Is the 2021 Honda water pump cover + Y-pipe held together with magic?

mtl
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mtl
Edited Date/Time 10/23/2021 2:06pm
Hey all,
I did the top end on my 2021 CRF250R and first ride one it the Y-pipe keeps popping out of the water pump cover and weeping coolant. I didn't remove it when I worked on the bike but it might have gotten bumped. I tried to tap it back in but it keeps popping out.


I thought it might be an o-ring, but looking at the exploded diagram it's an entire assembly (cover + Y-pipe).


Any ideas on how to fix? (Other than buying the entire assembly)

Or has anyone had this happen to them?

Thanks!


|
mtl
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mtl 9/27/2021 1:50pm
9/27/2021 1:50pm
Anyone?

Bueller?

If there is a better forum to post this, please let me know.
lostboy819
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lostboy819 9/27/2021 2:12pm
9/27/2021 2:12pm Edited Date/Time 9/27/2021 6:41pm
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water pump cover. If you bought it used then go to Honda dealer and buy a new water pump cover. $66 for new cover is cheap.

Edit: its looks like you bought it used so you will need to replace the water pump cover. more than likely got damaged in a crash at some point and only way to fix it is to replace it.
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4DAIVIPAI2K5
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4DAIVIPAI2K5 9/27/2021 3:28pm
9/27/2021 3:28pm
lostboy819 wrote:
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water...
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water pump cover. If you bought it used then go to Honda dealer and buy a new water pump cover. $66 for new cover is cheap.

Edit: its looks like you bought it used so you will need to replace the water pump cover. more than likely got damaged in a crash at some point and only way to fix it is to replace it.
If that's the case I would try silicone on it first, if that didn't work buy a new one.
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mtl
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mtl 9/27/2021 3:36pm
9/27/2021 3:36pm
lostboy819 wrote:
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water...
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water pump cover. If you bought it used then go to Honda dealer and buy a new water pump cover. $66 for new cover is cheap.

Edit: its looks like you bought it used so you will need to replace the water pump cover. more than likely got damaged in a crash at some point and only way to fix it is to replace it.
Thanks for the reply.

I bought it new, put about 30hrs on it and then did a top end.

The y-pipe started popping out after I did the top end, it was fine before then.

Just so I am armed with information, are you recommending I ask Honda to replace the cover because there is some known Honda defect?

Again, thanks for the reply.
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spimx
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spimx 9/27/2021 3:37pm
9/27/2021 3:37pm
Jb weld it
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hubbardmx50
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hubbardmx50 9/27/2021 3:48pm
9/27/2021 3:48pm Edited Date/Time 9/27/2021 3:52pm
Just replace it. $58 on Rocky Mountain
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Falcon 9/27/2021 4:06pm
9/27/2021 4:06pm
Dirtydeeds wrote:
Looks like a good spot for some duct tape
Silicone on the inside, duct tape on the outside. Reinforced with baling wire and a zip tie for good measure.
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murph783
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murph783 9/27/2021 4:20pm
9/27/2021 4:20pm
lostboy819 wrote:
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water...
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water pump cover. If you bought it used then go to Honda dealer and buy a new water pump cover. $66 for new cover is cheap.

Edit: its looks like you bought it used so you will need to replace the water pump cover. more than likely got damaged in a crash at some point and only way to fix it is to replace it.
4DAIVIPAI2K5 wrote:
If that's the case I would try silicone on it first, if that didn't work buy a new one.
You must be a plumber…
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Yeti831
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Yeti831 9/27/2021 4:48pm
9/27/2021 4:48pm
Aren’t the Boyesen kits one piece?

Probably be a safe bet to go that route.
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UGOTBIT
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UGOTBIT 9/27/2021 5:10pm
9/27/2021 5:10pm
Loctite makes anaerobic retaining compounds for stuff like this, I had a similar issue with a pressed in coolant tube in a oil cooler housing on a GT500. I removed the hose barb, cleaned it and then re-installed with the sealer, Compound 620.
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Forty
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Forty 9/27/2021 5:28pm
9/27/2021 5:28pm
Top end at 30 hours?
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lostboy819
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lostboy819 9/27/2021 6:45pm
9/27/2021 6:45pm Edited Date/Time 9/27/2021 6:48pm
lostboy819 wrote:
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water...
Its a press fit, if its your first ride did you buy it new ? if yes take it back and Honda can replace the water pump cover. If you bought it used then go to Honda dealer and buy a new water pump cover. $66 for new cover is cheap.

Edit: its looks like you bought it used so you will need to replace the water pump cover. more than likely got damaged in a crash at some point and only way to fix it is to replace it.
mtl wrote:
Thanks for the reply. I bought it new, put about 30hrs on it and then did a top end. The y-pipe started popping out after I...
Thanks for the reply.

I bought it new, put about 30hrs on it and then did a top end.

The y-pipe started popping out after I did the top end, it was fine before then.

Just so I am armed with information, are you recommending I ask Honda to replace the cover because there is some known Honda defect?

Again, thanks for the reply.
No there is no know defect, but if it had popped out the first ride they should have covered it. But with 30 hours on it you will need to buy a new one. You can try to fix it with all the wrong ways people will recommend but save yourself some problems and do it the right way. You did something wrong when you did the top end to knock it loose, its usually crash damage that does them in. Hubbardmx50 found them for $58 and that is not bad at all.
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mtl
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mtl 9/27/2021 7:22pm
9/27/2021 7:22pm
lostboy819 wrote:
No there is no know defect, but if it had popped out the first ride they should have covered it. But with 30 hours on it...
No there is no know defect, but if it had popped out the first ride they should have covered it. But with 30 hours on it you will need to buy a new one. You can try to fix it with all the wrong ways people will recommend but save yourself some problems and do it the right way. You did something wrong when you did the top end to knock it loose, its usually crash damage that does them in. Hubbardmx50 found them for $58 and that is not bad at all.
Super helpful, thank you!
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davis224
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davis224 9/27/2021 7:27pm
9/27/2021 7:27pm
Forty wrote:
Top end at 30 hours?
AgentOrange wrote:
Beat me to it
Wonder how many top ends their daily driver is up to
Dirty Points 9/28/2021 6:40am
9/28/2021 6:40am
I can affirm the effectiveness of Loctite press fit retaining compound as mentioned above
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kibby
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kibby 9/28/2021 9:41am
9/28/2021 9:41am Edited Date/Time 9/28/2021 10:03am

Geico Honda engine , when using OE waterpump a small set screw was installed helping combat possible movement up/out of steel Y tube. Tube was also installed with some epoxy to help bond it in place.
These type of steel tube/pressed into cast Alum parts failures have been happening in MX bikes for decades.
Coolant hose spigots, Power valve breather hoses etc have all been problematic in 90's RM's 2000's YZ's etc and obviously now some CRF's.
Much like you might heat cases to open tolerances on an interference press fit bearing, when cast alum. parts get hot pressed in parts can loosen and come out.
Loctite products are great too but I don't think a silicone product will succeed in this application so I'd stay away from just choosing to use silcone on exterior of part. Keep in mind your system is under pressure at operating temps, 10+ psi and silicone will probably just push out of the way.
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Xeno
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Xeno 9/28/2021 11:08am
9/28/2021 11:08am
I learned something on Vital today!
Ironically, I was just talking to Mr. Aerospace aka TeamGreen the other day about this very issue. And his suggestion was a Loctite retaining compound. But he didn't have a reference number for the compound, so thanks UGOTBIT for the info.
I will be trying the Loctite 620, along with Kibby's set screw detail.
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Kenny Lingus
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Kenny Lingus 9/29/2021 9:41am
9/29/2021 9:41am
In all seriousness, how do you get it out without hurting it?
mtl
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mtl 9/29/2021 10:26am
9/29/2021 10:26am
Thank you to all the folks who provided some input. Given the performance nature of the motor, I ordered up a new assembly. Hopefully this isn't needed every time I do a top end.

Per kibby's recommendations, if I have time I will drill out the old one and install a set screw.


Sidenote, this is one of the most productive threads I've seen in this forum. Maybe I should lock it before it goes sideways. 😂
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kibby
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kibby 9/29/2021 10:48am
9/29/2021 10:48am
Kenny Lingus wrote:
In all seriousness, how do you get it out without hurting it?
Hold Aluminum part of pump cover gently in a vice with soft jaws.Heat with MAP gas and gently twist the Y pipe once alum part heated/expanded. Be sure to scribe a line across the two parts before beginning work so you can return the steel tube to it's correct clocked position.
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Kenny Lingus
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Kenny Lingus 9/29/2021 10:59am
9/29/2021 10:59am
Kenny Lingus wrote:
In all seriousness, how do you get it out without hurting it?
kibby wrote:
Hold Aluminum part of pump cover gently in a vice with soft jaws.Heat with MAP gas and gently twist the Y pipe once alum part heated/expanded...
Hold Aluminum part of pump cover gently in a vice with soft jaws.Heat with MAP gas and gently twist the Y pipe once alum part heated/expanded. Be sure to scribe a line across the two parts before beginning work so you can return the steel tube to it's correct clocked position.
Thanks. Haven't had a problem but I think I will do this over the winter.
Tracktor
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Tracktor 9/29/2021 12:48pm
9/29/2021 12:48pm
If you ever need a permanent sealant use some 3m 5200. Not necessarily recommending it for this fix but for repairs that need a silicone type sealant that you need to rely on to never come loose it's the shit..........
plowboy
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plowboy 9/29/2021 1:00pm
9/29/2021 1:00pm
This is an engineering design flaw...plain and simple. There are many ways this coupling could have been designed and the one they chose was poor. This could make a crafty aftermarket designer some bucks.
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PNWRider
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PNWRider 9/29/2021 1:42pm
9/29/2021 1:42pm
mtl wrote:
Thank you to all the folks who provided some input. Given the performance nature of the motor, I ordered up a new assembly. Hopefully this isn't...
Thank you to all the folks who provided some input. Given the performance nature of the motor, I ordered up a new assembly. Hopefully this isn't needed every time I do a top end.

Per kibby's recommendations, if I have time I will drill out the old one and install a set screw.


Sidenote, this is one of the most productive threads I've seen in this forum. Maybe I should lock it before it goes sideways. 😂
It’s not quite there yet. You’ll know it’s time when the fight over vaccination and politics starts…Laughing
PNWRider
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PNWRider 9/29/2021 1:45pm
9/29/2021 1:45pm
kibby wrote:
[img]https://p.vitalmx.com/photos/forums/2021/09/28/512223/s1200_waterpump.jpg[/img] Geico Honda engine , when using OE waterpump a small set screw was installed helping combat possible movement up/out of steel Y tube. Tube was...

Geico Honda engine , when using OE waterpump a small set screw was installed helping combat possible movement up/out of steel Y tube. Tube was also installed with some epoxy to help bond it in place.
These type of steel tube/pressed into cast Alum parts failures have been happening in MX bikes for decades.
Coolant hose spigots, Power valve breather hoses etc have all been problematic in 90's RM's 2000's YZ's etc and obviously now some CRF's.
Much like you might heat cases to open tolerances on an interference press fit bearing, when cast alum. parts get hot pressed in parts can loosen and come out.
Loctite products are great too but I don't think a silicone product will succeed in this application so I'd stay away from just choosing to use silcone on exterior of part. Keep in mind your system is under pressure at operating temps, 10+ psi and silicone will probably just push out of the way.
As I recall, Brian Lunnis talked about an RC250 DNF-ing because of such a pressed-in fitting on his Whiskey Throttle episode.

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