DT125R ARCHIVE

Luke · Guru

Setting PV Back Up After Year (+) With It Pinned?

Calum122 · Guru

Wouldn't hurt. The powervalve runs through a cleaning cycle when you turn the ignition, yours hasn't for a while. Ten minute job to just take it out and give it a good clean.

Luke · Guru

How do I take it out? Will I need to remove the topend? Thanks for the reply.

Will it hurt much to skip cleaning it? Also if I did clean it what substance should I use, petrol?

Calum122 · Guru

No you don't need to remove the top end.

Cleaning it in situe isn't advised as you need a degreasent and naturally you'll degrease the bore at the same time.

Take both sides of the powervalve end caps off. on the right hand side of the cylinder you'll see that there is a place for a 4mm allen key to go in. Undo that bolt and then the two halves can be separated. This is pretty annoying to do and I've found the best way is to remove the exhaust and use a screwdriver to separate the two.

On the pulley side you'll need to slacken off the nuts and remove the pulley housing. then the other half of the powervalve can be removed.

It's not a hard job, just removing it can be time consuming.

But kill two birds one stone, have a ganders up the bore make sure it's all legit. And clean it all up with some hot water and soap.

Luke · Guru

Cheers, I'll definitely do that then.

And washing up liquid will suffice?

FunkeyMunkeyDavid · Guru

wd40 and a stiff toothbrush works wonders for removing carbon too

Calum122 · Guru

Yeah you do want a degreasent, but that said elbow grease will suffice

Luke · Guru

Anyone got any pictures of the PV in the exhaust port? I had a quick gander but couldn't see where to stick the flat head to separate it?

Managed to lose my little ratchet as well so I'll need to get my hands on another.

Luke · Guru

I can't see anything to separate it in the exhaust port??

Calum122 · Guru

There won't be, a thin flat blade or a stanley down the seam will allow it to split and get you more leverage.

Luke · Guru

Oh right. Going to get a proper look at it later. Cheers for the advice.

Luke · Guru

Anyone de-carbonising their PV use carb cleaner. It's so much easier.

Luke · Guru

The cap on the right side has snapped just near the thread. Hoping I can get it welded up by an engineer. My dad's taken it to a engineer as I write this.

Calum122 · Guru

Yeah a degreasent would be ideal. It's also worth while polishing the powervalve like I showed in the tutorial to prevent carbon build up next time around.

What part did you Snap? It might just be easier to get another end cap if you've snapped that. A welded one would look gash.

Luke · Guru

The little cap thing that goes on the right of the barrel where the expansion pipe goes over. Should have put oil on it and then pushed it in. Dad used a hammer on it not thinking and snapped it just behind the hole to tighten it on to the barrel. Been scouring eBay for one, looks near impossible to find a used one. And it'd be extortionate to buy a new one from Yamaha. The exhaust covers it up so it isn't too much of a concern.

Where can I find that tutorial? What polish did you use?

Calum122 · Guru

Yeah I guarantee you Deetee has one spare mate. I did have loads but have sold them all. If I find another one I'll let you know. You don't want to ride around without on. Bike will sound GASH!

Just some autoglym metal polish. Just search skim head.

Luke · Guru

I've got it sorted now. Engineer sorted it out couldn't tell it was welded from the outside. I have some pictures of it. I'll post them tomorrow as I'm on my phone.

FunkeyMunkeyDavid · Guru

happy days! can be a sod to find now,and how easy to break?

have bought a few dt's that have a massive washer to bodge the cap in place bleh

Luke · Guru

It's a lot easier to fit if you coat it in 2 stroke.

And I've had the chance to ride the bike today. The PV is all set up to what it should be on the Haynes manual. It seems to be restrictive at the end of the rev range for some reason. It's struggling with above 50MPH. Whereas with it pinned open it'd do 60MPH with ease and a maximum of 70MPH. Now it won't even touch them speeds. Is there any form of restriction on the PV for the 1997 models? I'm guessing it's that or a problem with the servo.

When I pinned it I just literally disconnected the two cables on the pulley and did nothing else.

Luke · Guru

Is this all correct? And that's the cap welded up above. What does the lead next to the plug in (black & yellow/gold) do? I'm guessing it's a earth or something?

Luke · Guru

It's doing its cleaning cycle fine, but when I rev it up in N it only goes half way up and doesn't reach the little hole when bouncing off the limiter.

EDIT: Never noticed the "1" and "2" clearly marked on the servo and I have them the opposite way around... DOH. /facepalm Apparently I have them correct?

-- Edited by Luke on Wednesday 31st of December 2014 12:55:32 PM

-- Edited by Luke on Wednesday 31st of December 2014 01:59:51 PM

FunkeyMunkeyDavid · Guru

was the powervalve put back in the same place when refitting?

some have a diamond shaped locating pin.

they can fit in 2 different ways if i remember right?

i've put them in wrong in the past (more than once because i rush everything)

it restricted the bike in the way you've described?

Luke · Guru

I'm not sure if mine has a locating pin. I ain't too sure if it's the correct way around. I have a video of it in the exhaust port. I'll upload it to YouTube now.

When it's doing the cleaning cycle it'll line up with the hole on the L/H side. But when revving the engine it falls short of it, even on the limiter. cry

-- Edited by Luke on Wednesday 31st of December 2014 08:11:24 PM

Calum122 · Guru

You don't need to rev the balls off the bike to get the powervalve at it's most open. It will be fully open at 8K rpm as programmed by the CDI so just adjust it so when it's at 8K, it sits flush with the exhaust port. I've set my up time and time again and then even made my own powervalve curve using the Zeeltronic so I know how to set them up

Luke · Guru

I set it up to the little hole where you're supposed to stick the drill bit or something similar before doing the lock nuts. It goes to that mark when I turn the ignition on and off, but when the bike is started up, it won't go back to that little hole to open fully. That's what I'm struggling with. Because it won't open fully it's really slow through the later stages of the RPM's.

My cable for my rev thing has snapped, not that it should make a difference?

Calum122 · Guru

See that's what the manual days to do but I've never done it that way. The way I've done it is without the drill bit. Exhaust off. Please
By using your fingers feel when the powervalve sits flush with the exhaust port. The you know for a fact it's wide open. Tried using the drill bit method when I was a noob and it confused the hell out of me. And by looking with your eye you can see the powervalve move in the direction you intended for it.

Luke · Guru

Hmm, it doesn't seem to get wide open? Even in the video it doesn't look like the full exhaust port is opened up. Is it supposed to be like that?

I think the servo has gone. When I pinned it I literally just disconnected the two cables on both pulleys and rode it. It did 60MPH with ease doing that. Albeit it was boggy in the bottom end.

Calum122 · Guru

Literally to pin the powervalve all you need is make the valve flush with the exhaust port and then unplug the power. Done. That's it. Don't need to remove cables.

Now, there are two types of cables, one is shorter than the other. So you need to make sure they're the right cables. If you establish that then it's literally just going to be setting it up. It's a 5 minute job when you know what you're doing.

Luke · Guru

Hmm. It's set to the hole. It reaches the full open point when it does the cleaning cycle but when I rev it up it falls short and doesn't open fully. The long cable is on the right.
It's like it has a restriction stopping it get to the fully open position.

It needs new seals in both sides now, as it's leaking gases.

Luke · Guru

Doesn't even work with the servo disconnected from the electrics. I remove the cables again, and hey presto it's working fine again but still pinned open.

Will the cylinder being bored out all the way affect it?