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Discussion Starter · #1 ·
Hello all. I have a new to me 2013 500 EXC, 83 hours and 4100 kms, really good shape. I went for my first ride last weekend. The bike worked great for the first 15 minutes then started to act up, it wouldn't take any throttle, would just bog, had to keep the revs really low in a high gear to get out of the woods. When I got it home I pulled the plug and it was very white, it was lean to the point the metal on the spark plug had turned a blue shade. The filter in the fuel line was new but checked it and it was clean. Spark plug was new. Took the tank off and poured the fuel out and looked inside, there was no sign of any dirt, it was very clean. All connections were good. Put everything back together and added fresh fuel. My friend took it to his Husqvarna shop, they checked the fuel pressure and it was within spec. They drove the bike off and on for almost 2 days and it worked perfect. So yesterday I got my gear on and went for a ride, didn't get out of the subdivision and it stumbled a few times when giving it throttle and backfired once, then it was fine again. Drove it around for a little while and it stumbled a few more times. I am afraid to take it back into the woods because I don't trust it.

Anyone have this issue before or have any idea what the issue might be?

Thanks in advance for any guidance.
 

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Hello all. I have a new to me 2013 500 EXC, 83 hours and 4100 kms, really good shape. I went for my first ride last weekend. The bike worked great for the first 15 minutes then started to act up, it wouldn't take any throttle, would just bog, had to keep the revs really low in a high gear to get out of the woods. When I got it home I pulled the plug and it was very white, it was lean to the point the metal on the spark plug had turned a blue shade. The filter in the fuel line was new but checked it and it was clean. Spark plug was new. Took the tank off and poured the fuel out and looked inside, there was no sign of any dirt, it was very clean. All connections were good. Put everything back together and added fresh fuel. My friend took it to his Husqvarna shop, they checked the fuel pressure and it was within spec. They drove the bike off and on for almost 2 days and it worked perfect. So yesterday I got my gear on and went for a ride, didn't get out of the subdivision and it stumbled a few times when giving it throttle and backfired once, then it was fine again. Drove it around for a little while and it stumbled a few more times. I am afraid to take it back into the woods because I don't trust it.

Anyone have this issue before or have any idea what the issue might be?

Thanks in advance for any guidance.
Could be overheating.
There is water in the radiators?
Is the water pump working?
 

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Discussion Starter · #3 ·
Could be overheating.
There is water in the radiators?
Is the water pump working?
Seems to be more of a fuel delivery issue. Full of coolant. It doesn't seem to be overheating but I will check coolant circulation. Thanks.
 

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Your white spark plug would certainly indicate lean fuel mixture. Intermittent troubles are tricky to locate. You mention fuel pressure tested okay. I assume your bike is fuel injected. Perhaps rigging pressure gauge on handlebar for testing could help isolate problem. Some fuel pump failure are tricky to find because they can work good for days or hours and $hit the bed after you get halfway home. I would check fuel delivery carefully for troubles and would not hesitate to throw a fuel pump at that symptom.
 
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Discussion Starter · #5 ·
Your white spark plug would certainly indicate lean fuel mixture. Intermittent troubles are tricky to locate. You mention fuel pressure tested okay. I assume your bike is fuel injected. Perhaps rigging pressure gauge on handlebar for testing could help isolate problem. Some fuel pump failure are tricky to find because they can work good for days or hours and $hit the bed after you get halfway home. I would check fuel delivery carefully for troubles and would not hesitate to throw a fuel pump at that symptom.
Yes, it is fuel injected. I am thinking the same thing about throwing a fuel pump at it. It was suggested that I take the fuel pump out and ensure the screens are clean. All Balls has a rebuild kit that looks to be good quality and is reasonably priced. If I am going to go to the trouble of taking the old pump out for inspection I may as well replace it, would eliminate the pump for troubleshooting purposes, and if it is not a pump issue at least I will have a spare on hand for the future.

Anyone have any experience with the All Balls rebuild kits?

Thanks for the reply.
 

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Just to stay with the “simple things first” concept and not meant as an insult,
Did you use the choke or cold start when you are running it? Check that it is closed after the the bike warms up. Mine used to close automatically but then one day stopped and I experienced the same symptoms as you. It would intermittently not close itself. Now I am in the habit of closing it myself.


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I've shared my story a few times on here but will go to this again that I would guess fuel pump is on its way out.

2017-2019 all had their issues with crappy KTM / Husky fuel pumps. Mine started acting up at 65 hours where the bike wouldn't want to start. Took everything apart and couldn't find anything wrong or disconnected so then took a rubber mallet to the tank and whaddya know she fired up immediately.

Took it out on a road trip thinking would be fine just maybe a shorted wire or something and again, had issues on the trails with the bike starting and running properly.

Sold the bike immediately after I got home and new owner said they ended up replacing the fuel pump a few weeks later with an after market one for $180 rather than the $400 KTM wanted.
 

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Discussion Starter · #8 ·
Just to stay with the “simple things first” concept and not meant as an insult,
Did you use the choke or cold start when you are running it? Check that it is closed after the the bike warms up. Mine used to close automatically but then one day stopped and I experienced the same symptoms as you. It would intermittently not close itself. Now I am in the habit of closing it myself.


Sent from my iPhone using Tapatalk
Also a big believer in looking for the obvious simple stuff first. I don't use the cold start but did check it after your message, it was pushed in. Thanks for the suggestion.
 

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Discussion Starter · #9 ·
I've shared my story a few times on here but will go to this again that I would guess fuel pump is on its way out.

2017-2019 all had their issues with crappy KTM / Husky fuel pumps. Mine started acting up at 65 hours where the bike wouldn't want to start. Took everything apart and couldn't find anything wrong or disconnected so then took a rubber mallet to the tank and whaddya know she fired up immediately.

Took it out on a road trip thinking would be fine just maybe a shorted wire or something and again, had issues on the trails with the bike starting and running properly.

Sold the bike immediately after I got home and new owner said they ended up replacing the fuel pump a few weeks later with an after market one for $180 rather than the $400 KTM wanted.
I am hoping it is the fuel pump, we will see when I get the rebuild kit, fingers crossed. Don't know what to look at next. I can't imagine the injector would be sporadic....
 

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I am hoping it is the fuel pump, we will see when I get the rebuild kit, fingers crossed. Don't know what to look at next. I can't imagine the injector would be sporadic....
I'TS probably the fuel filter. Mine had a little debris in it and did what you're explaining. Take that tiny filter out and replace it. Then upgrade to a better fuel filter like an inline Golan. Best wishes.
 

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Discussion Starter · #11 ·
I'TS probably the fuel filter. Mine had a little debris in it and did what you're explaining. Take that tiny filter out and replace it. Then upgrade to a better fuel filter like an inline Golan. Best wishes.
It had a brand new filter in it prior to my ride. I did check it afterward though and it was clean. Thanks for the suggestion though!

While I'm waiting for the fuel pump rebuild kit I decided to use the down time to clean the injector, it is in the ultrasonic cleaner right now. Hope that helps as well...
 
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