Bike shuts off, only on hard acceleration

[Bhawkins854]

My dog has had a problem with this for a few months now. It runs fine until I whack the throttle hardd and it shuts off. Starts as if nothing happened, I do have tank liner breaking up but not too much, I added in line fuel filter and there isn't any deposits on the screen. Seems like fuel but why does it start so good after it dies? Could it be electrical ?

 

[KaptinAmerika]

Does All The Electrical Shut Down OR Does It Just DiE For Lack Of fuel

 

[Bhawkins854]

All the electrical remains on. I've seen postings on here about it, just wondering if chunks of tank liner will really make the bike die? Like i said its only when it's full throttle, like my accelerator pump won't hold up, just had xxx carb done and it was doing this before as well

 

[chacha]

Sounds like the accel pump needs adjusted. Try closing it off to take it out of the circuit and verify that wacking the throttle doesn't cause it to die---should have a big pause thou.

if so, then it's gotta be the accel pump. lots of information here and on the S&S website to set that up all proper.

 

[Bhawkins854]

So maybe I'm throwing too much fuel at it? Sounds like that could be true, xxx does a mod to the accel pump that squirts a thick stream of fuel instead of the stock fan type spray. Ill have to take youre advice and turn the pump way down and see if it goes away

 

[ground pounder]

It could be that when you hit the throttle you are pushing all the crap in your tank to the screen and when the bike shuts down you are not pulling any fuel and the crap falls away from the screen. Just a thought. Good luck !!!

 

[Peckerwood]

No expert here, but first pull the petcock off and clean and inspect if your liner is dissolving. Super easy, but a pain in the ass. How about that fuel filter? Sure it's passing enough gas as your carb demands at WFO? Then I'd try carb tuning. see the S&S website, my carb seems to need a lot of attention and fine-tuning to function at it's best.

Sven, let's hear it as only you can/

 

[Bhawkins854]

I have already pulled the peacock off before and there was tank liner stuck to it. I tried to clean the tank but I couldn't get it all out. Chances are it's still the problem. Too much fuel, not enough or electrical which I don't think is the case. I bought the 50 dollar fuel filer that say it will pass 6 gal a min so i hope it's not restricting flow. I think my best bet is to bring the tank in and have it professionally done

 

[Sven]

It runs fine until I whack the throttle hard and it shuts off.

I'm no expert so I'm going to go for door #1 I whack the throttle hard, it runs fine before that, but for some reason, I can't tell if it's fuel or whacktricks?

Starts as if nothing happened

I'm no tuner, but if you go jetting the bike all up, how come you think it's all rich or lean and it starts so well, whacks so well up to a point, right?

I added in line fuel filter and there isn't any deposits on the screen.

So far, scratch the liner. If it was fuel it would be all bubbles and the flow would show, but it does not seem the case. Starts too easy. Will take fuel but something or some transition is disrupted.

Seems like fuel but why does it start so good after it dies? Could it be electrical?

That's watt or where I'm going.

1. Starts too easy:
a. Not coil
b. Not timing
c. Not carb

2. Dies @ WOT:
a. Are we a computer bike?
b. Do we have sensors?
c. Do we have backup?
d. Do we know our low/mid mid/high transitions?

3. The method:
a. Low/mid mapping is one revolution short of...
b. ... Mid/high mapping.
c. This is the nature of the beast so my guess is computer related and/or sensor but hard to imagine is the beast and that sensor.

I need to see either a parts manual or a shop manual so I can tell who and what jobber is used and where? Right now I am after the main box, but without knowing more sensors than a cam sensor on this bike, we have vacuum assist anywhere?

I.E., The Method.

 

[Bhawkins854]

I didn't do a very good job of cleaning the tank liner out last time. Pulled the tank and petcock last night, more chunks than last time, bunch of them were stuck to the screen. Im dropping it off today to get it blasted and re-lined.

 

[Bhawkins854]

Seven no cam sensor, only a crank sensor, not too many sensors on these bikes. I dont see what kind of electrical problem would make it die WOT? I know these bikes have lots of EHC issues but only during WOT? This tank liner issue needs to be cleared up, then I check my carb adjustments and fuel again, then I check electrical..

 

[Sven]

Bhawk, believe me, you are on the worst ride is to detect who it is? They are so close and act like each other, correct? That's the confusion. So since you are close to the ride, we have a flap of tank coat that will cover the petcock and starve the bike? That sure sounds like a variable, but how could plain old gravity [down] a petcock cause something like vapor lock?

Are you saying that if you accelerate hard, the coating is going to cover the petcock screen or if they use a plain old tube exposed, then the sloshing happens to uncover the tube/screen upon instant start up each time? Never once would the flapping of the coating just hang over the petcock tubing and stay there?

So the deal now is:

1. I need to set a timing light on my spark.
2. Aim the light at me, tape both the trigger on and the body on the bars somewhere.
3. I am going to WOT the throttle past that rpm range or I know the area it will sign off at so I now watch if it [is] spark that drops out of the loop, or spark continues and my coating covers the petcock or say I have a fuel issue with the flicker of the timing light still happening.

It's either/or... Make sense?

 

[Sven]

Self-Powered Inductive Timing Light | Mechanics Tools Warehouse

Something like a self inductive timing light would do.

 

[bearman]

It is absolutely electrical problem. You never get an instant shutoff with fuel restriction.
sounds like you have a short somewhere. Is your battery strap holding the battery good and tight?

 

[Bhawkins854]

Hopefully this photo uploads. Went through all electrical connections on the bike. Found this female pin had pulled out of the connection to my right side handlebar control. Under further investigation the black wire is the ground for the entire circuit board for the run, off start and turn signal. Must have made contact until the bars vibrate the connection loose.

 

[francoblay1]

Hopefully this photo uploads. Went through all electrical connections on the bike. Found this female pin had pulled out of the connection to my right side handlebar control. Under further investigation the black wire is the ground for the entire circuit board for the run, off start and turn signal. Must have made contact until the bars vibrate the connection loose.

Is your problem sorted now?

 

[reloaderbmg]

fix the tank first, then retest.!!!

 

[Bhawkins854]

My tank is getting re-lined right now, I should have it back by Friday so I can test it out! I would have to imagine without a good ground to the circuit board that contains the run switch and off switch, there's a good chance it is shutting the bike off intermittently. Im not exactly sure what would happen when that ground wire connection pulled loose? The run switch is what sends power to my coil and ignition so that could be affected, or I suppose it could be telling the bike it needs to turn off as well? I do appreciate all the advice guys!

 

[Bhawkins854]

Yes this was most definitely the problem. Glad to have a place where I can get good information. Couldn't be happier that this problem is now resolved!

 

[francoblay1]

Yes this was most definitely the problem. Glad to have a place where I can get good information. Couldn't be happier that this problem is now resolved!

:2thumbs: