Hi everyone in the Softail Forum…

I’ve describe this situation before but have not resolved it as of yet. I’m not even sure it’s even a problem.

I have a 2004 Fatboy with EFI, stage-1 upgrade. It has about 5000 miles on it.

I have noticed that when I am riding the bike in first gear, no throttle just allowing the bike to roll in a straight line on flat clear pavement, the bike will sort of pull or “slightly jerk” forward and then just roll forward in a sort of oscillating motion. Kind of a pulsating action. It’s like the injectors are turning on and fuel is cause the slight jerking.

I posted this a while back and someone said it might be chain jerk and my primary chain needed adjustment. I’ve have checked this and the chain is fine. The bike runs great and I have no problems at all other then this maneuver of allowing the bike to just roll along in first gear.

What I’m hoping for, is for someone to try this maneuver with a similar bike and configuration and let me know if they have the same results. My only other explanation for this is I may have a bad senor somewhere in the EFI.

Also, When I’m riding the bike I can here the EFI and the injectors, kind of a high pitch hissing sound. Funny that if I have the removable windscreen on I can here it more as well as the valves. And yes I have loud pipes. Cobra Pro 2 in 1…..

Thanks Mark

 

I have the same thing on my 04 heritage with efi. Had them check the chain tension on the 5000 mile check up and all was fine. They told me to just get use to it that it was the way my bike is. So no answer and nothing is wrong but still don't like it alot. But hasn't gotten any worse so figure they are probably right.

 

BassRock,

One other thing is that I have put a PowerCommander USB on the bike. After doing this I tried different mappings and found I could change the way it reacted making it less noticable. But I have never got it to go away completly. I took off the PC and get the same feel. So I think it is the EFI and maybe there is a way to get rid of it but I just haven't found the answer.

Mark

 

It sounds to me like the bike is just lugging due to low idle speed. When doing low speed manuvers, I use the friction zone in the clutch and the rear brake to control my speed.

 

oldgeezer,

I agree with you on this but it seems to be more pronounced in EFI bikes. I have a 14 year old EG and it doesn't have this problem at all. It's carb so I think that is the difference. When I choose mappings in the PC I have in my boy I can change the duration of the pulsing action. I've managed to get it to do small pulses that aren't as noticable. I guess I always thought EFI was better at regulating fuel and more steady.

Mark

 

You are probably right. I've only had carb'd bikes so I have no experience with EFI's. Sounds like it may be common amongst EFI bikes.

 

I feel that the problem you mention is appearant in all bikes given the right circumstances as you mention. It is the slack in the primary chain, even though it is adjusted to specs. there is still a small whip up and down under the circumstances you mention. On the other side of the coin, I feel that the HB 125 would just about eliminate the whip because of the way it is constructed.JMHO

 

i think tc is right i get it on both my sporty and my glide, my glide [injected] is far worse tho!

 

Chain tension will cause that. BUT you are on a bike that has a 4 inch stroke it was not designed to do what you are doing. You have a long stroke motor hammering away at the rod bearings. You are feeling each cylinder firing. You can do that with a short stroke engine, such as a inline or such but not on a big twin. Very hard on the engine, in fact hd has rejected engines that have had crank failures due to rider error. Not saying that is the problem but once you take a crank apart that has had the engine lugged it is a very obvious what happened.

 

when i saw the title of this thread, i wasn't sure i wanted to read it.