KTM EXC Electrical Issue & Fix

Often starter motor and battery charging issues can be caused by battery terminal corrosion issues. This video shows how to fix the problem and help prevent similar issues in the future.

[@mattiasmyrman]

THAAAAAAAAAANK YOU!!! Fixed my super-dead bike. Very grateful! Ground in the chassi end was the bad guy!

[@carcaridon]

I have a 2010 450 excr. It is road registered and I ride it daily usually. I rides sweet (despite knobbies and a 14/50 sprocket set up 6 SPD etc) Since I've had it,the only times it restarts with starter only is if I stall it in traffic and hit it straight away,otherwise I use it to assist in kick starting.(reqd to spin engine/alt fast enough to start) I've changed battery and starter motor and still no kick less starting. My question is could perhaps the CDI be tired or used up and be a cause of such heracy? Any help is appreciated 👍

[@matp1102]

Another good tip for cleaning the corrosion off is to just boil the kettle and pour boiling hot water over it all... More applicable on cars as they have bigger batteries and terminals so generally a lot more corrosion but it works well none the less. Used to have a 12v kettle in my work ute as I was fitting a lot of batteries on site so did this a lot.

[@kevinboe7155]

Even though my bike has a lot of erosion it still try’s to start but drives my battery dead so this could be the problem even though it’s trying ?

[@Britishguyinhouston]

I have a 2019 Ktm 250sxf that seems to be draining the battery rapidly, I have a vortex ECU on but if I put the stock ECU on it starts, it doesn’t really start with the vortex on or it’s difficult. But if I put my vortex on my mates bike it starts no problem. This is really confusing me now ☹️

[@jerkey]

What else can lead to a weak charging system? Which wires specifically? Anything coming from the stator?

[@jeremys4705]

Love your channel. Related (possibly) charge question, I sold my 2017 TX and now have a 2020 TPI TX and I love it, only 35 hours. It's super winter here and I was trying to charge Lithium battery with a lithium specific charger. The fuel or oil pump was kicking on when on charger. I tried some cleaning up terminals and diode grease as in your video and put it back on, seems to of stopped the pumps kicking on. Could this also be grounding? Have you or anyone else seen TPI bike fuel pump engage when trying to charge? I am new to TPI.

[@mbrick]

I've read that certain chargers used on a TPI will kick on the fuel pump. You'll either have to disconnect the battery to charge or try another charger. I am not aware of anyone that has figured out exactly why this happens yet.

[@midlan6]

I changed the all the bolts, nuts and washers holding battery cables to stainless steel ones and they work great!

[@herbjackson1442]

I would also run a jumper ground cable from the sub aluminum frame to the steel frame.

[@quikcolin]

Great tip! I've never had a problem, but why not take some preventative measures? I'll toss some silicone grease on them tonight. Thanks for the tip!

[@ArchieLeeming]

Hi, I have a KTM 300 '17 and find after a while riding slow/technical stuff my fan drains the battery during the ride, then i have to resort to the kickstart. Is there a better a battery i could run to give me a longer charge? like the lithium ones? thanks!

[@TokyoOffroad]

One of my friends had similar issues. We changed his stator and battery for uprated ones in this video: kzbin.info/www/bejne/aV67k5emhb1jgbs

[@serhii_khachko]

I had an issue with connection between negative wire and frame (black corrosion on aluminum) because of bad screwing. Not sure if it's common issue as well, but the point is that it needs a thread lock I think.

[@motoloko9916]

I have a ktm 350 xc-w ...so i was riding it around then it had an oil leak so pushed it home....now .it has compression but wont start what should i do?

[@pcmandan]

had this issue my self, it also created issues on the tpi where it could cut out on the road not rev hard & bring on the EML light

[@crazybalony]

Love you videos, so well done! Quickly, I have a clicking sound when I press the starter button. I took a screwdriver and shorted the two terminals on the starter selenoid. That in turn had the starter turn over. So I know the starter isn't the issue. Could that be indicative of a faulty starter selenoid?

[@TokyoOffroad]

Pleased to hear that you enjoy the videos. Yes, from your description it sounds like the starter solenoid is faulty, or the solenoid terminals are corroded and causing the problem. Try cleaning the connections and if it still doesn’t work replace the solenoid…

[@travisk5589]

the silicon/dieletric grease keeps air out of the connection. THe o2 forms oxides on the aluminium which in turn lessons the connection. I soldered my neg cable to the frame and havent had a connection problem since.

[@robertcox811]

So after spending £25 on a new starter relay, this was actually the fault!!! I couldn't understand how the battery voltage was good up until the terminal of the relay then losing it as soon as I tried to load the relay. I actually considered it to be something far more complicated. And, it was the connection to the frame and not the battery terminal!!! Massive thank you. as basic as it is, I would never have thought it to be that. I owe you a beer!!!

[@KekoMusik]

Help me mi friend i jave a ktm690 r wen i run it they just off and not want to start again in 15 min i have to wait the electrical its shut dwon i clean but does not work any advise thnks!

[@kiwi-moto]

a few years late, but just wanted to point out that the washer you mention in at 7:30 should actually be mounted UNDER the cable lug and screw according to the Official KTM factory repair manual. Not sure why, but they definitely make a point of that and the orientation of the claws.

[@TokyoOffroad]

I just checked the repair manual and you're correct, the washer is shown between the battery terminal and the cable lug. Interesting! However, not very easy to assemble like this though and quite likely to lose the washer when taking apart. Personally I think that so long as the parts are kept clean and free of corrosion there shouldn't be a problem either way. Highly recommend using some dielectric, or silicone grease to help prevent corrosion (particularly the negative battery to frame connection).

[@mesbahe]

Do you do any other kind of maintenance to the lithium ion battery. ie do you trickle charge it? or remove the connections when the bike is stored for a few days? Or is it maintenance free?

[@TokyoOffroad]

If you ride regularly (at least once a month) then a lithium battery should be maintenance free. However, if you're not going to be riding the bike for an extended period of time (E.g. if you don't ride in the winter), it would be a good idea to disconnect the battery, or use a lithium battery safe tender. Lithium batteries do not like to be fully discharged and will often not recover after they have been. You should therefore be careful that the parasitic current load on the battery when the bike is very low (can be measured using a multimeter set to current measurement mode and connect the meter in series with either of the battery terminals). E.g. if you hook up an unswitched accessory to the battery and leave it powered on while the bike is not running, if the battery fully discharges it will likely kill it and not recover, even if you try to charge it.

[@mesbahe]

@@TokyoOffroad Thank you for the helpful information. You are a life saver.

[@sterlinglapratt2855]

YOU ARE THE MAN!

[@jeffinhoodriver]

Would there be a problem with using a rubberize it type of product to cover the connecton to prevent corroson?

[@TokyoOffroad]

I wouldn't recommend that. A small amount of grease works fine and allows for easy connection, dis-connection.

[@jeffinhoodriver]

@@TokyoOffroad ok cool thanks for the response

[@Coal-Creek-Rider]

A big thank you for this video I followed your video and Bam my bike runs again!!!!

[@TokyoOffroad]

Pleased to hear that you found the video useful

[@brycechow9178]

i have a 2016 sxf 250, the top end was just rebuilt 18 hours ago and now i am having issues with my bike shutting off after it warms up(about 30 minutes of riding) the bike will bogg down and die after that happens my electric start completely fails. i have checked all the connections and the ground wire. any thoughts?

[@gynn4622]

Ever figure it out?

[@brycechow9178]

@@gynn4622 yes, it was the electric start switch wire behind of the front number plate. it had a little connecter that it plugged into but the wire was corroded and had a bad connection, i just cut the plastic connectors off and wired it straight together and covered with electrical tape the bike has been working fine ever since then.

[@hodes58]

Very well done. Thank you for the thorough video.

[@Asaphunnna]

Is it a big deal I don't have that washer that goes under the bolt, the one your talking about in the video? will that cause any damage. Just took my battery apart and realized I dont have those washers

[@TokyoOffroad]

If the terminal is clean and screw stays tight I wouldn't worry about it. But if you find the screw comes loose after a while then having the washers would certainly help prevent this.

[@Asaphunnna]

Tokyo Offroad I really appreciate your advice

[@charlvanniekerk8881]

Thanks. I disliked the video at first. 10 min video only about something as simple as ground. But then it was the problem I had with my bike. 😁😅💪🏻 Now I like it

[@TokyoOffroad]

Charl van Niekerk - Yes, it’s good idea to clean and grease the battery connections and frame ground connection periodically to avoid any issues

[@kaybragard]

Hi, I checked all your video's, but can 't find my problem i have. Maybe you can help me? I have a 2021 husqvarna te300i : fuse 1 :10A Always melts. It has been 2 months i didn't ride. Last thing i did, was install an OEM fan. Today i rode 5kms and all of a sudden the 10a fuse melted. After that i put a New one. It didn't melt When starting, but one I rode it, it dies.. Maybe you can help me? Kind regards

[@Globalbeast_]

I have the same on my KTM sxf 450 don’t wanna take it to the dealer yet

[@michellegabriel8996]

A possible solution/remedy is to fit a rubber boot to the negative connection same as the positive....to exclude water/moisture ingress.

[@carlosdasilva5112]

Hi there, I have a 2017 ktm 300 xcw here is South Africa and yesterday washed the bike just the engine and wanted to start it up to warm her up, hit the e botton and only to hear a click? Any idea what that might be? Very good information on your videos, just did my top end watching your channel. Looking forward to hearing from you.

[@TokyoOffroad]

Carlos Da Silva - I recommend first checking that the battery connections are clean and tight. Also check the battery earth cable frame connection as this can easily become corroded. Next check the battery is fully charged and then try starting. If it still doesn’t start then the proble is probably with the starter motor (either electrical connection issue, the starter is jammed, or the starter motor is broken. But the most likely cause is the battery connections, game ground, or battery is fully charged.

[@RomanovichAutoSurgeon]

Hey guys I got a 2007 Ktm 450 Sxf and I’m having problems getting it to do much when I hit the button to start. I have already changed the starter, stator, flywheel -from trail tech, and very strong battery. I used to get the starter to turn over once or twice but now it’s not wanting to do that. Need serious help

[@TokyoOffroad]

When you press the starter button does anything happen? You should be able to hear the starter solenoid click when you press the starter button. The solenoid terminals should be easy to probe with the voltmeter. One terminal is connected to the battery, the other to the starter motor. When you press the starter button what voltage do you see on the terminal connected to the starter motor? If you don't hear a click when you press the starter button the starter switch may be the issue. Or you may have a ground issue (check the battery connections and frame ground connection, clean if corroded). Is your battery fully charged? If you see high enough voltage on the solenoid output and the starter isn't turning the starter motor may need replacing. If you remove the starter motor you can test it by connecting it directly to a battery and see if it turns.

[@RomanovichAutoSurgeon]

starter motor is brand new, yes it turns over. The starter Solenoid used to click, now its just a quiet click. I tested the resistance of the solenoid and it checks out, .2 ohms and 4.7 ohms on the other two. Ground is not corroded and been cleaned several times. Got a brand new lithuim battery and for some reason its only wanting to show 9.22v DC. When it was able to go to 13.5, thats when the solenoid click properly. But even when the solenoid clicked porperly, all I would get is the starter to turn over like once or twice and give up.

[@TokyoOffroad]

9.22V battery voltage is far too low. Have you tried charging the battery. As it's a lithium be careful about what charger you use. A smart charger intended for a lead acid battery will kill a lithium battery if run it the desulpher mode.

[@RomanovichAutoSurgeon]

yes when I got it first it was charged 100% 13.22 and I got a specific charger with it from a motorcycle store.

[@r.cic1596]

D-Rock_ TM was it the regulator? Sometimes the plug gets water and gunk jammed in there not allowing proper flow that’s where I’m at now

[@WlPPAN]

I had huge problems with my Ground connector cable. It shortened the hole thing. The startmotor just went *clicking*. What I did was running electrical tape around the ground cable to the subframe and then it worked...

[@nathanpenny52]

Did you wrap the tape around the wire ?

[@Globalbeast_]

Mine blows the fuse on the starting relay I bypass it and don’t start either some opinions?

[@TokyoOffroad]

What exactly did you bypass, the solenoid output terminals, or the fuse? If the fuse at the solenoid is blowing it indicates that the electrical current load on the fuse is too high and you'll need to debug what's causing that. It might be a cable with worn insulation shorting to ground, or a component has gone bad. For the starter system to operate correctly the fuse needs to be good or the solenoid will not be able to switch on.

[@hardendurobosnia17]

Can you put electrical contact spray on it?

[@TokyoOffroad]

IMO the best thing to do is use a wire brush the connections, apply some silicone grease and re-assemble. This should help ensure a good electrical connection.

[@mas4133]

Starter motors require a bit of current; I found any impedance in the + or - feeds will be a deterent at the wrong time. After replacing battery & rebuilding the starter motor on my 2001 400 EXC, found that I should have utilized a redundant ground lead directly from battery (-) terminal to starter motor case mounting. Relying only on the negative circuit connections between battery through subframe, main frame, motor mounting, etc are points for electrical conductivity problems. Another item is to replace battery terminal bolts with a stud and nut over each cable as later best to replace the stud rather deal with worn battery female threads.

[@hugomx5387]

2014 300 Exc. Hopefully someone can help me but I can't find the problem. My KTM was fully working when I bought it but haven't started it in 4 months but now all electronics aren't working, when I put a new battery in the bike it can start with the button but the rest of the electronics still aren't working. No display no horn no lights, and the battery di*s after a few hours maybe a day. Bike Always starts with the Kickstart. Please help.

[@hugomx5387]

Yes I have cleaned and checked all connections

[@luuk4509]

I did this didn't work checked al my cabbles. Is IT possible that my start relais is broken ?

[@TokyoOffroad]

Does your starter solenoid make a click noise when you press the starter button? If it doesn't check the starter switch, starter switch wiring and the solenoid. A multimeter makes this type of debug quick and easy.

[@steveg4261]

Exacly same problem I did check all connection and I have a click nose. Bike starting some time after 5 pressures on the start button and sometimes directly... is it a problem from the start relay or can be from brush starter ?

[@katrinacorcoran]

@@steveg4261 I have the exact same issue. Intermittent failure to start. Battery is new and starter clicks. Did you discover what your issue was?

[@steveg4261]

@@katrinacorcoran try to change the starter relay. 🤙

[@katrinacorcoran]

@@steveg4261 I will keep that in mind. I finally got to test the battery today and clean the contacts. I found a loose connection when I was doing this which was certainly part of the problem.

[@JoseGonzalas]

I once accidentally dropped my 13mm combo wrench after I installed 2 truck batteries in series into a rock truck. Unfortunately it fell right across the leads of one of the batteries. Smoked that wrench😞 quite literally actually

[@mart242]

why apply dielectric grease on the terminals? dielectric grease is an insulator.. won't it make things worse?

[@TokyoOffroad]

Yes, the grease is an insulator, but it gets squeezed out and only fills the gaps. It stops water getting in and thus helps prevent corrosion.

[@mart242]

Hmm. surprising. I thought that some would remain in there. I guess it must work of you do that however.

[@TokyoOffroad]

Yes, it's a commonly used method to reduce the risk of corrosion on battery and connector terminals.

[@shimagaijin1]

Some 4-strokers need a capacitor mod to “bump start”.

[@TokyoOffroad]

Yes, I've sold some BLS Capacitors to 4-stroke customer too (mostly 500s) and it works fine on all the bikes tested so far.

[@mijosipek5052]

Is the ground conection galvanic corosion or just normal ocsidation?

[@mijosipek5052]

After watching the whole video it seems its galvanic, on the ground should be a diferent material for connection, dont know which one from the top of the head...

[@TokyoOffroad]

Yes, creating electrical contacts between different metals will often result in issues. For galvanic corrosion to occur an electrolyte is required (E.g. water). For this reason the use of grease, to prevent water getting to the contact area, will greatly reduce the galvanic corrosion. Ether way I've decided to try running a thick 8 gauge cable directly from the battery ground to to the starter motor ground to minimize future issues. I'll make a video soon to show the modification.

[@dawn-moon]

@@TokyoOffroad so copper grease is a bad idea ? ( copper + alu ) I used it on a 690 with ground issues, never had issues ( maybe because of the weak current you can get away with it ? )

[@knighthawk3559]

If you put a screwdriver across both terminals, it will restore the plates back to nearly new condition. Takes about 5 minutes 👍

[@massimobroccoli9854]

I have only a capacitor !

[@keitherikson7147]

What do I do if the button works but doesn’t start the bike

[@TokyoOffroad]

When you press the starter button what happens. Does the starter motor spin? If the starter motor spins and the battery is in good shape and fully charged, but the engine doesn’t turn over the issue is probably the bendix. In this case replace the bendix with a new one. Does the bike start with the kick starter?

[@keitherikson7147]

Tokyo Offroad yeah it starts with one kick with the kick start but when I try to use the electric start it just keeps making the electric start noise and doesn’t turn on

[@TokyoOffroad]

@@keitherikson7147 - If the starter motor is spinning (it will make a whirring sound), but the engine does not turn over it means that either you need a new bendix, or the battery voltage is low and the starter is not spinning fast enough for the bendix to engage. The bendix internals will tend to get gummed up over time, preventing the bendix gear moving out when it spins. Cold weather will make this worse. You could try cleaning the bendix internals and re-lubing, but it's not really designed to be taken apart and serviced. It you do lube the bendix do not use any heavy lubes, or it will make it worse. A dry lube works well, but be sure to clean out the internals thoroughly before lubing.

[@keitherikson7147]

Tokyo Offroad ok thanks very much I subscribed looking forward to more vids

[@josealfonsoroblesbotia8332]

10min to clean a cable

[@TokyoOffroad]

jose alfonso robles botia - Yes, quick and easy to do. Definitely worth checking regularly

[@brodyenglish7534]

My Ktm 300 won’t even click

[@TokyoOffroad]

Check your battery (recharge, or replace if dead), ground connections, fuse, starter switch, connector by the triple clamps and wiring which leads to the starter solenoid and if all of those are OK the starter solenoid might need replacing.

[@JamesBond-py8xs]

Or just get a Honda and never have any problems with it starting

[@TokyoOffroad]

You are correct, Honda 2-strokes never have electric start issues, because they don't have electric start.

[@JamesBond-py8xs]

@@TokyoOffroad actually I meant a xr 400. I've had mine for 22 years with little maintenence or issues, then I get a 2012 KTM, have some work done on it and got it back yesterday just to end up flooding the plug today after 25 minutes on it. It did start once after kicking it, but only once. Guess I'll see what I can do with it tomorrow

[@fireflagrant]

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