4 stroke question!

bigrigger241
Edited Date/Time 3/17/2012 9:22am
I just wanted to ask everyone what the future holds for 4 strokes in motocross. I'm sitting here thinking about our sport and I know the 250f and 450f bikes are all pretty dominate but what about the 80's and 65's. Yes Honda has the 150 but do you guys think these 4 strokes will progress threw the mini bike class and maybe take over as they are in the big bikes.
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newmann
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newmann 3/17/2012 7:11am
3/17/2012 7:11am
Honda is busy geasing palms in order to establish the 150's dominace in the mini ranks.
SwapperMX
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SwapperMX 3/17/2012 7:23am
3/17/2012 7:23am
I can tell you for a fact that Yamaha had a finished alloy frame prototype YZ150F that it wanted to set loose on the 85cc class, but didnt due to a variety of reasons.
bigrigger241 3/17/2012 7:26am
3/17/2012 7:26am
I think it would be hilarious if a bunch of mini riders lined up just banging the rev limiter with there dad pumping them up ✊
roughneck
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roughneck 3/17/2012 7:45am
3/17/2012 7:45am
We almost went that way when my son was on 85s..But the Honda was the only one and kind of a turd unless you pumped it up..Another thing that stopped us..was at that time you could only run it in a supermini class..

The reason we were thinking of going to the 150 was because it was bullet proof...While we were loading up the blown up 2-stroke once again...the 150 never missed a race.

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Flip109
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Flip109 3/17/2012 7:51am
3/17/2012 7:51am
roughneck wrote:
We almost went that way when my son was on 85s..But the Honda was the only one and kind of a turd unless you pumped it...
We almost went that way when my son was on 85s..But the Honda was the only one and kind of a turd unless you pumped it up..Another thing that stopped us..was at that time you could only run it in a supermini class..

The reason we were thinking of going to the 150 was because it was bullet proof...While we were loading up the blown up 2-stroke once again...the 150 never missed a race.
Dang my son is almost ready for an 85 and I figured it would e the opposite. I just figured the 150 was a little ticking time bomb considering the 250f's are so prone to coming apart. How often did you do top ends valves etc. on the 150?
roughneck
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roughneck 3/17/2012 7:55am
3/17/2012 7:55am Edited Date/Time 3/17/2012 7:56am
roughneck wrote:
We almost went that way when my son was on 85s..But the Honda was the only one and kind of a turd unless you pumped it...
We almost went that way when my son was on 85s..But the Honda was the only one and kind of a turd unless you pumped it up..Another thing that stopped us..was at that time you could only run it in a supermini class..

The reason we were thinking of going to the 150 was because it was bullet proof...While we were loading up the blown up 2-stroke once again...the 150 never missed a race.
Flip109 wrote:
Dang my son is almost ready for an 85 and I figured it would e the opposite. I just figured the 150 was a little ticking...
Dang my son is almost ready for an 85 and I figured it would e the opposite. I just figured the 150 was a little ticking time bomb considering the 250f's are so prone to coming apart. How often did you do top ends valves etc. on the 150?
No iam saying we didnt go to the 150 because it was kinda of a turd..We had friends that had them and they just always run..My son didnt like the feel of it after jumping off his yz 85..the 150 felt heavy and slugish..

Hes on 250f's now

I never ever seen a problem happen to a crf150r
SteveS
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SteveS 3/17/2012 8:00am
3/17/2012 8:00am
I often wonder about people who had blown up 85's all the time. We ran 85's and superminis from 2001-2006 (Yamahas) and never had a motor ever fail, never had a dnf due to the motor. Had some trouble with certain brands of clutch not working right.

It may have been because we spent our money wisely on mods (RPM for the supermini motor and Pro Circuit for the 85 Mod motor) and didn't screw around with local guys who "know how to hop up" motors. But all I can say is I was only spending money on tires, oil, air filters and filter oil, and clutches.

The 250F has been another adventure altogether, even though my son pretty much dropped out of racing once we got that.
Flip109
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Flip109 3/17/2012 8:02am
3/17/2012 8:02am
Oh ok gotcha. Yea I really never plan on putting him on four strokes until he's old enough to buy and maintain his own. If he wants one. We really just ride for fun anyway. The only four strokes I will ever buy are 450's. Just because you never really rev them out and they actually last.
Bandito121 3/17/2012 8:23am
3/17/2012 8:23am Edited Date/Time 3/17/2012 8:31am
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on them is 1/4 of what it was on a 2 stroke. Now days, if you have an engine failure on a 4 stroke it's probably your fault. If your idea of maintenance is ride it until it blows up and then fix it, then stay with a two.
roughneck
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roughneck 3/17/2012 8:35am
3/17/2012 8:35am
I agree with ya 100% we also have never had a problem with the 4-strokes..as far as fun to ride..My son loves his 4-stroke but..the 2-stroke is way funner to ride..In fact..Iam going to get him another 2-stroke..looking for a 05 or newer yz125..Just want to trick one out...Kid like to race them..I like to tinker with them..
insane one
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insane one 3/17/2012 8:46am
3/17/2012 8:46am
I just have to say; that as far as the ruling goes in the 85cc class.. First of all the AMA bent the rules for Yamaha to be able to race the YZ400F. Its only a matter of time b4 the other manufactures follow suit in the 150cc four stroke. So with that being said. The AMA will also follow suit. Just like they did with the open class. When they dropped it do to Yamaha and Suzuki no longer building a 500cc two stroke.. I bet as soon as Yamaha, Suzuki and Kawasaki build and sell the 150cc four stroke. The AMA Will give in! As far as blown engines, the same can be said for any bike. But, no matter what anyone says the four stroke will never be able to take the wide open abuse like a two stroke!! You start floating the valves on the four stroke eventually you will be doing a top end job.
PaleBlue
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PaleBlue 3/17/2012 8:46am
3/17/2012 8:46am
Bandito121 wrote:
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on...
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on them is 1/4 of what it was on a 2 stroke. Now days, if you have an engine failure on a 4 stroke it's probably your fault. If your idea of maintenance is ride it until it blows up and then fix it, then stay with a two.
Four strokes have become even more of a liability with the advent of fuel injection. On top of the normal and disasterous stretched valve problems, we now have temperature sensor failures which cause the ECU to 'lean out' the fuel mix to an engine it thinks is running cool, thus overheating the motor and warping the heads. Both of my friends 2010 Suzuki 250Fs fell foul of this - also happens to KTM's to my certain knowledge. Then of course the is also the TPS sensor problems. Yep, god bless four strokes.
roughneck
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roughneck 3/17/2012 9:04am
3/17/2012 9:04am
Bandito121 wrote:
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on...
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on them is 1/4 of what it was on a 2 stroke. Now days, if you have an engine failure on a 4 stroke it's probably your fault. If your idea of maintenance is ride it until it blows up and then fix it, then stay with a two.
PaleBlue wrote:
Four strokes have become even more of a liability with the advent of fuel injection. On top of the normal and disasterous stretched valve problems, we...
Four strokes have become even more of a liability with the advent of fuel injection. On top of the normal and disasterous stretched valve problems, we now have temperature sensor failures which cause the ECU to 'lean out' the fuel mix to an engine it thinks is running cool, thus overheating the motor and warping the heads. Both of my friends 2010 Suzuki 250Fs fell foul of this - also happens to KTM's to my certain knowledge. Then of course the is also the TPS sensor problems. Yep, god bless four strokes.
You wouldnt have that problem if you were riding a Honda...lol..jk
SteveS
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SteveS 3/17/2012 9:13am
3/17/2012 9:13am
insane one wrote:
I just have to say; that as far as the ruling goes in the 85cc class.. First of all the AMA bent the rules for Yamaha...
I just have to say; that as far as the ruling goes in the 85cc class.. First of all the AMA bent the rules for Yamaha to be able to race the YZ400F. Its only a matter of time b4 the other manufactures follow suit in the 150cc four stroke. So with that being said. The AMA will also follow suit. Just like they did with the open class. When they dropped it do to Yamaha and Suzuki no longer building a 500cc two stroke.. I bet as soon as Yamaha, Suzuki and Kawasaki build and sell the 150cc four stroke. The AMA Will give in! As far as blown engines, the same can be said for any bike. But, no matter what anyone says the four stroke will never be able to take the wide open abuse like a two stroke!! You start floating the valves on the four stroke eventually you will be doing a top end job.
They've let the 150 into the 85 class this year already. It's called Mini Senior now.
SteveS
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SteveS 3/17/2012 9:16am
3/17/2012 9:16am
Bandito121 wrote:
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on...
Thank god for the 4 strokes. We are on our 6th 4 stroke and never have had an engine failure and my maintenance I do on them is 1/4 of what it was on a 2 stroke. Now days, if you have an engine failure on a 4 stroke it's probably your fault. If your idea of maintenance is ride it until it blows up and then fix it, then stay with a two.
Well if you buy a new bike every year you aren't going to run into the 4 stroke's biggest problem.....the people who buy your used ones will!

We do the same amount of maintenance on the 4 stroke that we did on the 2 stroke--with the addition of having to change an oil filter, plus having to check the valve clearances.

It's when you experience valve wear that the 4 stroke gets expensive---or when it grenades as happened with ours.
PaleBlue
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PaleBlue 3/17/2012 9:22am
3/17/2012 9:22am
150s have been racing against 85s in the UK for several years now. Most of the fastest boys are still on 2Ts (KTMs). But some do choose the Honda. But it's the slower and less skilled riders that particularly like the 4T Honda, as they get an immediate increase in speed because they are easier to ride. They don't really progress though and the riders that persevere with the 2Ts ultimately tend to be the faster riders.

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