2018 crf250r smoking out of right exhaust only

Beasley78
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Des Moines, IA US
11/28/2018 7:48pm Edited Date/Time 11/29/2018 8:41pm
What would make my bike smoke only out of the right side.
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Beasley78
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Des Moines, IA US
11/28/2018 9:00pm Edited Date/Time 11/28/2018 9:14pm
Beasley78
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11/28/2018 9:13pm
[img]https://p.vitalmx.com/photos/forums/2018/11/28/306215/s1200_AA1B8F6D_E0D4_44DC_8891_7ACDC6B59C11.jpg[/img] Worn valve guide


Worn valve guide
The head and valves are brand new. New rings, new base and head gasket also. It didn't smoke before the dealership did the clutch recall.
colvin227
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Alamogordo, NM US
11/28/2018 10:47pm
Is it a brand new bike or a new rebuild? Did you get the recall done same time as the rebuild?

The Shop

kb228
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11/29/2018 3:12am
Smoking out of the right side only makes me suspect your right side exhaust valve stem seal. Oil from in your head is leaking thru on that side and burning off. If it were anything else it would be smoking out of both sides.

Nothing clutch related should affect your top end.
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Beasley78
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11/29/2018 11:04am
colvin227 wrote:
Is it a brand new bike or a new rebuild? Did you get the recall done same time as the rebuild?
It's a long story this bike has been nothing but trouble since I bought it. It has been a hard starting bike since day one. Then one day the bike would not turn over. I checked the battery and it was at 95%. So I took it back to the dealership They told me that the bike was liquid locked and they blamed it on a bad head gasket caused by the 1.6 radiator cap I had on it. They had the bike almost a month and they also did the recall while it was there. They wanted to charge me 600 to put it back together so I said don't I can put it back together myself. So I put it back together and while doing so I found that the intake boot going from the throttle body to the head was cracked on the bottom. So I put a new one on and reassembled the bike and it starts right up but it was burning coolant. The head was cracked. So that's why is has a new head. I put new rings on while I had it apart , new valves and new valve stem seals and all new gaskets and yet it still smokes out of the right side only. I did a leak down test and the valves are all sealed nicely
1
kb228
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11/29/2018 11:14am
Like i said, your exhaust valve stem seal on the right side is bad. If you didnt push it onto the guide all the way it could have popped back off.
2
colvin227
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11/29/2018 12:52pm
kb228 wrote:
Like i said, your exhaust valve stem seal on the right side is bad. If you didnt push it onto the guide all the way it...
Like i said, your exhaust valve stem seal on the right side is bad. If you didnt push it onto the guide all the way it could have popped back off.
X2....this was my thought as well. oil is slipping by the seal and running down the valve and burning off and smoking out the pipe. Pull the valve cover and give a look in there. Does it smoke constantly or does it subside at all, or is it like bellows of smoke constantly out the right pipe until you shut it down? Any audible weird noises (ticking, tapping) accompanied with the oil? Too bad sounds like its been a mess for you bud
1
Beasley78
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11/29/2018 3:01pm
colvin227 wrote:
X2....this was my thought as well. oil is slipping by the seal and running down the valve and burning off and smoking out the pipe. Pull...
X2....this was my thought as well. oil is slipping by the seal and running down the valve and burning off and smoking out the pipe. Pull the valve cover and give a look in there. Does it smoke constantly or does it subside at all, or is it like bellows of smoke constantly out the right pipe until you shut it down? Any audible weird noises (ticking, tapping) accompanied with the oil? Too bad sounds like its been a mess for you bud
When first started it doesn't smoke at all but as it warms up it starts to smoke more and gets worse. Everything sounds normal I will check the seals but I just installed the valves and new stem seals. The bike did the same thing with the old head as well but was also loosing coolant. This thing has been a nightmare for me.
kb228
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Mansfield, OH US
11/29/2018 3:27pm
If it was burning coolant the smoke would come out of both sides. If it were burning anything before the exhaust valve it would come out both sides. Something is burning in the exhaust valve. Its oil. Nothing else can get into it.
1
kb228
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11/29/2018 3:28pm
Also just so we arent overlooking something dumb, you dont have any oil in your packing do you?
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BRX-WRX
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Blue Springs, MO US
11/29/2018 8:16pm
As all have said above is great advice. It might just be burning the oil in pipe and packing from your previous problem. You said it starts smoking after it warms up ? Remove that side exhaust soak it in solvent tank or rinse with kerosene and burn it out. The exhaust above head is separated. That would be valve seal or oil still in exhaust. This may help you narrow it down. Its the slow season for me so I have had more time to read Vital. Theirs some sharp guys/galls on here that I enjoy reading.
Beasley78
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11/29/2018 8:41pm
Thank you all for your feed back it's greatly appreciated
Gile
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12/27/2022
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Kraljevo RS
12/27/2022 4:03am

Hello guys , I have the same problem with mine crf 2018 , did somebody find some solution ? im suspecting to piston rings , because piston is in factory spec and the head is seems fine ...thanks in front

wrc777
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12/27/2022 11:05am
Gile wrote:
Hello guys , I have the same problem with mine crf 2018 , did somebody find some solution ? im suspecting to piston rings , because...

Hello guys , I have the same problem with mine crf 2018 , did somebody find some solution ? im suspecting to piston rings , because piston is in factory spec and the head is seems fine ...thanks in front

Is it smoking out one side of the exhaust or both?

Gile
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Kraljevo RS
12/28/2022 1:39am

It is smoking and spitting oil only on right exhaust, valves are fine , valve seals new , by the carbon on the right exhaust valve (any other valve is clean) i could tell that is coming from the combustion chamber, cilinder is good , piston is 0.05 from cilinder which i think is also fine , only thing that I could notice is that the compression ring joint was near to that valve, so I`m suspecting on the piston rings... the engine worked fine before , I changed con rod, bearings etc ... didn`t change the piston and after assembling it started acting like that ... saw this thread with the same problem so I`m curious did Beasley sorted it out...cheers

harescrambled
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12/29/2022 4:35pm Edited Date/Time 12/29/2022 4:36pm
Gile wrote:
It is smoking and spitting oil only on right exhaust, valves are fine , valve seals new , by the carbon on the right exhaust valve...

It is smoking and spitting oil only on right exhaust, valves are fine , valve seals new , by the carbon on the right exhaust valve (any other valve is clean) i could tell that is coming from the combustion chamber, cilinder is good , piston is 0.05 from cilinder which i think is also fine , only thing that I could notice is that the compression ring joint was near to that valve, so I`m suspecting on the piston rings... the engine worked fine before , I changed con rod, bearings etc ... didn`t change the piston and after assembling it started acting like that ... saw this thread with the same problem so I`m curious did Beasley sorted it out...cheers

.05mm piston to cylinder is the correct clearance. If you've got carbon on one valve, and no others, you either have a bad stem seal, or the valve stem or guide are worn to the point it's allowing the valve to rock enough to allow the stem seal to leak. It is possible (and somewhat common) to damage valve stem seals when installing them over used valves. The stem tips eventually develop a sharp edge or burr from use. This tends to cut stem seals (and scratch up valve guides) when installing.

If the rings were bad, you'd have carbon on both exhaust valves, and it would smoke all the time

Gile
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Kraljevo RS
12/31/2022 1:39am

the bike was fine , I checked valves and it was out of spec , too much clearence , put it to the spec and assemble the engine and after that it started smoking and spitting

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