2025 KTM TBI Starting issues

BH_84
Posts
370
Joined
10/28/2024
Location
Cameron, ON CA
Fantasy
Edited Date/Time 5/10/2025 7:45am

Haven't seen this specific issue mentioned anywhere, but its happened with 3 bikes in a row here at the shop. 2025 125SX, 150SX and 300XC-W. All 3 have had issues with no wanting to start. 

The 125SX we were able to get going by plugging it in and manually cycling the fuel pump. 

The 150SX was fouling plugs, turned out the customer was using some cheap Castrol oil to mix. We replaced 2 sensors and  replaced the fuel with new gas mixed with Motorex 2T. Doesn't seem to have the issue anymore but it only went back out yesterday.  

The 300XC-W didn't have the option to cycle the fuel ump when hooked up to the computer. We had to spray ether through the intake to get it to go. After that it seems to start fine. 

 

Anyone else having issues like this? It seems to me that there should be a way to prime the fuel pump. On ATVs and motorcycles with keys and on/off switches it primes as soon as you flick the switch on before you push the start button. 

|
Factor E
Posts
962
Joined
9/22/2011
Location
So Cal, CA US
5/12/2025 2:27am

Sounds like injectors not holding pressure/Dirty   Internal leak fuel pump/look for bubbles in tank while running    

BH_84
Posts
370
Joined
10/28/2024
Location
Cameron, ON CA
Fantasy
5/12/2025 8:21am
Factor E wrote:

Sounds like injectors not holding pressure/Dirty   Internal leak fuel pump/look for bubbles in tank while running    

These bikes are brand new out of the crate. But stanger things have happened. Might be worth a shot if one comes back again. 

Factor E
Posts
962
Joined
9/22/2011
Location
So Cal, CA US
5/12/2025 6:15pm

You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are you using?       Have dealt w small plastic fragments from production clogging pumps  

BH_84
Posts
370
Joined
10/28/2024
Location
Cameron, ON CA
Fantasy
5/13/2025 8:00am
Factor E wrote:
You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are...

You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are you using?       Have dealt w small plastic fragments from production clogging pumps  

We're the dealer. Flashing the ECU isn't the one touch fix you think it is. 94 octane fuel mixed 40:1 with Motorex 2T as per KTM's spec. 

The next one it happens to is definitely getting the injectors pulled and put through the cleaning machine. 

The Shop

11/29/2025 5:38pm
Factor E wrote:
You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are...

You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are you using?       Have dealt w small plastic fragments from production clogging pumps  

BH_84 wrote:
We're the dealer. Flashing the ECU isn't the one touch fix you think it is. 94 octane fuel mixed 40:1 with Motorex 2T as per KTM's...

We're the dealer. Flashing the ECU isn't the one touch fix you think it is. 94 octane fuel mixed 40:1 with Motorex 2T as per KTM's spec. 

The next one it happens to is definitely getting the injectors pulled and put through the cleaning machine. 

You ever find the cure to this?

Buddy has a 25 125sx that he says fouls plugs every day he rides. Its his kids bike so it may not be getting wrung out enough either

BH_84
Posts
370
Joined
10/28/2024
Location
Cameron, ON CA
Fantasy
11/29/2025 6:02pm
Factor E wrote:
You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are...

You still have a warranty on them    Dealer can re Flash ECUs   The common you have w them is fuel      What are you using?       Have dealt w small plastic fragments from production clogging pumps  

BH_84 wrote:
We're the dealer. Flashing the ECU isn't the one touch fix you think it is. 94 octane fuel mixed 40:1 with Motorex 2T as per KTM's...

We're the dealer. Flashing the ECU isn't the one touch fix you think it is. 94 octane fuel mixed 40:1 with Motorex 2T as per KTM's spec. 

The next one it happens to is definitely getting the injectors pulled and put through the cleaning machine. 

BirtDikes wrote:
You ever find the cure to this?Buddy has a 25 125sx that he says fouls plugs every day he rides. Its his kids bike so it...

You ever find the cure to this?

Buddy has a 25 125sx that he says fouls plugs every day he rides. Its his kids bike so it may not be getting wrung out enough either

ECU reflash, and when it doesn’t want to start, wait for the green light on the bars to go out, then hit the button again. 

Post a reply to: 2025 KTM TBI Starting issues

The Latest