Jump to content

'15 KTM 350 EXC will not Start

Recommended Posts

Just returned from a long trip, without my 350, and she will not start.  Lots of help on the internut on this subject.

Here's what I found and done.

Drained all old fuel, added new fuel.

Motor cranks, but will not fire.

Replaced fuel screen.

Fuel pump activiates when key turned on.

Fuses #1 and #2  check good.

Removed injector and attempted to backflush with carb cleaner and compressed air.  No luck getting anything through the injector.  Some Youtubers suggest applying 12v power to the injector pins.  Did this but nothing happened, no clicking (some Youtubers suggest it should be clicking but I seem to think the ECU regulates the pulse to the injector solenoid), no nothing, no flush or back flush.  Injector has continuity and 10.6 ohms of resistance.  I believe 10.5 ohms is normal spec.  So the solenoid is good, electrically.

Tried soaking the injector in carb cleaner overnight;  no help.

Spark plug has good spark, but, don't know if on the low voltage side.  Bike should still start, just run rough with low spark voltage.

I'm thinking the solenoid or plunger is gummed up and not moving.  I'm thinking this is the case because after working on it and attempting to start, and then letting bike sit overnight, when I remove the quick disconnect from the inline filter housing, high psi fuel goes everywhere.  This would seem to indicate I'm not getting any fuel through the injector solenoid/plunger and high psi fuel in the line is not being relieved by the injector though ECU command at shutdown.

Any thoughts or anyone have a similar experience?

Thanks for any help!

Bill

Share this post


Link to post
Share on other sites

Just watched Jeff Slaven's video cleaning a KTM injector with the Motion Pro cleaner and a 9V battery.  

I then hooked up my injector to the plug from the ECU and attempted back flushing using the bike.  Nothing.  Injector not clicking.  I'm leaning towards a failed injector.  It might still be gummed up and not clicking as a result.

Found this place.  http://www.proflowtech.com/   Might be worth $31 to have the injector tested/cleaned before dropping ~$130 on a new one.

Share this post


Link to post
Share on other sites
16 minutes ago, RollieW said:

Curious, how many hours were on the removed inline fuel screen?

I run  those things 100 or 150 hours at a time

Share this post


Link to post
Share on other sites

32 hours on the old screen.  Now have a new ZipTy filter.  It came with a new screw.  Same issue as with the OEM inline filter/screen.

Getting fuel past the inline fuel filter/screen.  No doubt about that.  

Share this post


Link to post
Share on other sites

I just reticently had a similar problem with my 500 EXC.  I was riding some slow 1 & second gear single track in the NV desert for about two hours when we stopped to gather everyone up.  When I tried to restart the bike it didn't want to start.  Tried everything we could on the trail side, and eventually got it to catch.  I made my way to the highway and back to the truck at about 1/2 power.

The dealership hooked up a gauge inline between the tank and throttle body and found the fuel pump was bad.  I was surprised because when I took the fuel line off and turned the pump on it seemed to pump with the force I would expect.  But when the pump turned off, it was not holding pressure.  Apparently the pump should hold something like 3 bar (I don't recall exactly) when it turns off.

No idea if this is your problem, but it may be worth checking.

  • Like 1

Share this post


Link to post
Share on other sites

Thx Memnok...

Definitely holding 3 bar of psi.  First time I released the QD at the inline filter, I was sprayed with gas.  Now I wrap a paper towel around the QD before releasing.  Why I think the injector is gummed up.  I'm thinking the ECU commands the fuel pump to hold psi until a command is sent to the injector to release it.  I have high psi fuel trapped in the line the next morning after attempting a start the previous night.  I don't think that should be the case.

Thx for the suggestions and help!

Share this post


Link to post
Share on other sites
On 6/17/2017 at 2:36 PM, Crazy when Offroad said:

Thx Memnok...

Definitely holding 3 bar of psi.  First time I released the QD at the inline filter, I was sprayed with gas.  Now I wrap a paper towel around the QD before releasing.  Why I think the injector is gummed up.  I'm thinking the ECU commands the fuel pump to hold psi until a command is sent to the injector to release it.  I have high psi fuel trapped in the line the next morning after attempting a start the previous night.  I don't think that should be the case.

Thx for the suggestions and help!

I have a similar issue. Did you find out what caused the issue? Dead injector or faulty fuel pump?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×