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They said general wear & tear (which is why i called precision to ask them about their maintenance intervals as well). PC did not find anything to diagnose a further issue so marked it up to general wear & tear. I asked if i sucked dirt in about 3x & they inspected the air boot & said no does not appear I sucked dirt in. I asked if maybe an oil pump was bad, they also said cannot find anything. They've been looking for a further cause but really just the rod wore a groove & then as I rode it more it made it much worse.
They said since i'm a faster rider that it wore out faster. They also said i definitely should have done a piston way sooner & that MAY have helped but they can't say for certain. Owner's manual says 15 hours do a piston lol, also says to "inspect the crankshaft" every 15 hours. I looked to see if they had a crank interval in it but i could not really find anything on their crank intervals. Precision Concepts says they go 20-25 on pistons. I am planning on doing my pistons at 35-40 hours this time around.
I find this all really strange as I race the same class and am not easy on bikes at all. Almost 100 hours on my '21 and I haven't done anything to the engine other than check valves twice, and they were in spec. I change my oil and do an air filter every ride, but sounds like you do similar. I also do put in new clutches pretty often to make sure I am getting all the power to the ground and not put unnecessary RPM's on the engine.
I ride a ton of deep sand, dry/dusty shit, and still race A class moto on occasion. I am about to pick up a '23 as a freshie, but my '21 motor and bike still feel very tight. I believe I am going to keep it as a buddy/backup bike.
I'd like to hear more from KX450 owners on their current hours and if they've had any issues. I have a few buddies with 2021/2022's and they have had no issues either.
oh i definitely find it strange man. where do you live in texas? I lived in Houston for a long time & did quite a bit of riding with the steers & queers.\
I do clutches quite a bit as well. What air filter oil & oil are you running? I do not think that should make a big difference as i'm not sucking dirt in & i'm using a good brand of oil, but just curious. Yeah not pumped on the bike breaking but sometimes shit just happens. I know of a few brand new ktm 450's in shops for blowing motors at 30 hours. I feel like sometimes it's just part of the game....
The only way a rod small end can get like that is no oil. Normal wear will just cause increased clearance as metal wears away. Scoring is a sign of oil loss. Everything in these motors is just aluminum and steel running on a thin layer of oil. If the oil pump is starved,oil jet is blocked, filter in wrong or blocked filter-it will wear parts quick. I have a 90 hour 19 kx450 and had it since new and it’s been as reliable as any other bike. All I have done is suspension revalve, rekluse torq drive clutch plates,heavy springs, remap ecu, and pc slip on. Repairs have been-left intake valve wore at 70 hours-rebuilt head with all prox valves and rest oem parts. Put a new piston and timing chain in. Crank was within spec. 40 hours new seat foam and inner clutch hub. I grease bearings every 2-3 rides and still all original linkage swingarm and steering bearings. I use 15w40 mag 1 diesel oil and oem filters and change every ride or two. Lots of normal wear items like chains,sliders,rotors,etc. but that is any bike. I did swap out the aluminum peg mounts for steel ones from an 18 kx450. Suspension I change fluids every 20 hours and seal/bushings at 40. Feels good as when I bought it but I do a lot of maintenance on it. I plan on waiting to get a 24 and keeping this. I like this chassis and suspension. My only wish for the 24 would be better front brake, little more power and better mapping. Oh..and a smaller muffler.
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How does you guys clutch basket look? I put plates and a spring in at 28 hours and noticed a good amount of wear.
Does anyone make a guard for the rear master cylinder? Mine is wearing badly, will probably have to replace by 50 hours.
Yeah I maintain my bike meticulously so it’s pretty frustrating. Do you think PC would be able to tell me about the oil pump or jets blocked or clogged?
when you say filter in wrong or blocked filter do you mean the standard oil filter? I use OEM & change it a lot. Or do you mean one of the filters inside the motor?
It is frustrating and I hate to hear of issue like that. The paper filter can be installed backwards. It will not feed oil. I have seen people use stainless filter and it impeded flow enough to cause damage.Yes-jets can be blocked and they should be able to tell you. The internal filters need to be checked. Even if the bike is laying on its side after a crash it can starve oil. The filtering setup is good on the kx, but if it gets blocked-it will not feed oil. The oil pump is made well, but the way the cylinder head and crank is on these bikes-all it takes is a couple seconds without oil flowing and it will damage them. It would be worthwhile to tear the engine down and find the reason for the damage.
Thank you for the info! I just got a crate motor put in to get me back on track. Not exactly sure what I’m doing to do with this motor yet but if we diagnose an issue I’ll update you.
While im now sponsored by Luxon, I tried two different brands first, and preferred the Luxon. So that’s who I reached out to for support and im thankful they came on board my program this year.
A lot of aftermarket clamps are to rigid for my liking, and I preferred the Luxon as it wasn’t too stiff
Cool , good luck this weekend
Where did you buy the crate motor? Price? Thanks!
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