2003 KTM 350EXC-R bog!

[FlangMasterJ]

Hey team I'm getting bog/hesitation off idle when opening the throttle quickly. It's fine when I roll it on slowly but anything quicker and it hesitates. The bike starts in one kick and idles beautifully. Any ideas?

This was the KTM I just had recovered after being stolen nine years ago. Apart from some scratched up plastics, general dirtiness and lack of regular maintenance it looks to be in good condition.

I've already replaced the air filter (pretty sure it was the same one I installed nine years ago), replaced the throttle cable; the push/close cable was frayed right after it exited the housing causing it to hang up when the throttle was closed this fixed the hanging RPM problem. I've also had a friend who is pretty clued up on his bike mechanics look over the carb and he said it was surprisingly clean.

So apart from this bog problem she's good.

[OllyMoto]

Hey team I'm getting bog/hesitation off idle when opening the throttle quickly. It's fine when I roll it on slowly but anything quicker and it hesitates. The bike starts in one kick and idles beautifully. Any ideas?

This was the KTM I just had recovered after being stolen nine years ago. Apart from some scratched up plastics, general dirtiness and lack of regular maintenance it looks to be in good condition.

I've already replaced the air filter (pretty sure it was the same one I installed nine years ago), replaced the throttle cable; the push/close cable was frayed right after it exited the housing causing it to hang up when the throttle was closed this fixed the hanging RPM problem. I've also had a friend who is pretty clued up on his bike mechanics look over the carb and he said it was surprisingly clean.

So apart from this bog problem she's good.

Could be a number of things but i would probably start with fueling from what you describe. Either its getting too much fuel on quick throttle openings or not enough but also low compression could give you similar symptoms, check valve clearances and if all checks out with carb setup/wear then id pull the top off and have a look at piston and rings/bore. Especially given the age of it and that its been stolen recovered, Probably had a good thrashing without much love somewhere along the lines.

[FlangMasterJ]

Could be a number of things but i would probably start with fueling from what you describe. Either its getting too much fuel on quick throttle openings or not enough but also low compression could give you similar symptoms, check valve clearances and if all checks out with carb setup/wear then id pull the top off and have a look at piston and rings/bore. Especially given the age of it and that its been stolen recovered, Probably had a good thrashing without much love somewhere along the lines.

Thanks mate. It's going into TSS tomorrow.

[FlangMasterJ]

Turns out the accelerator pump wasn't functioning correctly. Runs sweet now.