Thanks for taking the time to share your experience, knowledge and process of elimination along with the ultimate solution. It helps all of us in the community. Greatly appreciated!
This is the identical thing that happened to my 2020 KTM 300 WC-W. 25 hours on it, ran perfect. Then sat for 3 months and it would not start. The cause is, from sitting, the rings will "freeze up" for me it was the summer heat in, FL. The cure (besides a new 2024 XC300) was a new top end, then noticed the broken "frozen" ring. I also put in a new Boyson Rad Valve in. A new fuel pump for the heck of it, then remapped the computer and now have a screaming engine! And still perfect suspension. The 2024 XC 300 is better, I can't believe it, but true. I'll do a video on it on my Dirt Bike Channel. It will be easy to find.
There is a bolt on the right side of the engine that has a very thick washer. Put the engine on TDC on the compression stroke, remove the washer from the bolt and re-install the bolt slowly. There is a hole in the crankshaft that the bolt fits into and locks the crankshaft at TDC. This information is in the owner's manual.
@@slaverace1 Thanks Jeff - I'm familiar with the lockout bolt but wasn't sure it was suitable for taking the load from a leak down test. Sounds like it's fine.
I had about 4 spare fuel pumps from various KTM's. Then a tech checked a 690 issue and said it had a cracked fuel filter. I challenged him and he said he never sees bad fuel pumps. Then he tested my (4) bad ones and they were all fine - just had split fuel filters. Even when I saw where they were split the minute he shut the power off, I could not see any hint of a split or crack. He had a small test setup with a spare battery and alligator clip leads, pressure gauge and fuel supply cup. I learned the difference between a hack (me) and a real tech (him). That was 4 years ago and not a single fuel pump has been replaced by anyone in our friend group. They have always been split/cracked filters.@@WeaponsEducation
Thanks for taking the time to share your experience, knowledge and process of elimination along with the ultimate solution. It helps all of us in the community. Greatly appreciated!
You're very welcome!
I listen to this every night before bed. Thanks Jeff!
ZZZZZZZZZZZZZZ
70/90mph that’s not stupid that’s throttle therapy your words not mine lol happy new year Jeff👍
I had the exact same ring breakage on a 25 hour 350FX, no idea why. New rings and gaskets and she's now up to 100 hours with no problems.
This is the identical thing that happened to my 2020 KTM 300 WC-W. 25 hours on it, ran perfect. Then sat for 3 months and it would not start. The cause is, from sitting, the rings will "freeze up" for me it was the summer heat in, FL. The cure (besides a new 2024 XC300) was a new top end, then noticed the broken "frozen" ring. I also put in a new Boyson Rad Valve in. A new fuel pump for the heck of it, then remapped the computer and now have a screaming engine! And still perfect suspension. The 2024 XC 300 is better, I can't believe it, but true. I'll do a video on it on my Dirt Bike Channel. It will be easy to find.
Same exact thing, 21 fe501 132hours, i called the store to find out what you did with it, sold to employee that put high compression wiseco
Good info again. How did you hold the engine at tdc for the Leak down test?
There is a bolt on the right side of the engine that has a very thick washer. Put the engine on TDC on the compression stroke, remove the washer from the bolt and re-install the bolt slowly. There is a hole in the crankshaft that the bolt fits into and locks the crankshaft at TDC. This information is in the owner's manual.
@@slaverace1 Thanks Jeff - I'm familiar with the lockout bolt but wasn't sure it was suitable for taking the load from a leak down test. Sounds like it's fine.
Wow, thanks for the info.
Any time!
Great info, as usual! Curious, how many miles and hours were on it?
3000 miles.
@slaverace1 thank you! That's pretty good, since KTM rebuild schedule is like 17 hours, or something.
How many hours of use did that 4t engine have? Best regards from Guadalajara Mexico 🔥
3000 miles.
It's called stupid fun Jeff... 😆. Been there done that.
With your 24 300 do you have any pistons-cylinder problems like we can see on youtube?
Absolutely not. Had my head off yesterday for a video and it looks perfect and runs very well.
So bad pump, and broken ring at same time ?
Hope I never need to know this....but thanks!
Dumb question…..what did the low fuel pressure have to do with low compression?
Probably nothing, just the first thing he checked and there was none. Although he didn't say he checked it after the replacement pump was installed.
Always throw a new fuel pump in. period.
I had about 4 spare fuel pumps from various KTM's. Then a tech checked a 690 issue and said it had a cracked fuel filter. I challenged him and he said he never sees bad fuel pumps. Then he tested my (4) bad ones and they were all fine - just had split fuel filters. Even when I saw where they were split the minute he shut the power off, I could not see any hint of a split or crack. He had a small test setup with a spare battery and alligator clip leads, pressure gauge and fuel supply cup. I learned the difference between a hack (me) and a real tech (him). That was 4 years ago and not a single fuel pump has been replaced by anyone in our friend group. They have always been split/cracked filters.@@WeaponsEducation
Hello: I prefer to diagnose problems and replace the appropriate parts as needed, not just swap parts until I hit the jackpot. Just sayin.
Ring grove wear ???
None.
Interesting failure👍
Agreed.
Cylinder get damaged?
No