DT125R ARCHIVE

just because youve ''beat'' other dt's doesnt mean your bike has benefitted from the locking of the pv LOL!


if you read up and do your research, the powervalve has no loss in power, it has no losses AT ALL, it only gains you some bottom end power. fact. google it.


as long as the powervalve is set up CORRECTLY, cables adjusted right, powervalve is clean and not gummed up, a PV bike would be a couple seconds quicker than a locked open bike.


there is no arguing and discussion, its fact, yamaha spent years developing the technology, they wouldnt spend money putting it into production if the bikes would be faster simply by leavin them locked open would they? they wouldnt be fitted to race bikes if they made them slower? im sure yamaha know a bit more than all of us.


im not gonna reply again now lol cause i dont wanna cause a massive debate, but the facts are there and its pretty much common sense, i can see why you thought it made you faster because the instant feel of the bike will make you think ''woah the powerbands kicking in hard now''

Servo or pinned open wont make any difference to the top speed, the servo doesn't give extra power it just closes the exhaust port to give the engine a bit more low end torque.

The late 80,s and early 90,s UK DTR,s and TZR,s with no servo fitted were only like that as they had to be restricted for our UK learner laws and the easiest and cheapest way for Yamaha to do it was to remove the servo and pin the YPVS closed with a blank, then weld a small tube into the exhaust manifold. They could have fitted the servo and left the right cable loose so it would not open, But then they could not charge a fortune for a servo if you had a full licence as back then u had to show them it before they would even sell you a sevo for a DTR or TZR125. The early bikes made full power with the YPVS rotated and pinned fully open with the exhaust manifold restriction removed. Early 89 90 91 models went really well like this and I preferred them without the servo but its a matter of each to everyone's own isn't it.

Of the later bikes, only the RE/X,s seem to pull as good as the old ones with a pinned open YPVS.

When Maccas bike had a 125 engine in it, it had an 89 loom cdi flywheel etc fitted and the YPVS pinned open when it was virtually brand new by me as it had a 3RM-10 cdi from new and with everything u can think of done to derestrict it, it just would not go.

Just glanced through but seriously... running servo is obviously going to be better it's obvious when you understand how it works.

You will have the exact same power at 7/8k + revs but below that the servo will have the upper hand. It will feel 'quicker' because the difference on a pinned setup between the high and low revs is a lot more. But in reality all you've done is make it slower at the bottom end so the top end feels quicker.

That's fact really

Heard people say 'it's faster at the top end' but whether you pin or or get a servo, after this amount they will be running at the exact same valve position so that's quite literally impossible.



Same concept in cars. One that is naturally aspirated at 200bhp will feel slower than one that is boosted to 200bhp. Purely just because the power isn't gradual, when in fact the boosted setup will be slower when gone through the entire rev range.


Only reason a pinned setup could ever be quicker is if the servo wasn't working correctly and wasn't opening the powervalve fully.

 

Edit: Didn't go on page 2 to see it already said haha

-- Edited by Harry on Tuesday 19th of March 2013 09:13:52 PM

hes clearly had an ego boost from the powerband being more prominent and now thinks hes faster without a servo just because it feels faster at around 6k rpm kicking in.


its like when people argue that there mini moto or there pitbike is faster than a DT. clearly isnt but they will argue til they are blue in the face.

 

 

edit: if it only revved to 9k, you either had the powervalve cables adjusted wrong, the powervalve was gummed and siezed up (needs cleaning regular) OR you had it spun 180 degrees out so it was closing the valve instead of opening it which is a common error

-- Edited by tunertom on Wednesday 20th of March 2013 12:10:41 AM

Update !!!!!!!!!!!!!

Postman brought all my parts at once and she's all done after good few hours in the shed :D

millsy wrote:

---

Update !!!!!!!!!!!!!

Postman brought all my parts at once and she's all done after good few hours in the shed :D

---

 make sure u take it easy for the 1st 500 mile m8 and make more use of the gear box and use a mineral 2t oil till the 500 mile is up 

whats that with your red power bands?

macca, dont mean to be rude, but you are mistaken, its proven that itll be quicker at accelerating with the servo, PROVEN.


so whether you think that ''my dt's faster than all yours'' or not, servos help with low end grunt and have the same top end power as a pinned bike.


98% of people on here will agree with me

yeah but fam my dt that runs a yz engine like with red powerbands will kill your smr init

DT200R MACCA wrote:

---

pinned is quicker than a servo av had and been on loads of dts and every 1 of them thats had a 3 or 5 wire  servo has been like a slug u dont get any more top end off pinning the valve but its a lot quicker throw the box

---

 

Mate, no offense but if knew how it worked you would realise how wrong you are.

 

But this same story goes on with powerband colours, electric turbo chargers, and fuel magnets so best to just sit back and watch people being happy with whatever they have.