Yamaha 350

Panic_Rev
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Panic_Rev
Edited Date/Time 5/17/2016 8:50pm
I know this bike doesn't exist, but if you were going to create the closest thing possible to a KTM 350 with a Yamaha which would be a better choice? Bore a 250f and a few mods with reliability in mind, or tone down a 450?

I'm 165bs +30 currently on a 2015 yz250f mx track only. I've always had 250f's and enjoy them because I can ride aggressive without feeling like I'm going to kill myself. I'm sticking with Yamaha because of my relationship with the dealer.
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Sheriff245 5/17/2016 7:24am
5/17/2016 7:24am
The 450 can be tuned down with the Power Tuner to the point of being boring to ride, so I'd say this would be the easiest way to achieve 350-like power.
mx_563
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mx_563 5/17/2016 7:27am
5/17/2016 7:27am
The WR450 is probably choked up enough to feel like a 350. Slap a WR exhaust on a YZF and you are done. But why?
BobPA
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BobPA 5/17/2016 7:54am
5/17/2016 7:54am Edited Date/Time 5/17/2016 7:54am
You will never get the same power characteristics of the KTM 350 by detuning a 450. The 350 likes to be revved and ridden aggressively. A mellowed out 450 is just going to feel like a 450 that needs a rebuild. A hopped up 250 will be more comparable to the power delivery, but much less reliable.

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colintrax
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colintrax 5/17/2016 9:18am
5/17/2016 9:18am
BobPA wrote:
You will never get the same power characteristics of the KTM 350 by detuning a 450. The 350 likes to be revved and ridden aggressively. A...
You will never get the same power characteristics of the KTM 350 by detuning a 450. The 350 likes to be revved and ridden aggressively. A mellowed out 450 is just going to feel like a 450 that needs a rebuild. A hopped up 250 will be more comparable to the power delivery, but much less reliable.
This. If you want a Yamaha 350 you're best off to bore and stroke a 250.
But it won't be nearly as reliable as a stock KTM.
Derek Harris 5/17/2016 10:04am
5/17/2016 10:04am
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and nearly 25 lb ft of torque.

Once you gear it properly for the additional power by dropping two teeth on the rear - it's all you could want - with the handling of a 250f but the power needed to be competitive. The same power can be had with 250 mods - but the big bore is cheaper and produces easier to find low end HP.


With a full blown set up using our head, bigger valves, the big bore can easily go past 50 hp. And no need to go much past 270cc.

Of course - using a high quality rod is a must.

JWACK
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JWACK 5/17/2016 11:34am
5/17/2016 11:34am
Closest thing would be a Yz 250 twostroke.
resetjet
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resetjet 5/17/2016 11:38am
5/17/2016 11:38am
Ktms were based off the 250 for the reasons above.
HenryA
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HenryA 5/17/2016 12:11pm
5/17/2016 12:11pm
Why mod a bike when Yamaha already has a 350 engine? Cool

Phillip_Lamb
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Phillip_Lamb 5/17/2016 12:28pm
5/17/2016 12:28pm
Derek Harris wrote:
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and...
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and nearly 25 lb ft of torque.

Once you gear it properly for the additional power by dropping two teeth on the rear - it's all you could want - with the handling of a 250f but the power needed to be competitive. The same power can be had with 250 mods - but the big bore is cheaper and produces easier to find low end HP.


With a full blown set up using our head, bigger valves, the big bore can easily go past 50 hp. And no need to go much past 270cc.

Of course - using a high quality rod is a must.

i agree ^^^ best way is to do a full blown big bore, 450 your gonna have the weight and a chuggy motor.

the problem with the ktm 350 is the weight is too close to the 450 and its powerband too much like a 250 (ie not enough torque)
JWACK
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JWACK 5/17/2016 1:22pm
5/17/2016 1:22pm
Derek Harris wrote:
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and...
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and nearly 25 lb ft of torque.

Once you gear it properly for the additional power by dropping two teeth on the rear - it's all you could want - with the handling of a 250f but the power needed to be competitive. The same power can be had with 250 mods - but the big bore is cheaper and produces easier to find low end HP.


With a full blown set up using our head, bigger valves, the big bore can easily go past 50 hp. And no need to go much past 270cc.

Of course - using a high quality rod is a must.

Phillip_Lamb wrote:
i agree ^^^ best way is to do a full blown big bore, 450 your gonna have the weight and a chuggy motor. the problem with...
i agree ^^^ best way is to do a full blown big bore, 450 your gonna have the weight and a chuggy motor.

the problem with the ktm 350 is the weight is too close to the 450 and its powerband too much like a 250 (ie not enough torque)
My 16 350 weighs almost the same as a 250f and feels a ton lighter than a 450. So you are incorrect. Here is the proof. http://motocrossactionmag.com/news/ask-the-mxperts-what-does-the-2016-bikes-really-weigh
TailSoHard
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TailSoHard 5/17/2016 2:02pm
5/17/2016 2:02pm
I seemed to remember one of the magazines doing a CRF400 with a LA Sleeve kit on a CRF450. Can't remember whether they liked it or not, but i'm sure you could do the same thing with the Yamaha
Paw Paw 271
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Paw Paw 271 5/17/2016 2:13pm
5/17/2016 2:13pm Edited Date/Time 5/17/2016 2:14pm
Unless you can modify either a larger or smaller engine size that will turn 13,500rpm and live while having electric start, you might as well just get the KTM.

Paw Paw
fpandjic
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fpandjic 5/17/2016 2:19pm
5/17/2016 2:19pm
Derek Harris wrote:
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and...
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and nearly 25 lb ft of torque.

Once you gear it properly for the additional power by dropping two teeth on the rear - it's all you could want - with the handling of a 250f but the power needed to be competitive. The same power can be had with 250 mods - but the big bore is cheaper and produces easier to find low end HP.


With a full blown set up using our head, bigger valves, the big bore can easily go past 50 hp. And no need to go much past 270cc.

Of course - using a high quality rod is a must.

And what rod would you suggest for such mods?
RPM68
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RPM68 5/17/2016 2:51pm
5/17/2016 2:51pm
Derek Harris wrote:
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and...
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and nearly 25 lb ft of torque.

Once you gear it properly for the additional power by dropping two teeth on the rear - it's all you could want - with the handling of a 250f but the power needed to be competitive. The same power can be had with 250 mods - but the big bore is cheaper and produces easier to find low end HP.


With a full blown set up using our head, bigger valves, the big bore can easily go past 50 hp. And no need to go much past 270cc.

Of course - using a high quality rod is a must.

Is this San Antonio Derek Harris?
h&m_cycle
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h&m_cycle 5/17/2016 2:56pm
5/17/2016 2:56pm
HenryA wrote:
Why mod a bike when Yamaha already has a 350 engine? B) [IMG]https://p.vitalmx.com/photos/forums/2013/01/23/379686_476771415691629_902037723_n_197962.jpg[/IMG]
Why mod a bike when Yamaha already has a 350 engine? Cool

Who you kidding? That bike won't fart... It's not a fart box...

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TeamGreen
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TeamGreen 5/17/2016 3:10pm
5/17/2016 3:10pm Edited Date/Time 5/17/2016 3:11pm
Panic_Rev wrote:
I know this bike doesn't exist, but if you were going to create the closest thing possible to a KTM 350 with a Yamaha which would...
I know this bike doesn't exist, but if you were going to create the closest thing possible to a KTM 350 with a Yamaha which would be a better choice? Bore a 250f and a few mods with reliability in mind, or tone down a 450?

I'm 165bs +30 currently on a 2015 yz250f mx track only. I've always had 250f's and enjoy them because I can ride aggressive without feeling like I'm going to kill myself. I'm sticking with Yamaha because of my relationship with the dealer.
A slight bump in compression, remap for a good fuel like VPR or U4.4 and the motor will pull Waaaaaaay Harder and Waaaaay Earlier. You don't want rev-it like Barcia...or you'll need to build a better crank...

ALWAYS keep those valves adjusted & keep good valve springs and cam chains in it.
Underground 5/17/2016 3:55pm
5/17/2016 3:55pm
Just as Derek has said, I asked a good friend who's knows a lot about Honda's about doing to a CRF350-400 as I too have been through 250F's and wanted that bit more especially bottom, but not all that a 450 offers including the power, weight and reciprocating mass, but didn't want an unreliable and highly strung and high dollar mod 250. He told me that I would be better off staying with a 250 and that he could build me an engine that would have similar power to the 450 and be more reliable with less vibration than a big bore. Been trying to take him up on that offer but the wallet just wont let me at this point.
Or..... you could just sell the 250, buy a KTM 350 and just spend the money on getting the forks and front end working well, which will be a heap cheaper. Plenty of successful options out there and well documented here. See if you can get a ride on one. You'll find they're much thinner. They are reliable, handle well and I think just the ticket for us old farts who want Goldy Locks type power. But if you love your Yami, call Derek.
Phillip_Lamb
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Phillip_Lamb 5/17/2016 4:07pm
5/17/2016 4:07pm
Derek Harris wrote:
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and...
A customer built a 276cc yz250f using a GYTR head, our cams, a vortex, a CP piston, and a throttle body mod that made 48hp and nearly 25 lb ft of torque.

Once you gear it properly for the additional power by dropping two teeth on the rear - it's all you could want - with the handling of a 250f but the power needed to be competitive. The same power can be had with 250 mods - but the big bore is cheaper and produces easier to find low end HP.


With a full blown set up using our head, bigger valves, the big bore can easily go past 50 hp. And no need to go much past 270cc.

Of course - using a high quality rod is a must.

Phillip_Lamb wrote:
i agree ^^^ best way is to do a full blown big bore, 450 your gonna have the weight and a chuggy motor. the problem with...
i agree ^^^ best way is to do a full blown big bore, 450 your gonna have the weight and a chuggy motor.

the problem with the ktm 350 is the weight is too close to the 450 and its powerband too much like a 250 (ie not enough torque)
JWACK wrote:
My 16 350 weighs almost the same as a 250f and feels a ton lighter than a 450. So you are incorrect. Here is the proof...
My 16 350 weighs almost the same as a 250f and feels a ton lighter than a 450. So you are incorrect. Here is the proof. http://motocrossactionmag.com/news/ask-the-mxperts-what-does-the-2016-bikes-really-weigh
...ALMOST...the same. but not. you are right its not the same weight as a 450, however in its first few years its weight was up there, and compared to the ktm250f it is heavier. In fact most 250f's are 4-5 lbs lighter. Ironically if you go to 250fs before the efi's most of those are around 216 haha
Derek Harris 5/17/2016 6:15pm
5/17/2016 6:15pm
fpandjic wrote:
And what rod would you suggest for such mods?
Falicon or Carillo. Have used the CWI rod with good results too, although had one fail (they covered the cost of it and replaced it on that instance).

The OEM yamaha rods are a real disaster 14-15 - the 16's have been better.


One and the same RPM68
Panic_Rev
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Panic_Rev 5/17/2016 8:48pm
5/17/2016 8:48pm
Underground wrote:
Just as Derek has said, I asked a good friend who's knows a lot about Honda's about doing to a CRF350-400 as I too have been...
Just as Derek has said, I asked a good friend who's knows a lot about Honda's about doing to a CRF350-400 as I too have been through 250F's and wanted that bit more especially bottom, but not all that a 450 offers including the power, weight and reciprocating mass, but didn't want an unreliable and highly strung and high dollar mod 250. He told me that I would be better off staying with a 250 and that he could build me an engine that would have similar power to the 450 and be more reliable with less vibration than a big bore. Been trying to take him up on that offer but the wallet just wont let me at this point.
Or..... you could just sell the 250, buy a KTM 350 and just spend the money on getting the forks and front end working well, which will be a heap cheaper. Plenty of successful options out there and well documented here. See if you can get a ride on one. You'll find they're much thinner. They are reliable, handle well and I think just the ticket for us old farts who want Goldy Locks type power. But if you love your Yami, call Derek.
I've ridden the KTM 350. That is why I think it's the perfect motor for me. I'm stuck on Yamaha because my dealership is like family. I'm leaning towards tuning down a 450 when I decided to trade in the 250f. I only have 30 hours on it so upgrading at this point is just taking away from my daughters college fund. She should get a scholarship though right?
colintrax
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colintrax 5/17/2016 8:50pm
5/17/2016 8:50pm
Panic_Rev wrote:
I've ridden the KTM 350. That is why I think it's the perfect motor for me. I'm stuck on Yamaha because my dealership is like family...
I've ridden the KTM 350. That is why I think it's the perfect motor for me. I'm stuck on Yamaha because my dealership is like family. I'm leaning towards tuning down a 450 when I decided to trade in the 250f. I only have 30 hours on it so upgrading at this point is just taking away from my daughters college fund. She should get a scholarship though right?
You can still support that dealer by referring people there and buying everything but the bike.
I'm all for supporting a good dealership, but if the KTM 350 is what you really want. It's what you should get.

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