fuel injected TM 2t

[burn1986]

Okay, not to down the 05-07 CRs, everyone's right, they should have finished the job. Rather than say the Honda Powervalve was a bad design, i will say that it was an unfinished design. I don't see why they couldn't make a powervalve that doesn't require you to adjust he wires, which loosen. Simpler is better IMO, sans the 01 CRs.

[SubTexel]

Okay, not to down the 05-07 CRs, everyone's right, they should have finished the job. Rather than say the Honda Powervalve was a bad design, i will say that it was an unfinished design. I don't see why they couldn't make a powervalve that doesn't require you to adjust he wires, which loosen. Simpler is better IMO, sans the 01 CRs.

They had the right idea, it just didn't fully pan out (especially since Honda pulled the Sr. engineers from the 2 stroke side and threw them into the 4 stroke program). Same goes with their attempt @ the case reed. I'm all for simplicity, however you can't say Honda was trying to bring some innovations to the 2 stroke market. Too bad they just dropped it.

[KXwestYZ]

What ever gets the 2-stroke back in business here is all I want. Whatever the enviros happy, I guess. Hopefully TM won't screw up their bikes like Honda did to the 05-07 2-strokes. I'm sure they won't, but...

Honda didn't screw up the 05-07s, they improved them over the 02-04 (and by quite a bit)... But Honda had already planned for the 2 strokes to be obsolete with the introduction of their 450 in 2002. They left a lot on the table, so sad they didn't finish as there was (and is) so much potential in their case reed motors.

Maybe TM will introduce a programmable valve so you can tune it like you do on the KTMs with the springs on their mechanical PV... That'd be nice. Throw that in with EFI or DI and it'd be beyond sweet.

Sorry but i had to reply to you on this I had a KTM 250sx with variable power valve springs but all this talk of 'tuning them' is a load of rubbish all that happens is the stronger the spring the more you disable and weaken the power valve, you dont get anything extra from doing this in different parts of the rev spectrum - if you choose the strong spring it just doesnt let the power valve come in - until its to late for it to give any extra sort of power you'd even notice, its basically for riders who cant handle a power valve - great for novices but of no use for anyone used to riding a decent 2 stroke.

I disagree, it's a valuable option for tuning the bikes for different tracks (I run the red spring a lot on the 4 stroke groomed tracks). (I have a 2010 250SX btw)...

[SubTexel]

What ever gets the 2-stroke back in business here is all I want. Whatever the enviros happy, I guess. Hopefully TM won't screw up their bikes like Honda did to the 05-07 2-strokes. I'm sure they won't, but...

Honda didn't screw up the 05-07s, they improved them over the 02-04 (and by quite a bit)... But Honda had already planned for the 2 strokes to be obsolete with the introduction of their 450 in 2002. They left a lot on the table, so sad they didn't finish as there was (and is) so much potential in their case reed motors.

Maybe TM will introduce a programmable valve so you can tune it like you do on the KTMs with the springs on their mechanical PV... That'd be nice. Throw that in with EFI or DI and it'd be beyond sweet.

Sorry but i had to reply to you on this I had a KTM 250sx with variable power valve springs but all this talk of 'tuning them' is a load of rubbish all that happens is the stronger the spring the more you disable and weaken the power valve, you dont get anything extra from doing this in different parts of the rev spectrum - if you choose the strong spring it just doesnt let the power valve come in - until its to late for it to give any extra sort of power you'd even notice, its basically for riders who cant handle a power valve - great for novices but of no use for anyone used to riding a decent 2 stroke.

I disagree, it's a valuable option for tuning the bikes for different tracks (I run the red spring a lot on the 4 stroke groomed tracks). (I have a 2010 250SX btw)...

Which is my point, on slick tracks the differing springs would allow you to take some hit out so you aren't out there spinning. etc... throttle control helps a lot, but having something mellow it out / make the hit harder for different terrains and tracks helps.

So, adjustable power valves are are great thing. (electronic or otherwise).

[TMKIWI]

Being able to adjust when the power valve opens has benefits in very slippery conditions.
It does not though effect peak power at all, unless you stop the power valve opening all together.
Most of the european enduro bikes now come with a ignition switch to switch between two pre programed ignition maps.

[offroader]

Interesting thing is that the wec guys are known to wire there pv full open to eliminate the hit completey.

[TMKIWI]

Interesting thing is that the wec guys are known to wire there pv full open to eliminate the hit completey.

That would work, but it would completely stuff up your low end power.

[offroader]

They do not rid on the bottom of the torque much.

[evo550]

Interesting thing is that the wec guys are known to wire there pv full open to eliminate the hit completey.

The motor would still have a "hit", they would just lose bottom end power.
The power valve basically give the motor two exhaust port heights, one for good low end power, and one for good top end power. The speed at which it opens can effect the transition from bottom to top ie. mid range or "hit"
Most pre powervalve bikes had a bigger "hit" than todays machines because they had very little bottom end power.

[SachsGS]

When I bought my first Maico 500 I didn't know it at the time but the guillotine style powervalve was broken and had fallen down, retarding the exhaust port timing. The bike was smoother then a fourstroke and was a torque monster.

When I repaired the powervalve, what a difference! The bike still had the same smooth bottom end but when that powervalve opened the power that 500 made! It was about then that my CR500 buddies stopped trying to drag  race me.

[KXwestYZ]

What ever gets the 2-stroke back in business here is all I want. Whatever the enviros happy, I guess. Hopefully TM won't screw up their bikes like Honda did to the 05-07 2-strokes. I'm sure they won't, but...

Honda didn't screw up the 05-07s, they improved them over the 02-04 (and by quite a bit)... But Honda had already planned for the 2 strokes to be obsolete with the introduction of their 450 in 2002. They left a lot on the table, so sad they didn't finish as there was (and is) so much potential in their case reed motors.

Maybe TM will introduce a programmable valve so you can tune it like you do on the KTMs with the springs on their mechanical PV... That'd be nice. Throw that in with EFI or DI and it'd be beyond sweet.

Sorry but i had to reply to you on this I had a KTM 250sx with variable power valve springs but all this talk of 'tuning them' is a load of rubbish all that happens is the stronger the spring the more you disable and weaken the power valve, you dont get anything extra from doing this in different parts of the rev spectrum - if you choose the strong spring it just doesnt let the power valve come in - until its to late for it to give any extra sort of power you'd even notice, its basically for riders who cant handle a power valve - great for novices but of no use for anyone used to riding a decent 2 stroke.

I disagree, it's a valuable option for tuning the bikes for different tracks (I run the red spring a lot on the 4 stroke groomed tracks). (I have a 2010 250SX btw)...

Which is my point, on slick tracks the differing springs would allow you to take some hit out so you aren't out there spinning. etc... throttle control helps a lot, but having something mellow it out / make the hit harder for different terrains and tracks helps.

So, adjustable power valves are are great thing. (electronic or otherwise).

yeah ok cool

[offroader]

Interesting thing is that the wec guys are known to wire there pv full open to eliminate the hit completey.

The motor would still have a "hit", they would just lose bottom end power.
The power valve basically give the motor two exhaust port heights, one for good low end power, and one for good top end power. The speed at which it opens can effect the transition from bottom to top ie. mid range or "hit"
Most pre powervalve bikes had a bigger "hit" than todays machines because they had very little bottom end power.

Hence why they dosconnect as they do not want that transitional hit.They tend to ride wfo most of the time and want massive power now.

[ford832]

Running a servo controlled pv seems to me like fixing something that isn't broke.On the other hand,my '85 RZ had one and it worked ok,just not a revolution.
As far as FI goes,unlike the rest of you old(and young),set in your ways fossils -I'm all for it-even if not a full DI system.Ski-doo's SDI (semi direct) is a great system too.Baby steps are better than none and sometimes allow for better development in the long run.

[JETZcorp]

Agreed, provided that some innovation will make the bike better (and if it gets 0.5% more performance but increases maintenance by 50% then it's not better in my opinion) then by all means it should be employed.  I'm not saying that fuel injection is going to make the bike more difficult to maintain, but IF it did, then the rewards in performance should be greater than the costs in time and money that would go into keeping the thing up and running, and that goes for every innovation, from aluminum frames, to round wheels.  Sometimes the cost-benefit analysis is a no-brainer.

[cmiller493]

Well said Jetz. If they create a fuel injection system that requires a lot of maintenance, that is just defeating the whole idea of our "cheap and easy to maintain" 2 strokes.