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Sputtering and engine cutting off, 2002 S4

5K views 17 replies 4 participants last post by  Qomomoko  
#1 ·
2002, Monster S4.
Had been running fine, engine wise for quite a while as in years.
Did some electrical work, added a new horn and new wiring for improving headlight performance. This was done thru a kit from Easter Beaver. I AM NOT SAYING THE KIT DID THIS. I disconnected battery fully every time I was doing work.

Back to current issue. As shown in the video running first gear at 7k rpm and then start sputtering and finally dies off. I can keep her on by giving some gas and then she comes back. Same thing with 2nd gear but at times it stays alive.

The main switch (30A) fuse did give up about two years ago. I replaced it and looked at it when I was doing the electrical work recently. one end looked burned but the fuse was still good. Just and FYI.

Thanks.

Video link below, forgot how to embed

 
#2 ·
Your main fuse shouldn’t look burned. I’d replace it. Check that the wires coming in on both ends are fully seated and the contacts in the fuse holder are clean. Do a battery LOAD TEST.
Just checking voltage doesn’t indicate the battery’s condition. Coincidences do happen, but a more likely scenario is that your recent work has something to do with the bike not running right.
 
#3 ·
it was strange that it was burned; I did replace it.
I will check the stator and each phase. Will check cables and will clean my fuse box, it did look grimme.
I will unlpug the splitter with feeds the horn and the headlight kit ( and see how bike reacts).

I did keep the tank elevated/tilted for a while due to my work on the upgraded electrical kit and wonder if that loosed some grimme from the gas cap into the tank and clogged my filter.
My gas cap looks horribly corroded from underneath; wonder why and how to prevent this. Will do some deep tank cleaning and maybe even fix my low fuel light indicator.
I wish she would have run for some months so I could have enjoyed my brighter headlights and my new horn for a couple hundred miles.
 
#6 ·
Electrically, looks good, no stuff loose and cleaned the fuse box, replaced fuses, and then re-replaced the old ones LOL
Why?
Because I was paranoid and the new ones looked like there were the same (except for color); were obviously rated for different Amps thus different color.
Looked again today and saw it was mostly my in my head the above.

Back to the tank:
The fuel filter looks corroded/stained from the outside of the filter; it was dangling inside the tank and I positioned it back onto the holder.
A breather hose was broken; I cut it and reattached. Now the engine runs but dies within 5 seconds. I DO NOT UNDERSTAND.

Will keep looking at the tank and see what else might be wrong with the tank, figure next step is draining tank.

The breather hose is one of the two that hooks up to the top of the gas cap. Doubt it was this that was making the sputtering.
 
#9 ·
Answer these questions:Did you verify that the fuel lines between the tank and injectors, feed line and return line, are NOT BEING KINKED OR PINCHED WHEN YOU LOWER THE TANK?
also that FUEL IS GETTING TO THE INJECTORS.?
also THE BREATHER LINE IS NOT CLOGGED ?
 
#10 · (Edited)
I will post pics with which line is which (breather hoses ( one is overflow (breather #2) and other is a breather hose that partly seals when the fuel cap is closed(breather #1)))
Also the M(FEED) and the R(RETURN) (M is the furthest back in S4 02, I checked it by blowing on the outlet of fuel filter and seeing which spicket blew air)

my (what I am calling overflow ) is very very clogged.
I see how the tank not breather might not allow for fuel pump to suck as it would then create negative pressure IF the tank were to be sealed.
Also the clogged was probably caused by the corroded/degraded fuel cap and the corrosion going into the OVERFLOW Feed.

I will do pictures with labels but below is some pics to get a gist.

I would love to remove my low fuel sensor and attempt at fix it but seems partly stuck. Also the tank was more dirty inside than I would like..
within imgur I have a description of each spicket/nozzle.

First pic:
8 o-clock (overflow breather 2, 5 o'clock with rubber top overflow breather 1

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#12 ·
I see water droplets in the tank. The one you call breather 2 overflow line is the one that was broken, yes. Also clogged up with corrosion. The overflow drain. Therefore, when sitting outside or riding in the rain, any water around the cap will not be drained away and leaks into fuel tank. (tube under cap connection broken) After a while water accumulates bottom of tank. Fuel level sender should be easily removed but maybe stuck due to corrosion. This sender has to be removed to properly flush the tank, even tipping upside down, the recessed filler can stop fully flushing.
Could also have effected fuel pump, filter etc. your going to have to get them out and give them and tank a good clean, replace the filter, if any water gets into filter, it's hard to get out.
The water could have corroded the connections on pump and sender. Hope you have skinny arms, the pump is a bitch to remove if you can't get your forearms in there.
As for the vent pipe, try a length of wire, something like fencing tie wire, strong but flexible, work it through to push out dirt, then, if you don't have compressor, use a can of carb cleaner with the spray tube to flush out line.
Hope this helps.

ps. a picture of the Ducati guy who designed the in tank pump... :rolleyes:

224579
 
#13 ·
I see water droplets in the tank. The one you call breather 2 overflow line is the one that was broken, yes. Also clogged up with corrosion. The overflow drain. Therefore, when sitting outside or riding in the rain, any water around the cap will not be drained away and leaks into fuel tank. (tube under cap connection broken) After a while water accumulates bottom of tank. Fuel level sender should be easily removed but maybe stuck due to corrosion. This sender has to be removed to properly flush the tank, even tipping upside down, the recessed filler can stop fully flushing.
Could also have effected fuel pump, filter etc. your going to have to get them out and give them and tank a good clean, replace the filter, if any water gets into filter, it's hard to get out.
The water could have corroded the connections on pump and sender. Hope you have skinny arms, the pump is a bitch to remove if you can't get your forearms in there.
As for the vent pipe, try a length of wire, something like fencing tie wire, strong but flexible, work it through to push out dirt, then, if you don't have compressor, use a can of carb cleaner with the spray tube to flush out line.
Hope this helps.

ps. a picture of the Ducati guy who designed the in tank pump... :rolleyes:

View attachment 224579

jaja, thanks. Makes absolute sense and sucks.
I am surprised I have not seen evidence of water IN the oil when changing the oil filter.

The red flags were there and dissapointed I did not pick them up. I had already changed the fuel filter about 3-5 years ago and knew something was off due to all the corroded way the fuel cap looked. I am also surprised the 3 mechanics that I know that have seen the bike for one thing or the other never put the puzzle together :(

The water must be why the tank is powdery white and why the low fuel sensor has been so hard to remove; pretty sure I cracked the casing of the sensor and after 6 hours I am still am not done.
The breather is still clogged and am about 40% done; will try the carb cleaner. Will look into more tank flushing even thought I have cleaned it from 95% of the little debris inside. Have read of vinegar/water mix but I am not sure about using water jejeje

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#16 ·
That is the plan with, trying not to turn a blind eye.

For now, use a kit to clean and seal the inside of the tank
Continue to unclog the breather line ( will try carb cleaner to spray in side)
Will play with the low fuel sensor but will very likely order a new one; looks like when the low fuel light when out it was b/c it was cracked bu the pump wires were still good enough for the pump.

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#17 ·
That sensor looks well and truly shot. A common problem is the cables break inside the resin as they exit the bottom of the sensor. Crap design but at least the replacement comes with a decent nut. Be prepared to pay around US$250. Don’t bother trying to get a second hand one from fleabay, it will let you down.
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