2018 YZ450F Skipped Timing

kb228 wrote:

Ladies and gentlemen, your 2019 shootout winner. Haha

fourfourone wrote:

so odd because 14-17 were known to be bullet proof. up here in the North east so many people ride YZs, I see a ton of...

so odd because 14-17 were known to be bullet proof. up here in the North east so many people ride YZs, I see a ton of new ones at the track too. Certainly in no rush to sell my 17.

kb228 wrote:

Ladies and gentlemen, your 2019 shootout winner. Haha

fourfourone wrote:

so odd because 14-17 were known to be bullet proof. up here in the North east so many people ride YZs, I see a ton of...

so odd because 14-17 were known to be bullet proof. up here in the North east so many people ride YZs, I see a ton of new ones at the track too. Certainly in no rush to sell my 17.

mattyhamz2 wrote:

My 14 was great. Never any issues. My buddy has a 17 with no problems either. I know a bunch of guys with 18's that have...

My 14 was great. Never any issues. My buddy has a 17 with no problems either. I know a bunch of guys with 18's that have never had any issues with theirs either.

fourfourone wrote:

so odd because 14-17 were known to be bullet proof. up here in the North east so many people ride YZs, I see a ton of...

so odd because 14-17 were known to be bullet proof. up here in the North east so many people ride YZs, I see a ton of new ones at the track too. Certainly in no rush to sell my 17.

mattyhamz2 wrote:

My 14 was great. Never any issues. My buddy has a 17 with no problems either. I know a bunch of guys with 18's that have...

My 14 was great. Never any issues. My buddy has a 17 with no problems either. I know a bunch of guys with 18's that have never had any issues with theirs either.

Jbulz wrote:

I was surprised for sure. I know all bikes have problems and shit happens sometimes. I always associated Yamaha with reliability and was surprised to see...

I was surprised for sure. I know all bikes have problems and shit happens sometimes. I always associated Yamaha with reliability and was surprised to see how much of a runaround they gave him getting it covered. Ended up covering some parts but I think it still ended up costing him almost $1500 out of pocket.

His backup bike was a 2015 with like 100 hours that seems like it was pretty bulletproof. I noticed it blowing smoke out the crankcase breather at the end of the season though so we tore it down and found a cracked piston across the top of the crown that was just about to ready to let go. Threw a new one in and it was fine lol. Luckily caught it early enough!

I thought it was a weird way to crack - I've seen them run across the crown in line with the wrist pin, but not front to back.

mattyhamz2 wrote:

My 14 was great. Never any issues. My buddy has a 17 with no problems either. I know a bunch of guys with 18's that have...

My 14 was great. Never any issues. My buddy has a 17 with no problems either. I know a bunch of guys with 18's that have never had any issues with theirs either.

Jbulz wrote:

I was surprised for sure. I know all bikes have problems and shit happens sometimes. I always associated Yamaha with reliability and was surprised to see...

I was surprised for sure. I know all bikes have problems and shit happens sometimes. I always associated Yamaha with reliability and was surprised to see how much of a runaround they gave him getting it covered. Ended up covering some parts but I think it still ended up costing him almost $1500 out of pocket.

His backup bike was a 2015 with like 100 hours that seems like it was pretty bulletproof. I noticed it blowing smoke out the crankcase breather at the end of the season though so we tore it down and found a cracked piston across the top of the crown that was just about to ready to let go. Threw a new one in and it was fine lol. Luckily caught it early enough!

I thought it was a weird way to crack - I've seen them run across the crown in line with the wrist pin, but not front to back.

mattyhamz2 wrote:

The fact that he went almost or over 100 hours on a piston in a 250f unreal. That says something about their product. Not that it...

The fact that he went almost or over 100 hours on a piston in a 250f unreal. That says something about their product. Not that it isn't possible, but no way in hell would I go over 40-50 hours on a piston in a 250f! Lol. 450's all day long, but never a 250f. Too high revving for me to even test it that far again. I got over 100 on my 05 kx250f before we replaced it. We will never ever do that again in a 250f! It held up, but it was not smart of us haha.

Jbulz wrote:

I was surprised for sure. I know all bikes have problems and shit happens sometimes. I always associated Yamaha with reliability and was surprised to see...

I was surprised for sure. I know all bikes have problems and shit happens sometimes. I always associated Yamaha with reliability and was surprised to see how much of a runaround they gave him getting it covered. Ended up covering some parts but I think it still ended up costing him almost $1500 out of pocket.

His backup bike was a 2015 with like 100 hours that seems like it was pretty bulletproof. I noticed it blowing smoke out the crankcase breather at the end of the season though so we tore it down and found a cracked piston across the top of the crown that was just about to ready to let go. Threw a new one in and it was fine lol. Luckily caught it early enough!

I thought it was a weird way to crack - I've seen them run across the crown in line with the wrist pin, but not front to back.

mattyhamz2 wrote:

The fact that he went almost or over 100 hours on a piston in a 250f unreal. That says something about their product. Not that it...

The fact that he went almost or over 100 hours on a piston in a 250f unreal. That says something about their product. Not that it isn't possible, but no way in hell would I go over 40-50 hours on a piston in a 250f! Lol. 450's all day long, but never a 250f. Too high revving for me to even test it that far again. I got over 100 on my 05 kx250f before we replaced it. We will never ever do that again in a 250f! It held up, but it was not smart of us haha.

Jbulz wrote:

Well that was a 450 too lol. 100 hrs is about what I'd expect a stock 450 to go, so I'm not saying anything bad about...

Well that was a 450 too lol. 100 hrs is about what I'd expect a stock 450 to go, so I'm not saying anything bad about the reliability on this bike.

jbyrd494 wrote:

What was the final outcome with your issues? Having a couple of issues with my 2018 yz450f, i have around 32 hours on the bike. First...

What was the final outcome with your issues?


Having a couple of issues with my 2018 yz450f, i have around 32 hours on the bike.

First my chain snapped under moderate throttle coming out of a corner, destroyed my front sprocket and luckily only nicked the case and no further damage was done. \

Now i believe the starter clutch has gone out because whenever i hit the electric start button i can just hear the starter spinning while making a high pitched whine and the motor isnt cranking at all. I bump started the bike last night and then the starter worked afterwards. I had already took the day off to go ride this morning so i figured i would test my luck with the starter. When i went to start it at the track this morning i had the same issue. I said screw it i will just bump start it that way i can still ride for the day.

Well, about 30 attempts later ( took 1 or 2 last night ) i finally get the bike started and out on the track i go. I just replaced my front and rear tire yesterday for todays ride. When i got out on the track the bike seemed to be a little off but i thought maybe it was just me not being used to the new tires. (went from mx3s to sand 5) . After riding a little longer i realized the bike was slipping in third gear. I could give the bike a nice throttle roll in 3rd gear and just feel it almost hopping like it jumped a couple teeth on the sprocket. I pulled off the track checked the chain tension and both sprockets and eveything looked great (less than 5 hours on chain and sprocket set. So i go to exit the track and i pull off in 2nd gear and i can feel the bike doing the same thing in 2nd. I said screw it and loaded up for the day. Dealer is acting like they have never had an issue with the starter clutches come in to them on these 18's which i know is bs. My biggest question is are these things directly correlated ? Or do i have two separate issues that happen to present themselves at the same time? Never had a bike newer than an 18 so all of this electric start is new to me.

I have seen some people say use full synthetic and it might stop the slipping? is this accurate? I currently run synblend4 50/50.

Any insight is greatly appreciated. Thanks