have you heard

[motometal]

Please if you get a two stroke to burn as clean as a 4 stroke mx can run it would be so close to running dangerously lean. 4 Stokes are just better designs they get gobs of lubrication two strokes don’t. So yes 4 stokes ARE cleaner bikes THEY DON’T BURN OIL plain and simple you cant get around the fact that a two stroke burns oil.

Also soon EFI will be coming to a 4 stroke near you lol, I would really love to see a two stroke burn as clean as a EFI 4 stroke bike, and to top it all off the 4 stoke will burn cleaner yet still get gobs of lube. And please no more fart comparisons, if your fart stinks more then your sons then that means your fart is more concentrated with higher levels of methane and sulfur SO YES YOUR FART WOULD BE DIRTIER lol.

As for the displacement rule being unfair I beg to differ, there is a reason why no one runs 2 strokes anymore and its because the 4 stroke is less tiring to ride and your able to go faster on it longer. So stop hating on 4 strokes its not there fault there a better design, of course a 4 stroke will be a bit faster on allot of tracks that’s what you get with a better design. 4 strokes HP numbers are dam near tide I think my 450 stock is about 48 HP well the two stroke 250’s are close or at the 48 HP mark, so again it just comes down to which bike is the better design.

There are so many things wrong with this that I don't know were to start, first off you need to do a bit of reading about the current state of outboard motors. And, keep in mind the same theories apply to our bikes. Two strokes can be very clean, and reliable. And evidently you haven't noticed that some of those 4 strokers burn some oil...in some cases, enough that they run low and toast the motors before the owner catches on. What do you think happened to THAT oil? I"m not saying they normally burn as much as a 2 stroke, but they do burn some.

So since when is a more complicated, more expensive engine, which inherently needs to be this way and be of larger displacement to compete, "superior"?

Ask a few fathers of kids racing in the "lites" class how jazzed they are about the new bikes, especially fathers that had kids who raced 125s back when they were popular...i'm sure they are thrilled with the doubling of costs to keep the bike going...

 

[Matt Fisher]

Please if you get a two stroke to burn as clean as a 4 stroke mx can run it would be so close to running dangerously lean. 4 Stokes are just better designs they get gobs of lubrication two strokes don’t. So yes 4 stokes ARE cleaner bikes THEY DON’T BURN OIL plain and simple you cant get around the fact that a two stroke burns oil.

Also soon EFI will be coming to a 4 stroke near you lol, I would really love to see a two stroke burn as clean as a EFI 4 stroke bike, and to top it all off the 4 stoke will burn cleaner yet still get gobs of lube. And please no more fart comparisons, if your fart stinks more then your sons then that means your fart is more concentrated with higher levels of methane and sulfur SO YES YOUR FART WOULD BE DIRTIER lol.

Pay attention here, it's not that difficult. Emissions are based on a pass or fail test, period. Your RM250 and your CRF450 both fail, period.

Try reading up on direct injection for 2 strokes. Then get back to me about how they can't ever pass emissions tests.

As for the displacement rule being unfair I beg to differ, there is a reason why no one runs 2 strokes anymore and its because the 4 stroke is less tiring to ride and your able to go faster on it longer. So stop hating on 4 strokes its not there fault there a better design, of course a 4 stroke will be a bit faster on allot of tracks that’s what you get with a better design. 4 strokes HP numbers are dam near tide I think my 450 stock is about 48 HP well the two stroke 250’s are close or at the 48 HP mark, so again it just comes down to which bike is the better design.

Once again, pay attention. 4 strokes are not a better design, they're a BIGGER design, um-kay. Change the rules to no longer favor the heavier, more expensive, more complicated, and louder 4-strokes, and that market will dry up like a puddle in hell.


At least you're been wrong on a consistent basis, starting with the statement that 2-strokes can't go 100 hours....

 

[Convert]

Out Of Hand

This has gone the way of madness already!! All this chatter about passing emissions testing is neither here nor there, a MX bike is a closed course bike, emissions mean nothing. Anyone here ever built a 350 chev?? or for better comparison say a SOHC toyota or honda automotive engine.....really not that difficult. So what's so hard about maintaining/building/replacing parts in a single piston engine with 4 valves? The argument that 4 strokes will break the bank if you need to work on them is BS, are they more expensive than a 2 stroke...yes....but let's be realistic if they were so painfully expensive they would not be so popular. It seems that the internet is doing great at spreading half truths and rumors from he said she said. Next...the issue about 4 strokes getting an advantage; argue all you want but the fact that a 2 stroke produces power on each stroke and the 4 stroke produces power on every other stroke can't be argued. So explain to me why you feel that it's unfair to almost double the cc in order to even out the playing field. The fact that a 4 stroke makes power over a broad rpm range is in fact better than the narrow range of a 2 stroke. 2 strokes are pretty damn cool when you hit that pipe and it rockets away, however, something can be said about cracking the throttle on a 4 stroke at any rpm and have it pull like gangbusters. If you like the 2 stroke you will most likely argue they are the better engine, if you like 4 the same applies. It's all about where technology is going and 4 strokes are where it's at. Deny it, cry about it, try to rationalize, believe everything you read on the net, do what you like...it's the truth.

 

[Dekester]

You are right. This thread got out of hand and it was due to crf 450 guy coming in here and and talking unintelligent TRASH.

First, he tries to slam me on a quote from another poster. If crf 450 guy had any brains, he would have seen that the same person later APOLOGIZED because he misinterpreted my post. I clarified with out any doubt whatsoever that I NEVER said 4 stroke riders were lazy. My original post was VERY clear about that in the first place. :coocoo: I even later further stated that I was not trying to make this thread into a 2/4 stroke thing and hoped it did not become one.

So crf 450 guy, either you are IGNORANT and can not understand basic english or you are LAZY and did not read the entire thread before posting. DISCLAIMER - FOR THE RECORD, YOU WERE CALLED LAZY IF YOU DID NOT READ THE POST AND NOT BECAUSE YOU RIDE A 4 STROKE! LOL!!!!

Then you say that a 450F handles better than a 250 2 stroke???? ARE YOU F'ING NUTS??? :coocoo: 450's are heavier and top heavy as well. You are the ONLY person I have EVER heard make that statement.

Just these two points alone tell me not to waste my time with you.

 

[Matt Fisher]

If you are going to act like an overbearing tool out here, at least get YOUR facts right.

Rich, the post I orignally responded to said:

I also get about a hundred hours on my top end on my CRF, TRY DOING THAT WITH A TWO STROKE HAHAHAHA.

I personally know several guys with way over a hundred hours on the top-ends of their 2-strokes, as I'm sure you do too. I never stated or insinuated that it was the best practice, any more so than it would be for a CRF.

Did I miss something? :whoa:

 

[Rich Rohrich]

Rich, the post I orignally responded to said:



I personally know several guys with way over a hundred hours on the top-ends of their 2-strokes, as I'm sure you do too. I never stated or insinuated that it was the best practice, any more so than it would be for a CRF.

Did I miss something? :whoa:

At 100 hours ANY modern race engine (2T or 4T) is clapped out. Just because some maintenance impaired goofball you know hasn't blown it to pieces doesn't make it a FACT that you can run it for 100 hours.

You are arguing with a guy who is clearly mis-informed about..... well..... everything. Posting nonsense pseudo-facts in response to him just drags you down to his level, and frankly makes my head hurt. ;)


Single compression ring four-strokes that are RACED hard start losing measurable power at around 8-10 hours. Depending on the port layout and the piston design two-strokes under the same conditions will do the same. Some of the 125s need rings at the 5 hour mark.

Just because people decide to live with the power loss doesn't mean it's not happening, and parts aren't worn out. People seem to think a part is not worn out until it exits the engine through some spectacular energetic disassembly event.

ALL RACE BIKES WEAR OUT. ALL HIGH SPECIFIC OUTPUT ENGINES RIDDEN BY RACERS WEAR OUT FAST.

Most riders can't even get their jetting within sniffing distance of correct, so expecting them to "feel" when their engines are worn out is laughable. Given how few hour meters I actually see in regular use, it's obvious to me that most riders have no idea how many hours they have on their engines. That is until they blow a hole in the cases, then they'll recite chapter and verse about their stellar maintenance practices, and quote you an EXACT number on hours even though they have never seen an hour meter let alone used one.

Two-stroke or four you can't change metallurgy and physics.

They put service intervals in the manual for a reason.

 

[Dekester]

Hey Convert,

I am going to make a couple of points on your last post. I am not trying to flame you, nor is my energy of that in my previous post.

"So explain to me why you feel that it's unfair to almost double the cc in order to even out the playing field. The fact that a 4 stroke makes power over a broad rpm range is in fact better than the narrow range of a 2 stroke."

The 250 2t and 450 4t competing together is NOT a level playing field. Your statement "The fact that a 4 stroke makes power over a broad rpm range is in fact better than the narrow range of a 2 stroke." answers your own question. Peak horsepower is similar, but with dramatically different power curves. Obviously an engine does not always run at peak power. Therefore the one that runs closer to peak power for the majority of the power curve would have an advantage.

An interesting and useful number that would really illustrate what I just said would be AVERAGE horsepower or AVERAGE torque over the entire curve.

That said, there would be some point where decreased 4 stroke cc's or increased 2 stroke cc's would offset each other fairly.

For the 125/250f class, maybe that fair balance would be increasing the 125 to say 144cc. I am just using 144 as a number for illustration. Then, the higher peak horsepower/torque of the 144 would offset the broader but lower peak horsepower/torque of the 250f. I think increasing the 125 is the better move here as traction issues would probably not come into play with the 144.

For the 250/450f class, I would think bringing the 450 down to say 350-400 would be ideal. Bringing the 4 stroke down in this class would probably reduce life threatening/changing injuries as well as keep tracks more universal to the smaller class. Additionally, an increase in 2 stroke cc's may make traction problems worse than they already are for the 2 stroke.

On another note, I feel you are downplaying the higher repair costs of MODERN 4 strokes. It is one thing to compare regular maintenance. It is completely a different beast when comparing catastrophic failure, which happens to 2 strokes and 4 strokes.

The difference is HUGE in this department and can not be debated and should not be downplayed. Replacing a top end on a 4 stroke that failed is huge. There are many more parts to buy and labor is higher as well. Not to mention the average person could do a top end on a 2 stroke. Not so on a modern 4 stroke. It is not very often where a 2 stroke is parted out due to a top end failure. I see it all the time on the 4 strokes.

 

[Matt Fisher]

At 100 hours ANY modern race engine (2T or 4T) is clapped out. Just because some maintenance impaired goofball you know hasn't blown it to pieces doesn't make it a FACT that you can run it for 100 hours.

You are arguing with a guy who is clearly mis-informed about..... well..... everything. Posting nonsense pseudo-facts in response to him just drags you down to his level, and frankly makes my head hurt. ;)


Single compression ring four-strokes that are RACED hard start losing measurable power at around 8-10 hours. Depending on the port layout and the piston design two-strokes under the same conditions will do the same. Some of the 125s need rings at the 5 hour mark.

Just because people decide to live with the power loss doesn't mean it's not happening, and parts aren't worn out. People seem to think a part is not worn out until it exits the engine through some spectacular energetic disassembly event.

ALL RACE BIKES WEAR OUT. ALL HIGH SPECIFIC OUTPUT ENGINES RIDDEN BY RACERS WEAR OUT FAST.

Most riders can't even get their jetting within sniffing distance of correct, so expecting them to "feel" when their engines are worn out is laughable. Given how few hour meters I actually see in regular use, it's obvious to me that most riders have no idea how many hours they have on their engines. That is until they blow a hole in the cases, then they'll recite chapter and verse about their stellar maintenance practices, and quote you an EXACT number on hours even though they have never seen an hour meter let alone used one.

Two-stroke or four you can't change metallurgy and physics.

They put service intervals in the manual for a reason.

You're right, of course.

I jumped right into an arguement that didn't need to be made. Sorry about the headache.



Going off your post, I do wonder- at what point does power start dropping off with an engine that's not ridden hard? Such as mild trail riding, or MX'd by a dweeb? And if a compression check yields the same good numbers at 50 hours that it did at 5, is there going to be a measurable power loss, or does that mean that the rings are good, but the piston skirt is ready to snap apart like a dry leaf?

 

[Rich Rohrich]

And if a compression check yields the same good numbers at 50 hours that it did at 5, is there going to be a measurable power loss, or does that mean that the rings are good, but the piston skirt is ready to snap apart like a dry leaf?

Compression checks on modern four-strokes are about as useful as handlebar tassles, and they aren't much better on two-strokes.

A leakdown test compared against a reference point is far more useful but not perfect.

Hours of run time is still the most reliable indicator for the average guy.

 

[Rich Rohrich]

On another note, I feel you are downplaying the higher repair costs of MODERN 4 strokes. It is one thing to compare regular maintenance. It is completely a different beast when comparing catastrophic failure, which happens to 2 strokes and 4 strokes.

The difference is HUGE in this department and can not be debated and should not be downplayed.

Given PROPER maintenance, the chance of a catostrophic failure for most Japanese MX four-strokes is incredibly small (RMZ/KXF 250s being the noticeable exception). PROPER maintenance is the key. Changing the oil and praying for good luck isn't enough.

The real problem comes from riders who are convinced they are much smarter than the engineers who developed the engines, so they invent their own justifications for ignoring the service intervals and run parts as long as they feel is appropriate based on some half-assed theory they came up with while sitting in traffic. When they inevitably destroy an engine they blame the "technology". Put a good design in an idiot's hands and trouble will eventually find him.

The only real difference between two and four stroke engines in this regard is most two-stroke engines give you a greater margin for acting like a dumbass.

When you maintain an engine properly a four-stroke will cost more over the life of the bike, but not the insane difference that twits on the internet would lead you to believe.

 

[Matt Fisher]

Compression checks on modern four-strokes are about as useful as handlebar tassles, and they aren't much better on two-strokes.

A leakdown test compared against a reference point is far more useful but not perfect.

Hours of run time is still the most reliable indicator for the average guy.

Understood and appreciated.

If a top rider needs rings at 10 hours, and the spec calls for rings at 30 hours (or whatever it is), then what kind of hours could/should a trail rider plan on changing out rings? I know it's a grey area, but I'm just trying to get a feel for the difference in wear. Not waiting until it's ready to grenade, but not leaving mileage on the table, so to speak.

Kinda like my dad- he gets 80,000 miles out of a set of tires, nearly twice the mileage the average joe would get out of the same set, and about 4 times what I'd be getting. If my dad were to change out his tires at 30,000 miles, the tire shop would likely ask him why, since he still has 3/4 of the original tread left.

 

[Rich Rohrich]

Understood and appreciated.

If a top rider needs rings at 10 hours, and the spec calls for rings at 30 hours (or whatever it is), then what kind of hours could/should a trail rider plan on changing out rings? I know it's a grey area, but I'm just trying to get a feel for the difference in wear. Not waiting until it's ready to grenade, but not leaving mileage on the table, so to speak.

I don't know, and frankly neither does anyone else unless you take the engine apart and carefully examine the parts over time there is no way to "accurately" answer that question. Of course that won't stop any number of clueless "experts" from telling you otherwise. :)

If you take a lot of engines apart, spend a lot of time examining parts and talking to the riders you can develop "reasonable" rules of thumb. That's what Eric Gorr does in his books. He takes the data from the engines we've pulled apart and does an excellent job of providing general service intervals for non-racers. Anyone racing on a regular basis would be well advised to pay attention to the factory intervals.

Kinda like my dad- he gets 80,000 miles out of a set of tires, nearly twice the mileage the average joe would get out of the same set, and about 4 times what I'd be getting. If my dad were to change out his tires at 30,000 miles, the tire shop would likely ask him why, since he still has 3/4 of the original tread left.

No disrespect meant to your Dad, but that tire at 80,000 miles has been environmentally hardened and in spite of showing tread, it won't work properly. It no longer has the characteristics it was designed with. It won't work properly in the rain, and won't carry the same side loads when it gets hot. Hardened tires don't show the same tread wear, but that doesn't mean they WORK. Lots of similarities here. ;)

 

[Convert]

Dekster,

No offense taken, I only want to touch on the comment about the 4 stroke being that much more expensive to fix and more difficult to work on. Seeing as I don't know your abilities when it comes to working on either the 2 or 4 so I can't appreciate your opinion when you imply that the average joe could not take care of a top end issue on a 4 stroke. I now have a few 2 stroke rebuilds (complete) and a RMZ 450 rebuild where a valve was dropped. As I said earlier it's no more difficult than working on an automotive engine (where I have quite a bit of experience) and as far as the cost....having done the RMZ450 for my maintenance impaired friend, and actually being able to order parts for him I know it's not that bad. Again....are they somewhat more pricey than a 2, yep, but I already admit that. Are they going to make everyone destitute....nope.
I hope I don't come across as a know it all because compared to a vast majority I don't know squat, however being that I do have experience in this area I figured I would pipe up.

Good Day

On a side note, I have about as much fun working on these things as I do riding them. Aside from suspension that is.

 

[CRF_450GUY514]

At 100 hours ANY modern race engine (2T or 4T) is clapped out. Just because some maintenance impaired goofball you know hasn't blown it to pieces doesn't make it a FACT that you can run it for 100 hours.

You are arguing with a guy who is clearly mis-informed about..... well..... everything. Posting nonsense pseudo-facts in response to him just drags you down to his level, and frankly makes my head hurt. ;)

I assure you I’m not a goofball mechanic nor am I miss informed about anything; I have only one hobby its bin that way since I was 9 years old and that hobby is moto. Never have I had a mechanic touch one of my bikes "Except for porting", since the age of 9 I started rebuilding my own two strokes I have owned/maintained almost every single bike there is, CR/RM/KX/YZ/YZF/CRF/SX/EXC. I rebuild at least 3 bikes a month I do all the work to mine and all my friends bikes at my local track.

So yes I have a vary good educated guess at how long my parts can safely run, and when it comes down to the two stroke vs 4 stroke I can honestly say that my 4 stroke is much more durable then my two stroke plain and simple I spend more time working on my two strokes. I agree with you a professionally raced single ring 4 strokes does start losing mad power at 8 hours but im talking about the average motocrosser, the average person or c class rider will not wear these things out in 8 hours. Also crank and crank bearing life in the 4 stroke is doubled and with after market pistons with wider skirts piston time in the CRF gets almost doubled as well, “that’s just based on my own experiences”.


So with that said I am not your average goofball that “thinks” he knows what he’s talking about, I have bin there and done it. My flawless condition 4 year old CRF and RM speak for them self’s I have NEVER had a catastrophic failure, I don’t leave parts in till there is serious power lose and I do take them apart and check clearances regularly.

 

[CRF_450GUY514]

Buy the way Rich I know you have no clue who I am but a couple years ago when I sent my CRF 450 head to Eric Gorr you ported it. I Talked with Eric and he said that you ported it, I must say you do Extremely good work that porting gob was impressive to say the least, just thought I would say thanks.

 

[Rich Rohrich]

I assure you I’m not a goofball mechanic nor am I miss informed about anything;

That's usually the first thing a misinformed goofball leads with by way of rebuttal.:rotfl:

Your posts speak VOLUMES about your skill set.

But don't let me keep you, I know you should be donning your foil hat and checking for black helicopters from the US government right now. :whoa:

 

[CRF_450GUY514]

That's usually the first thing a misinformed goofball leads with by way of rebuttal.:rotfl:

Your posts speak VOLUMES about your skill set.

But don't let me keep you, I know you should be donning your foil hat and checking for black helicopters from the US government right now. :whoa:

That’s cute Rich, speaking of the US government and black helicopters I am going to PM you something I think a smart person like yourself would love.

 

[oldguy]

That’s cute Rich, speaking of the US government and black helicopters I am going to PM you something I think a smart person like yourself would love.

Maybe a new theory or a rehash of the lubrication or lack of in the tectonic plates of Kalifornia :coocoo:

 

[oldguy]

:blah: :blah: :blah:

I edited this moron's conspiracy crap out of the post. RR
.

Yep you are right about you getting out.
Sorry to all the serious DRN members that have been following this thread but our local crack ball theorist has been going over the line in other posts and is now gone.

 

[justadirtbiker]

Wow how come you deleted that harmless post, I watched that video he was talking about DAM was it good.

Buy the way I'm new to the forums :cool:

 

[oldguy]

Wow how come you deleted that harmless post, I watched that video he was talking about DAM was it good.

Buy the way I'm new to the forums :cool:

His post had nothing to do with this subject and was deleted for language content origonlly and he couldn't let it go. Question answered and any more responces to the off topic suject here will be deleted. Now back to 2T vs 4T debating

 

[_JOE_]

His post had nothing to do with this subject and was deleted for language content origonlly and he couldn't let it go. Question answered and any more responces to the off topic suject here will be deleted. Now back to 2T vs 4T debating

Either way, I feel it's MUCH better to PREVENT catastrophic engine failure than to repair it afterward. The cost more than triples in most cases. I think I'll stick with routine maintenance.

 

[justadirtbiker]

Either way, I feel it's MUCH better to PREVENT catastrophic engine failure than to repair it afterward. The cost more than triples in most cases. I think I'll stick with routine maintenance.

I had a lower rod bearing fry solid last summer because I let it go to long, metal some how came off the bearings and totally F up my cylinder. I had to learn the hard way now I’m up on that stuff.

PS I really need to know how to bleed air from the shock oil could someone please help me?

 

[Rich Rohrich]

Either way, I feel it's MUCH better to PREVENT catastrophic engine failure than to repair it afterward. The cost more than triples in most cases. I think I'll stick with routine maintenance.

If more people would grasp those three simple, but very important sentences, there would be a lot less four-stroke angst in the world. :cool:

 

[AJ Waggoner]

The only real difference between two and four stroke engines in this regard is most two-stroke engines give you a greater margin for acting like a dumbass.

not to beleager a now age old argument,..

but thats exactly true, and frankly,
when it come to the average guy thats out there buying and riding a dirt bikes..

that cannot be downplayed?
its a big factor.
Face it , there are many that cant work on thier own 2 stroke,
so add the percieved complexity of the modern 4..
mixed with the fact that this *averge joe* doesnt do proper maintence on any bike he owns..

you have a recipe for him getting "by" much better with the bike that allows him to do so.

this isnt rocket science,,
nor are most dirt bike buyers mechanics.

I would say the avergae joe reading this forum , or any avid reader of any dirt bike forum,.,
is likely able to work on his bike,or has a buddy that can etc,,
, but he probably does not represent the averge joe in public buying these bikes.

we can squable over the advantages or disadvantegs of each bike,..

but to the average consumer buying them..
it does ultimately make a big difference..

the amount of service work on dirt bikes has certainly increased at local shops..
so has the amount of catistrophic engine failures.
sales went up (and back down) as well, accounting for some of that ,
but not in the percentages that the service work did.

if these average joes where buying the older style XR line up.. you think that would be true? or the 2 strokes they always had..??
the grapgh would be directly relatve of sales.. as it generally always has been?

in my thoughts -
If average guy buying it perceives it to be hardfer to work on,.. his perception becomes the reality of the market place.

wether his perception is accurate or not,
ultimately doesnt matter.?
it will not change the average trade in value of his new 4 stroke,,
(as MOST other average joes perception is the same)
nor does it change how often he brings it into the shop for minor service work or for castastrphic failiures.
in fact, it makes and establidshes those very things..
because as "average joe" , his perception makes the market reality ..

despite the service maintence intervals, or relalibity of either machine when maintained properly?


just a few thoughts....