2018 YZ450F 3rd Gear Slipping

foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
5/29/2018 12:24pm Edited Date/Time 1/14/2019 8:55am
Hi all,

I have a 2018 YZ450F, approx 6-7 hours on it. Replaced the clutch after my last ride out...felt like it was slipping. Put a new one in it today and didn't solve the problem (original clutch still fine). It's very evident that when in third gear and get on the throttle it skips. All other gears are fine.

I'm wondering if anyone has had this issue yet. I have seen lots of starter problems but no transmission issues. I race as a regional pro here in Canada so I am not just some random Joe Blow LOL. I run the bike high sticking between third and fourth 95% of the time.

Thanks for any help you contribute
|
flomiester
Posts
188
Joined
2/10/2012
Location
Elwell, MI US
5/29/2018 3:17pm
The engagement dogs are rounded off in 3rd gear you can send the trans to R&D performance and have it made better than new
swtwtwtw
Posts
1287
Joined
4/16/2008
Location
Apple Valley, CA US
5/29/2018 5:47pm
What oil is in it? I can for certain feel slipping with a certain brand on mine. And it happens to be my favorite and did not cause slipping with my previous years husqvarna
Paw Paw 271
Posts
3640
Joined
4/3/2013
Location
Benton, LA US
5/29/2018 7:31pm
swtwtwtw wrote:
What oil is in it? I can for certain feel slipping with a certain brand on mine. And it happens to be my favorite and did...
What oil is in it? I can for certain feel slipping with a certain brand on mine. And it happens to be my favorite and did not cause slipping with my previous years husqvarna
X2

Paw Paw
Lynch
Posts
722
Joined
3/14/2015
Location
SE
5/29/2018 9:36pm
Paw Paw and swtwtwtw, can you guys elaborate on what oil would cause slipping? I have heard about it before however never had any problems myself, looking to buy a Yamaha soon and would be nice to know.

The Shop

mx317
Posts
4531
Joined
4/1/2008
Location
TN US
5/30/2018 5:39am
If you have a 3rd gear shiftfork bent and it's rounded off the gears, then changing to a different oil won't fix it. Now if it's the clutch, it might.
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
5/30/2018 6:30am Edited Date/Time 5/30/2018 6:38am
Yamalube 10W40...same stuff I have been running for years. I am certain it is not an oil or clutch related.

Once you shift into third gear and get on the gas hard it slips. It feels as if something is not catching. I'm pretty positive this is a transmission issue, but I just wanted to see if anyone has had this issue yet.
5/30/2018 6:50am
foreman52 wrote:
Yamalube 10W40...same stuff I have been running for years. I am certain it is not an oil or clutch related. Once you shift into third gear...
Yamalube 10W40...same stuff I have been running for years. I am certain it is not an oil or clutch related.

Once you shift into third gear and get on the gas hard it slips. It feels as if something is not catching. I'm pretty positive this is a transmission issue, but I just wanted to see if anyone has had this issue yet.
Slips? When my YZ lost third year it didn't slip. It would hit a false neutral or just jump out of gear. There was no doubt what was going on. My third year has went out three times. I finally sent the internals of the entire transmission and had them cryo-rem treated. No worries since.
dedi684
Posts
1350
Joined
8/21/2009
Location
Ravena, NY US
5/30/2018 7:54am
foreman52 wrote:
Yamalube 10W40...same stuff I have been running for years. I am certain it is not an oil or clutch related. Once you shift into third gear...
Yamalube 10W40...same stuff I have been running for years. I am certain it is not an oil or clutch related.

Once you shift into third gear and get on the gas hard it slips. It feels as if something is not catching. I'm pretty positive this is a transmission issue, but I just wanted to see if anyone has had this issue yet.
Slips? When my YZ lost third year it didn't slip. It would hit a false neutral or just jump out of gear. There was no doubt...
Slips? When my YZ lost third year it didn't slip. It would hit a false neutral or just jump out of gear. There was no doubt what was going on. My third year has went out three times. I finally sent the internals of the entire transmission and had them cryo-rem treated. No worries since.
This happened on my yz 250
swtwtwtw
Posts
1287
Joined
4/16/2008
Location
Apple Valley, CA US
5/30/2018 8:23am Edited Date/Time 5/30/2018 8:23am
Yams lube is good. However, when a gear goes the trans hits a false neutral. If I overrev this bike it falls flat on its face, anything above 8000 rpm with the Preston map. That alone feels like clutch slippage.
mx317
Posts
4531
Joined
4/1/2008
Location
TN US
5/30/2018 8:33am
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a very loose chain jumping over the sprocket teeth. This happens when the "dogs" on the gears are rounded off which usually is accompanied with a bent shift fork.
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
5/30/2018 9:04am
swtwtwtw wrote:
Yams lube is good. However, when a gear goes the trans hits a false neutral. If I overrev this bike it falls flat on its face...
Yams lube is good. However, when a gear goes the trans hits a false neutral. If I overrev this bike it falls flat on its face, anything above 8000 rpm with the Preston map. That alone feels like clutch slippage.
This would be the best explanation to what I've been experiencing thus far.

I wouldn't say it's exactly like "hitting false neutral" because when that happens we almost go over the bars, but it's certainly a feeling like that. It looses power when hitting a high RPM and than it corrects itself and you almost whisky throttle over backwards because all of a sudden the power hits of all at once
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
5/30/2018 9:56am
mx317 wrote:
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a...
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a very loose chain jumping over the sprocket teeth. This happens when the "dogs" on the gears are rounded off which usually is accompanied with a bent shift fork.
Now would you see metal shavings in the oil if this was the case? There was no signs of anything in the oil.
kb228
Posts
6161
Joined
1/31/2018
Location
Mansfield, OH US
5/30/2018 10:10am
FWIW, 3rd gear seems to provide the most power on all the bikes ive ridden. Its quite possible you need stiffer clutch springs from hinson or something.

Also maxima and amsoil full synthetic dirtbike oil is the only one that prevents slipping - in my experience.
mx317
Posts
4531
Joined
4/1/2008
Location
TN US
5/30/2018 11:04am
mx317 wrote:
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a...
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a very loose chain jumping over the sprocket teeth. This happens when the "dogs" on the gears are rounded off which usually is accompanied with a bent shift fork.
foreman52 wrote:
Now would you see metal shavings in the oil if this was the case? There was no signs of anything in the oil.
Then it's probably not that.
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
5/30/2018 11:14am
mx317 wrote:
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a...
I've seen gears go and like the above posters said, "it's like a false neutral". I've also had them go out where it felt like a very loose chain jumping over the sprocket teeth. This happens when the "dogs" on the gears are rounded off which usually is accompanied with a bent shift fork.
foreman52 wrote:
Now would you see metal shavings in the oil if this was the case? There was no signs of anything in the oil.
mx317 wrote:
Then it's probably not that.
Thanks for your input. I will post the solution once we open it up! Some of the smartest people I know are scratching their heads. A few think it's what you mentioned and than the others are saying the complete opposite. It's a mystery I wish I never had!
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
6/5/2018 8:44am
Still no updates. Bike has been at the Yamaha dealership for two days. They have tried multiple solutions including putting a whole new computer in the bike. The motor has not been taken out yet, but Yamaha does not believe it's an issue with the transmission.
6/5/2018 9:15am
kb228 wrote:
FWIW, 3rd gear seems to provide the most power on all the bikes ive ridden. Its quite possible you need stiffer clutch springs from hinson or...
FWIW, 3rd gear seems to provide the most power on all the bikes ive ridden. Its quite possible you need stiffer clutch springs from hinson or something.

Also maxima and amsoil full synthetic dirtbike oil is the only one that prevents slipping - in my experience.
I like this advice.

Also, I suggest buying a magnetic drain plug. All three times my YZ tranny went out there was not a lot of stuff on the magnetic drain plug, but there was more than usual. Or, you could filter the oil through cheese cloth and see what you get. Maybe you're doing these things already and I'm just not able to parse it out of your posts, but those are a couple of suggestions.

Kb is right about third gear too. That's where my YZ 250 makes the most power, and it has always been the gear the dogs round off on. I don't know about the four strokes, but it takes hardly any wear on my smoker's 3rd gear dogs for it to start jumping into a false neutral. In fact, the first time I took it apart I looked at them and thought they were fine. Put it back together and the same problem immediately (that was a painful lesson for sure). Anyhow, once I got the new third gear and saw the difference in the dog ears it was noticeable, but still not very much had worn. Like I said, it doesn't take much. Good luck to you, motobro.
mattyhamz2
Posts
10850
Joined
7/6/2015
Location
So Cal, CA US
Fantasy
760th
6/5/2018 10:01am
Lost 3rd gear twice on my 05 kx250f and it's like hitting a false neutral. Bike wouldn't move at all if I shifted into 3rd, just felt as though the chain was skipping teeth on the sprocket like someone else had said. Had to run 2nd and shift to 4th. You'd know if it was 3rd gear going out. Hope they figure the issue out quick
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
6/13/2018 6:19pm
We're two weeks in here now and nothing has been resolved. My local dealer has bent over backwards trying to get it fixed. The service from Yamaha has been completely unacceptable. This is my third Yamaha in three years...my 2016 YZ250F needed the valves replaced twice (both at 20 hours), my 2017 YZ250F needed the valves done at 30 hours, and now I am having this issue with my new 18. My faith with Yamaha has gone completely out the window. I can't deny that it is a powerful and good feeling bike but my god watching my buddies on other brands not having to worry about issues like this makes you think.
1
lumpy790
Posts
9145
Joined
9/18/2007
Location
York, SC US
6/14/2018 5:58am
What rpm range is it breaking down?

Sounds electrical but I have never see a CDI controle unit go bad it is typically something feeding it the info that goes bad.

What have they tried from the simple end? Check all connections and Electrical grease in all connections? Would assume Spark plug has been tried? Spark plug cap? Thermo unit? Neutral switch Assembly? Engine controle unit?

I would get the bike back and find someone that has the 18 and swap out the parts till you find the culprit




foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
6/14/2018 12:38pm
Every electrical component has been swapped off another brand new bike in the showroom. The issue is still persisting. This now eliminates anything electrical, which almost everyone thought it was. Looks like we will be opening the motor up now...Hopefully I will be back in a week with an update.
swtwtwtw
Posts
1287
Joined
4/16/2008
Location
Apple Valley, CA US
6/14/2018 4:44pm
Well, here’s to the solution. Mine is better now at 30 hrs than ever. I have been testing Rock Oil synthetic and my clutch performance is better than with my favorite synthetic.
lumpy790
Posts
9145
Joined
9/18/2007
Location
York, SC US
6/14/2018 5:09pm
Ok i will as again ....
What rpm range is it breaking down?
foreman52
Posts
629
Joined
5/29/2018
Location
CA
Fantasy
3155th
6/14/2018 5:21pm Edited Date/Time 6/14/2018 5:22pm
lumpy790 wrote:
Ok i will as again ....
What rpm range is it breaking down?
https://www.youtube.com/watch?v=3X4QQazAsmk

Get it home while it's raining of course so pavement is wet. Here is an idea of what it's doing. I wish I could get a video opening it up more. You can hear/see as soon as I get on the throttle hard it "skips".
Hondas4Life3
Posts
853
Joined
7/30/2013
Location
Louisburg, KS US
6/14/2018 8:03pm Edited Date/Time 6/14/2018 8:08pm
foreman52 wrote:
https://www.youtube.com/watch?v=3X4QQazAsmk Get it home while it's raining of course so pavement is wet. Here is an idea of what it's doing. I wish I could get...
https://www.youtube.com/watch?v=3X4QQazAsmk

Get it home while it's raining of course so pavement is wet. Here is an idea of what it's doing. I wish I could get a video opening it up more. You can hear/see as soon as I get on the throttle hard it "skips".
Sounds like 3rd gear is blown to me. Doesn't sound like a clutch, clutch would be more of a progressive slip and electrical I think would cut out instead of "skip"
Matt Fisher
Posts
3947
Joined
4/1/2008
Location
Visalia, CA US
Fantasy
1084th
6/15/2018 1:33pm
foreman52 wrote:
https://www.youtube.com/watch?v=3X4QQazAsmk Get it home while it's raining of course so pavement is wet. Here is an idea of what it's doing. I wish I could get...
https://www.youtube.com/watch?v=3X4QQazAsmk

Get it home while it's raining of course so pavement is wet. Here is an idea of what it's doing. I wish I could get a video opening it up more. You can hear/see as soon as I get on the throttle hard it "skips".
Sounds like 3rd gear is blown to me. Doesn't sound like a clutch, clutch would be more of a progressive slip and electrical I think would...
Sounds like 3rd gear is blown to me. Doesn't sound like a clutch, clutch would be more of a progressive slip and electrical I think would cut out instead of "skip"
Yep. Mechanical issue. Shift fork or the gears themselves. Very small possibility the shift drum has a problem.
kb228
Posts
6161
Joined
1/31/2018
Location
Mansfield, OH US
6/15/2018 1:42pm
Did you take the time to tear the right side apart? That star thing on the drum could be worn out. Or if its pre-rounded as previously mentioned, the tensioner spring might be too weak to hold it.
lumpy790
Posts
9145
Joined
9/18/2007
Location
York, SC US
6/16/2018 11:49am
Any metal in the oil filter? Trans would leave metal shrapnel. Oil pump filter?
nch209
Posts
417
Joined
1/1/2017
Location
NoVa, VA US
6/16/2018 1:26pm
flomiester wrote:
The engagement dogs are rounded off in 3rd gear you can send the trans to R&D performance and have it made better than new
I vote this as well. Happened to a low hour YZ250 a few years back. Split, replace, rebuild and good to go. Good Luck

Post a reply to: 2018 YZ450F 3rd Gear Slipping

The Latest