was suspecting it was some fuel delivery issue, or injectors, or maybe it really was low on fuel but with only about 40 miles of cul de sac riding that couldn't be! I am really pissed this bike threw my wife due to the erratic throttle and I was totally oblivious. Until today.

I have 3k on the xg750 now and have a suggestion. I let people ride it sometimes that want to know how it feels. If they are new I have them not use first gear. It is low enough gear when combined with the torque it can give a whiskey throttle jump to the bike to an inexperienced rider.

I doubt it is lag and leap as the fuel tank should be 3/4 fuel to 1/2 at worst.

My son is a beginner and has put most the miles on it. In the beginning he had some jumping on the start. I finally figured it out as a low end torque thing and had him riding 2nd through sixth. Once he got the torque pattern learned he went to using first gear.
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What City and State are you in Jefferson Gates Compton? I'm sure if a fellow rider on here was in the area, they would arrange to get you home. If you were local to me, I would give you a ride home and back if needed.
I've been experiencing the lag and leap issue from the very first tank. As soon as the fuel light comes on it starts cutting out and surging. But when I go fill it up as soon as this occurs, and it's not really that low on fuel, the problem stops. I've been meaning to take it in to the dealer for a month now, but difficult finding a ride home. Going to see if they're open this Friday after Thanksgiving and run it over. Has anybody that experienced this issue actually had it resolved and gotten a concrete answer as to what was wrong? If you shift through the gears quick enough and get going fairly fast the problem sorta seems to go away, but maybe that's a bad idea, lol.
Concrete answer? No.

The dealer replaced my fuel pump. I'm not convinced that I still have my stage 1 tune loaded on the bike either. I need to take it to a different dealer to verify that. I'm more than a little skeptical of the local dealer now - they took a month to "fix" the issue, but I'm still not convinced that its fixed... I haven't taken the tank down far enough.
I have 3k on the xg750 now and have a suggestion. I let people ride it sometimes that want to know how it feels. If they are new I have them not use first gear. It is low enough gear when combined with the torque it can give a whiskey throttle jump to the bike to an inexperienced rider.

I doubt it is lag and leap as the fuel tank should be 3/4 fuel to 1/2 at worst.

My son is a beginner and has put most the miles on it. In the beginning he had some jumping on the start. I finally figured it out as a low end torque thing and had him riding 2nd through sixth. Once he got the torque pattern learned he went to using first gear.
Well this is not the case with this bike. it was lurching and exhibiting erratic throttle behavior all the way to the dealer last night when I was riding it. The 500 doesn't have enough torque for us to use only 2nd gear.
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Well this is not the case with this bike. it was lurching and exhibiting erratic throttle behavior all the way to the dealer last night when I was riding it. The 500 doesn't have enough torque for us to use only 2nd gear.

Cool just wanted you to know what I found in case it helped.
Cool just wanted you to know what I found in case it helped.
Much appreciated!
Yes, I've been having this problem, and I've logged a complaint with the Safety Board. My dealership claimed to have not heard of this issue at all, and said they couldn't duplicate the issue once they're filled the tank. No kidding?

Very annoying situation. I'm hoping HD is following some of these posts, because I love the bike otherwise, and haven't been talking outside the forum about the issue, but I'm going to start thinking about changing that.
The bikes having the problems, were they made before a certain date ? I read that Harley had a few teething problems with the early bikes.
I want one of these bikes soooo bad. a 750 and I'm a novice rider at best. I've put about 8000 miles onto my little Honda Rebel and need to upgrade to something with more pow'r to ride on the Ft Worth and Dallas freeways...

This issue has prevented me from pulling the trigger and getting one. I'm watching this very very closely...

Thanks
Joe
My 750 has never done this to date. 3600 miles.
My dealer (Sacramento HD) called me today with news about this problem. My service writer called HD Tech and they are aware of the problem. HD is sending a fuel pump assembly and my dealer will be installing it next week. I will repost when I verify it is fixed.
Kudos to Sacramento HD for professionalism and proactive customer care!!!
My dealer (Sacramento HD) called me today with news about this problem. My service writer called HD Tech and they are aware of the problem. HD is sending a fuel pump assembly and my dealer will be installing it next week. I will repost when I verify it is fixed.
Kudos to Sacramento HD for professionalism and proactive customer care!!!
That is good news. My service writer was supposed to call HD tech, but I havn't heard from him yet. I'll be calling him today.

Thanks for your input.
Just got off the phone with my service writer. He told me the only thing HD tech recommended was to do a pressure check on the fuel system. So really no help at all. I am resigned to the fact that until Harley realizes/admits there is an issue, and does something about it, I'm just gonna have to wait it out.
As long as keep a good amount of fuel in the tank, the bike runs just fine. Put 100 miles on it today.
So I got my bike dropped off last week, they called and said they'd ordered a new fuel pump, and then got a call yesterday that it was ready for pick-up. I asked if they'd trying re-creating the problem after replacing, but they said no, HD told them to replace the fuel pump so that's what they did. So fingers crossed that fixed the problem. One thing of note, the manufacture date on the fork of my bike put it in the recall zone, but when they ran the VIN it had a different manufacture date that put it outside the recall. Only a month difference, but seems weird to me the dates didn't match.
I have also filed a complaint with NHTSA. I have had all guts inside the tank replaced three times. Fuel pump etc. Seems that the fuel pump is losing suction. The surging starts about 100 miles into a full tank. Gets progressively worse as the fuel level goes down. After 20 mile of this the low fuel light comes on. There is nothing wrong with low fuel light. My mechanic told me the fuel pickup tube is curling up off the bottom of the tank so the fuel pump loses suction when gas gets low. There is no fix, yet, for this problem. Now I use the first hesitation as my reserve fuel indicator and immediatly stop at the first gas station to fill up when it occurs.
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