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Hi everyone, please help me before i burn this bike Ducati ST4S

I bought a new battery for it because the old one died. battery is fully charged, but still suffers to turn over. when i jump start it with my car it starts and all but then when i switch it off and try starting it with its battery it some times starts but even then its like by chance.

Battery is brand new and correct type as manual. but still having a hard time to turn over. any help will be much appreciated.
 

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Some threads that may be a good starting point (pun intended) for help:


 

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I still haven't fixed mine, i have stripped it completely down all covers off and tracing wire. and i have been through all these posts from others and i cant find the issue. i am suspecting its the charging system on mine. i start the bike the volts do NOT pass 13.5v while idling and revving high. so i suspect i have killed my new battery already through this bike. the charging system inside the engine is what i suspect is at fault.
 

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I still haven't fixed mine, i have stripped it completely down all covers off and tracing wire. and i have been through all these posts from others and i cant find the issue. i am suspecting its the charging system on mine. i start the bike the volts do NOT pass 13.5v while idling and revving high. so i suspect i have killed my new battery already through this bike. the charging system inside the engine is what i suspect is at fault.
If you move this to the Sport Touring thread you may get more replies. Most of the guys there have dealt with similar issues and are willing to respond...also check the hall of wisdom and tech threads...tons of info.
 

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I think you may have misunderstood what I was saying. I was just commenting that since you gave flynnmon's post a Like, and he mentioned moving this thread to the ST section, that I would do that for you. That's all.
ohh i was hoping you had another solution i could try and fix it. but okay buddy , understood.
 

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My st2 charges at 14.5 v which is correct, a bit lower at idle but comes up pretty quickly.

Your voltage of 13.5 shows some charging is occurring.

12.8 is full battery Voltage (no load or charging)
12.2 is dead flat

Recharge your battery out of bike, it won't have died yet.

Check the 2 plugs that connect to the regulator, pull them apart and replug them.

When its fully charged put back in bike, get it started and measure charging voltage again at 4-5k rpm.

Advise.

Noel
 

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My ST4S has always been a bit of a reluctant starter since I got it. My lad is taking over the bike and may not be as meticulous about keeping the battery charged as me. Thus, I was determined to improve things and the first thing I tried was uprated battery leads (I got a kit off ebay). The old leads "looked" ok with no visible corrosion at the terminals The bike is not being used regularly on the road yet but its definitely turning over faster and catching much sooner. I'm now not going to bother checking the starter or solenoid. It seems that everything seems to need to be pretty much spot on for a quick start on these bikes.

Keith
 

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It could actually be the RR. My 2003 ST4s charges "ok" at 13.6V, but my ST2 charged at 14.4V (both above idle). I had a 'Guzzi that charged at 12.5V. The AGM battery in that bike needed more. I put in a used Ducati RR (a 3 wire RR, and that system was just 2 wire), and that cured it. But this was after checking the entire AC side of the stator (including loading the AC output!), and loading the output of the RR.

I know the connections on my current ST4s are fine, because they do not get warm at all. My next step for my "ok" system is to swap out the RR and see if that makes better voltage. I say "ok", because the battery doesn't seem to mind after a days worth of riding, but my heated gear is much hotter at 14 V than at 13.6V. Do the math, the power delivered is Esquared / R, where R is constant (like 2 ohms for my jacket).

No wonder my ST2 used to "feel" better over an idle on a cold day... 14.5 V ooohhhh yah, feel the burn...
 

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Hi everyone, please help me before i burn this bike Ducati ST4S

I bought a new battery for it because the old one died. battery is fully charged, but still suffers to turn over. when i jump start it with my car it starts and all but then when i switch it off and try starting it with its battery it some times starts but even then its like by chance.

Battery is brand new and correct type as manual. but still having a hard time to turn over. any help will be much appreciated.
Hi everyone, please help me before i burn this bike Ducati ST4S

I bought a new battery for it because the old one died. battery is fully charged, but still suffers to turn over. when i jump start it with my car it starts and all but then when i switch it off and try starting it with its battery it some times starts but even then its like by chance.

Battery is brand new and correct type as manual. but still having a hard time to turn over. any help will be much appreciated.
Has this bike had any modifications done? Clean the heck out of all the battery leads. What helped my 1999 ST4 was upgraded heavier duty battery leads..home built, a new Shorai battery and removal of the plug going to the voltage regulator, the 3 wire plug nearest the voltage regulator under the right side upper fairing. That plug has been a source of problems right from the factory....overheated wires. Don't ask me how I know, but if you ever smell hot plastic melting.....look there first. I just soldered my 3 wires together and eliminated the male/female plug. All good for the last 12 years. Bike fires right up. Shorai battery going strong after 6+ years. Maybe this will help?
 

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Agree. Run the bike, maybe 2000rpm, turn on high beam, light the brake light, turn on any heated gear. Then feel the connectors that feed the RR, and the output connector. If they are warm or hot, get rid of the connector. I did on my ST4s, and my wires are cool now.
 
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