yz250f 21 reliability?

MadsDausel
How does your bike hold op?

Mine broke a 2 hour conrod and I have talk to many with broken conrods

I think a lot about whether to build it up and sell or try and race on it again.

The bike has ported head and higher compression, akrapovic pipe and vortex ecu.
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AH387
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AH387 6/16/2022 12:46pm
6/16/2022 12:46pm
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially a cause of some of these failures people are having. Just for clarification the rod went within 2 hours when it was stock? Or within 2 hours of a rebuild/modding it?
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MadsDausel 6/16/2022 12:56pm
6/16/2022 12:56pm
AH387 wrote:
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially...
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially a cause of some of these failures people are having. Just for clarification the rod went within 2 hours when it was stock? Or within 2 hours of a rebuild/modding it?
Twinair set up ánd I always use a vacuum cleaner if any dirt gets down... I rebuild the 35hours engine with new bearings , carrillo rod, piston and get the head ported.
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tek14
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tek14 6/16/2022 1:17pm
6/16/2022 1:17pm
First problem at 130 hours when clutch basket broke one finger.
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Richy
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Richy 6/16/2022 1:38pm
6/16/2022 1:38pm Edited Date/Time 6/16/2022 1:39pm
Being honest, not trying to be a dick, but getting dirt in there and using a vacuum cleaner to try and get it out isn't going to be a conclusive clean up effort, it is still opening yourself up to problems and if it's happening occasionally it could add up.

I'm not saying it's why the rod broke of course, just a word of caution.

I remember years ago I got a cam cover blasted and powder coated on a personal engine at a different place from usual, they didn't mask one little breather outlet and a small amount of media got in. There wasn't much and I blasted it out with an airline, the engine rattled it's tits off within a track day and there was a small but noticeable amount of 'gritty' stuff kicking amount and it just ground the bearings down enough to knock (automotive 'bearings', not ball bearings in a bearing race), which could have led to other issues had it planned out differently.
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The Shop

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MadsDausel 6/16/2022 1:54pm
6/16/2022 1:54pm
Richy wrote:
Being honest, not trying to be a dick, but getting dirt in there and using a vacuum cleaner to try and get it out isn't going...
Being honest, not trying to be a dick, but getting dirt in there and using a vacuum cleaner to try and get it out isn't going to be a conclusive clean up effort, it is still opening yourself up to problems and if it's happening occasionally it could add up.

I'm not saying it's why the rod broke of course, just a word of caution.

I remember years ago I got a cam cover blasted and powder coated on a personal engine at a different place from usual, they didn't mask one little breather outlet and a small amount of media got in. There wasn't much and I blasted it out with an airline, the engine rattled it's tits off within a track day and there was a small but noticeable amount of 'gritty' stuff kicking amount and it just ground the bearings down enough to knock (automotive 'bearings', not ball bearings in a bearing race), which could have led to other issues had it planned out differently.
I do know to clean and not getting dirt in the engine... I never have a bike in 10 years there have broke down,,, Last year I run a yz450f 60 hours with zero problems and when I replace the piston it look like new...
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lee82
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lee82 6/16/2022 2:11pm
6/16/2022 2:11pm
MadsDausel wrote:
How does your bike hold op? Mine broke a 2 hour conrod and I have talk to many with broken conrods I think a lot about...
How does your bike hold op?

Mine broke a 2 hour conrod and I have talk to many with broken conrods

I think a lot about whether to build it up and sell or try and race on it again.

The bike has ported head and higher compression, akrapovic pipe and vortex ecu.
High compression, hot intake air temps, aftermarket ecu (any idea of what timing or how lean you were running?), what about fuel? Detonation + high revs = boom.
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brocsdad
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brocsdad 6/16/2022 2:12pm
6/16/2022 2:12pm
Hello MadsDausel,

The 21 YZ 250F is very reliable until you start modifying the motor and raising compression. If you listen to the Jamie Ellis interview from Twisted Development he talks about the YZF being the most reliable motor until you throw mods in the motor. At that point it becomes one of the most expensive to modify.

Once you raise compression the stock rod is not safe. Everyone modding the motor installs a Carrillo Rod. You also mentioned installing a Vortex. The stock motor revs to 13,800 and on map 5 and 6 it allows the bike to rev to 14,300. The stock motor or valve train may fail under the additional rpms. That is why Twisted keeps the revs at 13,800 when mapping unless you have upgraded the rod and valve train.

Bolt on mods are fine like a pipe, air filter screen elimination kit and even the Vortex as long as you keep the stock rev limit or adjust to a setting that keeps the stock rev.

They are great bikes. I would install a Carrillo Rod and keep it.

Good Luck!
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MadsDausel 6/16/2022 2:27pm
6/16/2022 2:27pm
brocsdad wrote:
Hello MadsDausel, The 21 YZ 250F is very reliable until you start modifying the motor and raising compression. If you listen to the Jamie Ellis interview...
Hello MadsDausel,

The 21 YZ 250F is very reliable until you start modifying the motor and raising compression. If you listen to the Jamie Ellis interview from Twisted Development he talks about the YZF being the most reliable motor until you throw mods in the motor. At that point it becomes one of the most expensive to modify.

Once you raise compression the stock rod is not safe. Everyone modding the motor installs a Carrillo Rod. You also mentioned installing a Vortex. The stock motor revs to 13,800 and on map 5 and 6 it allows the bike to rev to 14,300. The stock motor or valve train may fail under the additional rpms. That is why Twisted keeps the revs at 13,800 when mapping unless you have upgraded the rod and valve train.

Bolt on mods are fine like a pipe, air filter screen elimination kit and even the Vortex as long as you keep the stock rev limit or adjust to a setting that keeps the stock rev.

They are great bikes. I would install a Carrillo Rod and keep it.

Good Luck!
Where can I listen to Jamie? Link?

It was my carrillo rod I broke... It turns "only" 14000 rpms in powermap 1...

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DA498
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DA498 6/16/2022 2:37pm
6/16/2022 2:37pm
Title should read, “21 YZ250F reliability after I modded it?”
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Lynch
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Lynch 6/17/2022 1:32pm
6/17/2022 1:32pm
AH387 wrote:
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially...
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially a cause of some of these failures people are having. Just for clarification the rod went within 2 hours when it was stock? Or within 2 hours of a rebuild/modding it?
MadsDausel wrote:
Twinair set up ánd I always use a vacuum cleaner if any dirt gets down... I rebuild the 35hours engine with new bearings , carrillo rod...
Twinair set up ánd I always use a vacuum cleaner if any dirt gets down... I rebuild the 35hours engine with new bearings , carrillo rod, piston and get the head ported.
Soo the stock engine lasted 35 hours no issues and the new carillo rod went out in 2 hours? I would talk to whoever put that togheter, sounds like he/she did something wrong along the way
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motoarmageddon 6/17/2022 4:33pm
6/17/2022 4:33pm
yamaha is not the most reliable. they were ok in 2009 when they didnt make any power. MXA wrote this one time and people are running with it. i would say all the bikes are similar in reliability. they all can break. the newer suzuki i haven heard of any engine probs actually but maybe thats because its down a little power at high rpm. spinning the engine high is how you get power, but then friction and therefore heat is higher as well.
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yak651
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yak651 6/17/2022 6:04pm
6/17/2022 6:04pm
AH387 wrote:
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially...
Mine's been fine. What intake/filter set-up are you using? Any dirt getting past the filter that you are aware of? I feel like that is potentially a cause of some of these failures people are having. Just for clarification the rod went within 2 hours when it was stock? Or within 2 hours of a rebuild/modding it?
MadsDausel wrote:
Twinair set up ánd I always use a vacuum cleaner if any dirt gets down... I rebuild the 35hours engine with new bearings , carrillo rod...
Twinair set up ánd I always use a vacuum cleaner if any dirt gets down... I rebuild the 35hours engine with new bearings , carrillo rod, piston and get the head ported.
Lynch wrote:
Soo the stock engine lasted 35 hours no issues and the new carillo rod went out in 2 hours? I would talk to whoever put that...
Soo the stock engine lasted 35 hours no issues and the new carillo rod went out in 2 hours? I would talk to whoever put that togheter, sounds like he/she did something wrong along the way
This right here….
Leeham
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Leeham 6/18/2022 1:17am
6/18/2022 1:17am
53 hours on mine. Rev the piss out of it. Twinair intake kit. Everything else stock. Put a new piston in at 50 hours. Looked immaculate. And I even lost oil at one point for a couple minutes. If it broke after you took the engine apart, then its not an OEM problem.
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Benjamin938 12/2/2022 10:00am
12/2/2022 10:00am
MadsDausel wrote:
How does your bike hold op? Mine broke a 2 hour conrod and I have talk to many with broken conrods I think a lot about...
How does your bike hold op?

Mine broke a 2 hour conrod and I have talk to many with broken conrods

I think a lot about whether to build it up and sell or try and race on it again.

The bike has ported head and higher compression, akrapovic pipe and vortex ecu.

Hello! I have a yzf250 2022 with a ported head, Vortex ecu, gytr camshafts, akrapovic full system and a twin air filter cage with a vhm air box and a vertex high compression piston. I have a mapp that runs 14,300 and my Engine builder Said that you must have other Valve springs if you have a higher rpm than original. Original Valve springs are maximum 13,800 rpm. I run pro circuit Valve springs. I have not have any problems other than it gets very hot and loses a little bit of coolant water and got a bigger left radiator to solve that problem. I run 102 octane fuel. 
 

sorry for my bad English 

CASH476
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CASH476 12/2/2022 10:33pm
12/2/2022 10:33pm
motoarmageddon wrote:
yamaha is not the most reliable. they were ok in 2009 when they didnt make any power. MXA wrote this one time and people are running...
yamaha is not the most reliable. they were ok in 2009 when they didnt make any power. MXA wrote this one time and people are running with it. i would say all the bikes are similar in reliability. they all can break. the newer suzuki i haven heard of any engine probs actually but maybe thats because its down a little power at high rpm. spinning the engine high is how you get power, but then friction and therefore heat is higher as well.

No one's reading MXA and running with what they said umless they're adding a tooth to the rear sprocket Laughing That's not why Yamaha had a reputation for reliability.

tek14
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tek14 12/2/2022 11:32pm
12/2/2022 11:32pm
MadsDausel wrote:
How does your bike hold op? Mine broke a 2 hour conrod and I have talk to many with broken conrods I think a lot about...
How does your bike hold op?

Mine broke a 2 hour conrod and I have talk to many with broken conrods

I think a lot about whether to build it up and sell or try and race on it again.

The bike has ported head and higher compression, akrapovic pipe and vortex ecu.
Benjamin938 wrote:
Hello! I have a yzf250 2022 with a ported head, Vortex ecu, gytr camshafts, akrapovic full system and a twin air filter cage with a vhm...

Hello! I have a yzf250 2022 with a ported head, Vortex ecu, gytr camshafts, akrapovic full system and a twin air filter cage with a vhm air box and a vertex high compression piston. I have a mapp that runs 14,300 and my Engine builder Said that you must have other Valve springs if you have a higher rpm than original. Original Valve springs are maximum 13,800 rpm. I run pro circuit Valve springs. I have not have any problems other than it gets very hot and loses a little bit of coolant water and got a bigger left radiator to solve that problem. I run 102 octane fuel. 
 

sorry for my bad English 

That sounds awesome and expensive bike. 

Pit Row

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Benjamin938 12/3/2022 12:02am
12/3/2022 12:02am
MadsDausel wrote:
How does your bike hold op? Mine broke a 2 hour conrod and I have talk to many with broken conrods I think a lot about...
How does your bike hold op?

Mine broke a 2 hour conrod and I have talk to many with broken conrods

I think a lot about whether to build it up and sell or try and race on it again.

The bike has ported head and higher compression, akrapovic pipe and vortex ecu.
Benjamin938 wrote:
Hello! I have a yzf250 2022 with a ported head, Vortex ecu, gytr camshafts, akrapovic full system and a twin air filter cage with a vhm...

Hello! I have a yzf250 2022 with a ported head, Vortex ecu, gytr camshafts, akrapovic full system and a twin air filter cage with a vhm air box and a vertex high compression piston. I have a mapp that runs 14,300 and my Engine builder Said that you must have other Valve springs if you have a higher rpm than original. Original Valve springs are maximum 13,800 rpm. I run pro circuit Valve springs. I have not have any problems other than it gets very hot and loses a little bit of coolant water and got a bigger left radiator to solve that problem. I run 102 octane fuel. 
 

sorry for my bad English 

tek14 wrote:

That sounds awesome and expensive bike. 

Yes it runs very well and was quite expensive but it was worth every penny.

MxAddic
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MxAddic 12/3/2022 6:32am
12/3/2022 6:32am

Most of the fast guys around here sign off on this model after a year or two due to reliability issues. Many die hard Yamaha guys ride the 2 stroke just for this reason.  It seems the more they increased the power in recent years the worse it got.

CG118
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CG118 12/3/2022 9:08am
12/3/2022 9:08am
MxAddic wrote:
Most of the fast guys around here sign off on this model after a year or two due to reliability issues. Many die hard Yamaha guys...

Most of the fast guys around here sign off on this model after a year or two due to reliability issues. Many die hard Yamaha guys ride the 2 stroke just for this reason.  It seems the more they increased the power in recent years the worse it got.

How many guys and what issues are they having?

Benjamin938 12/3/2022 11:51am
12/3/2022 11:51am
MxAddic wrote:
Most of the fast guys around here sign off on this model after a year or two due to reliability issues. Many die hard Yamaha guys...

Most of the fast guys around here sign off on this model after a year or two due to reliability issues. Many die hard Yamaha guys ride the 2 stroke just for this reason.  It seems the more they increased the power in recent years the worse it got.

I have never have a issue with mine and are quite faster than the average rider. I have a friend that rides the Emx250 and he blowd up 4 engines on 25 hours with only a get ecu on it he moved up to 450 now and that bike has worked just fine. I think its the 250 that have quality issues i have not heard many with problems on the 450.

MxAddic
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MxAddic 12/3/2022 12:59pm
12/3/2022 12:59pm
CG118 wrote:

How many guys and what issues are they having?

More than a few and mostly Engine related.

pyleracing617 2/23/2023 3:22am
2/23/2023 3:22am
brocsdad wrote:
Hello MadsDausel, The 21 YZ 250F is very reliable until you start modifying the motor and raising compression. If you listen to the Jamie Ellis interview...
Hello MadsDausel,

The 21 YZ 250F is very reliable until you start modifying the motor and raising compression. If you listen to the Jamie Ellis interview from Twisted Development he talks about the YZF being the most reliable motor until you throw mods in the motor. At that point it becomes one of the most expensive to modify.

Once you raise compression the stock rod is not safe. Everyone modding the motor installs a Carrillo Rod. You also mentioned installing a Vortex. The stock motor revs to 13,800 and on map 5 and 6 it allows the bike to rev to 14,300. The stock motor or valve train may fail under the additional rpms. That is why Twisted keeps the revs at 13,800 when mapping unless you have upgraded the rod and valve train.

Bolt on mods are fine like a pipe, air filter screen elimination kit and even the Vortex as long as you keep the stock rev limit or adjust to a setting that keeps the stock rev.

They are great bikes. I would install a Carrillo Rod and keep it.

Good Luck!

Working on modding, know people that do, but personally I’ve heard that any big modifications on any 250f become much less reliable and longevity decreases. Even car motors being built same thing building mass power creates a window for more failures. Also motors modified are more likely being ram harder. A lot of things to factor 

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