SuperMoto Junkie banner

1 - 20 of 28 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter · #1 ·
So last night I was riding my bike home (3am) and it just died. It cranks but won't start. It has gas. Has oil. Everything looks fine. WTF?? I mean before it stalled occasionally for no appearent reason, but would always start right back up! This time she's not for the life of me. Checked plug, looks white but don't think it's the problem? I have no clue where to start or what to do right now.. =[ any ideas? I just put a new tire on two days ago, I live in so cal and I NEED to be on my bike like right now. HELP??:headscrat
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #2 ·
Little more info... About 3k miles on her, garaged, never ridden in rain, idk what else..
 

·
Registered
Joined
·
696 Posts
Funny, I was just going to post up that my 08 is acting up. I never had the stalling problem, but it has been happening lately. Occasionally it's hard to start, other times it fires right back up.

It also runs pretty inconsistently at low rpms in 1st and second. Argh.
 

·
Premium Member
Joined
·
6,598 Posts
start with the simple stuff.

check the battery voltage to make sure it has enough power to actually get the bike started. just because it cranks doesn't necessarily mean it's enough to start the bike.

check if the fuelpump is priming after you switch on the ignition. no priming means no fuel delivery.

if you can reach the plug, check if you're getting a good spark when cranking the motor.

etc, etc...
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #6 ·
What's the most efficient way to check the fuel delivery? I'm new at EFI.. If it was a carb It would be cake=\.. I'll run thru those again tomorrow and let you guys know if I came to any conclusion.. Thanks for the advise!:thumbup:
 

·
Registered
Joined
·
689 Posts
Do you hear the fuel pump working when you startup?
Did you try to give it some gas? (you are not supposed to normally, but it will help if there is a problem)
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #8 ·
Yea Im pretty sure I herd the fuel pump when I turned on the ignition, I'm gonna have a buddy help me tomorrow so I can try and hear it better to be sure, since my instrument cluster is kinda loud... And yea I tried starting it with the throttle in a few different positions but it didn't make a difference :headscrat
 

·
Registered
Joined
·
191 Posts
My 2010 SMC was running really badly at low-revs and developed the dreaded stalling issue. I took it into my local KTM dealer and it turned out to be the TPS. It wasn't in correct alignment and was causing the FI to misbehave. Worth having a look.
 

·
Registered
Joined
·
316 Posts
does it still stroke then? compression? rings?
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #11 ·
My 2010 SMC was running really badly at low-revs and developed the dreaded stalling issue. I took it into my local KTM dealer and it turned out to be the TPS. It wasn't in correct alignment and was causing the FI to misbehave. Worth having a look.
Never got to the point where it wouldn't start anymore thought did it..? And is theyre actualy any adjustment on the TPS itself, or was it corrected electronically?
 

·
Registered
Joined
·
191 Posts
Never got to the point where it wouldn't start anymore thought did it..? And is theyre actualy any adjustment on the TPS itself, or was it corrected electronically?
It wasn't far off....the day before I took it in to the garage it wasn't far off not turning over. On the button it would turn once and the decomp would click and that was it a few times. It was a combo of the TPS (physically out of alignment) this was making it have issues with making the idle drop dramatically (sub 500rpm!) and then it would cut out. Hope that helps a bit fella
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #14 ·
Thanks for the adVise crispy, I'll look into that right now...:thumbup:

So spent the better part of my morning(12-2) workin on her, came to the solid conclusion that it is a fuel delivery problem. Checked compression. Fully charged battery. Have spark. Sprayed some fuel in the chamber threw in the plug and it fired up instantly then died... Now to figure out which part of the fuel delivery system is the corporate:hmmm:
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #15 ·
Don't want to sound like an idiot, but there is like 6+ sensors on the throttle body.. Which one is the throttle position sensor..? I tried a search but couldn't find any info.. Anyone have a diagram of the throttle body readly avail..?
 

·
Registered
Joined
·
689 Posts
Since you suspect a fuel delivery issue, do you think you can check that? See if the injector primes the cylinder to start? It could be both ways. The injector for some reason could jet less fuel, or it could be leaking and slowly sip fuel in the cylinder, making it very hard to start.

For a start I suggest you clean the injector, its not costly, and it rules one factor out. Its a shower type injector and being only one, it can have a big impact (unlike for a car for example, where it has 4+ injectors and a small problem with 1 injector is not immidieatly apparent)

Make sure you take it to someone familiar with moto injectors, and that he tests it BEFORE cleaning and after and that he checks for leaks etc
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #17 ·
So went thru the fuel system, fuel pump was pumping, fuel was in the line to the injectors, tested the injector discharge and had power, pulled the injector and it was almost completely clogged. Cleaned. Reassembled. Happiest kid on the playground right now. Thank you everyone for the advise! :thumbup:: ::bannana:
 

·
Registered
Joined
·
3,918 Posts
If the injector was almost completely clogged, you need to change the fuel filter too. If you don't, it will happen again.
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #20 ·
Where/how do you get to the fuel filter on these? :headscratIs it a pain to change or does it just look like a pain..? I'm assuming it's right at the bottom of the tank where the fuel line comes out..?:hmmm:

I cleaned it by removing the quick disconnect, then removing the injector from the TB then disassembled the injector and sprayed it out with throttlebody cleaner and reassembled.. Idk of that's "proper procedure" but it worked for me:thumbup:.. And like I said that was after testing for fuel pressure and electronic discharge etc etc ..
 
1 - 20 of 28 Posts
Top