Upgrade to enjoy this feature!
Vital MX fantasy is free to play, but paid users have great benefits. Paid member benefits:
- View and download rider stats
- Pick trends
- Create a private league
- And more!
Only $10 for all 2024 SX, MX, and SMX series (regularly $30).
The Shop
. He already has his new 21 YZ 450...
He logged 85 hours on his 20 model...put a piston and rings in at 50 hours but said it didn't need it...but he was alarmed to find that a valve spring collett had popped out...amazingly it didnt cause any damage, so he replaced that valve,the spring retainer and collets to be safe.
He runs the stock filter setup also..
He is a very fast rider, but I wouldn't say he was hard on the bike, he's very smooth and carries momentum very well.
My young mate however..the one that broke his con rod and totalled the motor at 6 hours is a bonefide bike wrecker...very fast A grader, just an animal on the bike...
May e valve spring collects jumping out is a thing?
I have the twin air kit. I scrub loose dirt off the filter, remove it, clean the air filter area by hand, throw a wash cover on, power wash it, dry it, pull off the shrouds to make it easier to install the filter, make sure there is no dirt in the box, and then install a fresh one.
I wouldn’t do a fresh filter between motos. Whatever performance gains you’re getting is not worth risking dirt from the air box area getting knocked in there while installing a new filter.
Unless it’s reallly dusty / muddy / sandy, I just wash my bike every other ride and do that filter routine. It’s typically not dirty after 1 ride and I don’t want to risk water dropping down there while I wash it.
we do 3hrs races in sand with same air filter so it’s not a question about that. By the color of your oil I’d like to know what kind of oil you use tho ? For me it’s looks like your oil is not good at all and the cams bearings just locked, broke ..
Pit Row
My 17 had over 200 hours, my 15 had over 150 hours, my 14 had over 150 hours, my 13, my 11, my 09, my 08, my 07, my 05, my 03... etc, etc, etc back to 08 400 had over 250 hours. Never once have I ever replace ANYTHING transmission related.... Even the 14 that I blew up cause of the faulting rod issue that Yamaha had a recall on, never did any damage to the transmission.
So you would understand why I would be interested in a transmission issue.
I do know the 14s had the shift lever detent arm that had the ball bearing roller that would fail and ball bearings would fall into the transmission but they fixed those on the 15 or 16 and there was a bulletin on them and Yamaha would replace the part for free.
And again, not questioning anybody, I just would really love to hear what the issue was and see what caused it.
For both bearings to seize and cam journals being destroyed on both the right side of the head, it was 100% oil issue.
Again I do not mean to sound rude, I m just trying to share 40 years of bike mechanics. If you are a fast B rider and probably any level A rider, the cam chain and tensioner MUST be changed on these bikes at EVERY top end. In fact, those 2 parts are probably MORE important then the piston and rings.
I would also like to add that again judging by this picture, this motor has been disassembled before as I do not recognize the red anti seize (if that's what it is) on the threads of the bolt hole on the cam chain side of the head as a type of product Yamaha uses from the factory. However I could be wrong.
To the OP, was this motor rebuild in the past?
Both mentioned that oil filter is easy tu put in backwards..
There is a hole in 1 side of the oil filter, if you are putting these in backwards you would literally have to punch a hole in the other side to do that. I find it really hard to comprehend someone is putting the filter in backwards..... and even if they did, it would not cause damage to the motor, it simply would not filter properly.
Edit: YZ450F 2020
Oil change 0.63L
Oil & filter change 0.65L
Post a reply to: 2020 yz450f problems