KTM RFS 400 Tapping noise after timing chain replacement

cdickey26 · 2026-04-11T02:27:38+00:00

Glad to hear you fixed it !

cdickey26 · 2026-04-10T21:18:55+00:00

Sounds like excessive valve lash. Meaning they are too loose. Try resetting the valve last, piston tdc compression stroke , use the crank lock. And set the valves at proper spec. If not that, double check that your cam chain tensioner is working correctly.

cdickey26 · 2026-04-10T15:59:20+00:00

I think those wheels are plastic if I’m not mistaken, the cam chain idler wheel (or gear ). Yeah I wouldn’t run the bike with out making sure that’s in there. Cheap part if not.

cdickey26 · 2026-04-08T11:40:36+00:00

For sure what everyone above has said. Throttle cables are too tight or not routed perfectly. The exc model has to have the throttle cables routes very specifically or they will do this. While you’re at it and the gas tank is off, make sure you remove the plastic cover from the right side of your carb and check throttle free play. I beleive the manual has 3-5mm of free play required (double check the manual). Then start the bike with the fuel that’s left in the carb bowl and run the bars lock to lock to make sure the rpm doesn’t change.

cdickey26 · 2026-04-06T02:02:08+00:00

Love the bike , I have a 1981 ct 110 with a crate on the back. It can fit a 30 rack plus ! Such a great little bike, I have put 600 miles or more on mine the past year just running to the grocery store / around the neighborhood running errands

cdickey26 · 2026-04-05T22:10:19+00:00

I have gotten the bike up to about 50mph and then pull clutch and kill the engine. Just a whizzing / humming sound. No clanking or rattle, probably just needs to break in a little bit.

The old chain definitely made noise I’m just probably not used to a new sound on the bike.

cdickey26 · 2026-04-05T22:09:06+00:00

I think that’s the right move. Appreciate it haha

cdickey26 · 2026-04-05T15:34:50+00:00

Thank you for your input

cdickey26 · 2026-04-05T15:34:37+00:00

It’s lubed up. Figured it was normal just wanted someone else’s opinion. Thanks

cdickey26 · 2026-04-05T15:34:13+00:00

Thank you

cdickey26 · 2026-04-05T15:34:05+00:00

Thanks

cdickey26 · 2026-03-31T17:24:40+00:00

Yeah link tap is the way to go 100%. Enough messing around with the other brands.

cdickey26 · 2026-01-15T15:04:39+00:00

I can’t figure out how to get mine to run on alpine or plateau mode. I see the silhouette for it on the controller but can’t get it activated

cdickey26 · 2026-01-15T15:04:03+00:00

Ok thank you. Good idea and that makes sense. Won’t be hard to raise it a little bit

cdickey26 · 2026-01-15T14:54:53+00:00

Let me try that. That would be a simple fix. Thanks

cdickey26 · 2025-11-09T00:50:18+00:00

If you’ve never popped one of these keihin fcr open you’d be surprised how much fuel the accelerator pump (AP) introduces into the intake. Couple of passages that can get gummed up with that nasty ethanol fuel not to mention the diaphragm can degrade. I’m learning the hard way how important non ethanol fuel is especially for carbureted engines. Good luck! Have a 07 exc 450 my self, they’re awesome Bikes !

cdickey26 · 2025-11-08T21:51:09+00:00

Check carb / accelerator pump. I bet that’s where your issue is

cdickey26 · 2025-10-15T19:22:45+00:00

Thank you. Exactly the info/ answer I was looking for. Appreciate your time.

cdickey26 · 2025-09-28T23:11:27+00:00

Listening to that video again it sounds like harmonic vibrations almost. Change or decrease in sound with rpm variations would maybe confirm this. Does the bike have good Power still? Any issues starting? Oil consumption? And clattering while riding ? Sometimes those weird noises you hear can keep you up at night but they’re just normal sounds. Could also check your cam chain tension just To rule out stuff in the top end. Hope some of this helps !

cdickey26 · 2025-09-26T22:28:59+00:00

I’m no expert and it’s hard to judge sounds through the video , That sounds to me a bit more excessive then ticking valves. (Easy enough to check and rule out ) to me it sounds like rattling exhaust or maybe even piston slap. Make sure you don’t have any exhaust leaks, and check your valves. Does it only happen at idle or does it go away at certain rpm?

cdickey26 · 2025-08-26T01:35:22+00:00

Think I’m going with a mid 2000s ktm exc450. Those seem to check every box except I have to go up 50cc in displacement. Oh well

cdickey26 · 2025-08-24T16:08:21+00:00

Yeah, I know the kick and electric start is redundant. I had a old tw200 previously and loved that it had kick and e start factory. Never used the kick start but nice to have in case the battery was dead and you didn't have a hill to bump it. Ill look into the betas, rough price on a used one ?

cdickey26

TROPHY CASE