Should my power valve cables look like this?
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Hi, I've been reading this forum for years as it seems to be the best place to get advice on anything related to DTs but this is my first post.
This is my french import 1993 DT125R I picked up from Unit 5 some years back. It's my second DT, with my first being an early 2000's blue supermoto when I was in my 20s. 15 years later I decided to try and recapture my youth by picking up another and got this Pinky.
However it sat around for a few years now and unfortunatly it spent a lot of time outdoors (under a cover) and ended up with a crankcase full of water and needed an engine rebuild.
So a few months ago I took everything apart and put a new crank, bearings, rod and piston in it. Anyway I've finally got everything back together, but I'm not conviniced I've got the power valve right.Mostly I'm just looking to see if everyones bike looks like this or if I've done something wrong?
As you can see from the photo below the adjuster on the left is wound almost all the way out putting a big kink in the cable and making the servo work harder. I can't imagine this is how it's supposed to be but it seems to be the only way I can get the two pin holes to line up on the cam and case. As far as the cables I've got 1 going to 2 and 2 going to 1, fairly sure this is correct. With the exhaust back off and my fingers up the port the edge of the power valve feels flush with the top of the exhaust port and the pin holes line up after cycling the ignition. When I put the ignition on the cam turns clockwise about 45 degrees and then back to lined up. Also if it makes a difference I have the diamond power valve with square hole in cam.
Note the reason I'm looking into this isn't just because it looks wrong but also because the bike doesn't seem to be making the same power it was a few years ago. I'm sure before the rebuild I could get it off the clocks at about 80mph+ (130kph), but although in lower gears it will rev right round to about 11k, in top it won't pull more than 60mph (100kph).
Any feedback appreciated.
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Hi there,
Lovely colour on that bike!
https://www.youtube.com/watch?v=9eopT_gyAo4
There is a video of my powervalve in operation.
It sounds like your adjustment of the valve is how I'd recommend it. Yes the cabling looks weird, but that could just be down to worn/stretched cables so might be mis-leading to go by.
The valve moving clockwise, relative to the photo you've uploaded, sounds right.
My advice to identify issues with powervalve and whether this is the fault is to merely pin and disconnect the valve and ride the bike from there. If the bike is dead and revs flat out then you know it's a powervalve issue. If there is no change in performance at the top end then something ele is the problem and we can go from there.
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@Bilbo9000 As @Calum says it looks/sounds like you've got the powervalve adjustment correct.
One thing I noticed when I bought some pattern powervalve cables from Yambits is the inner cables are very slightly the wrong length, meaning one of the adjusters only had like 4mm of thread engagement with the pulley housing when correctly adjusted; looking at your pic this could be the problem. I can't remember if the outers were too long but it's a common issue with pattern cables.
Genuine cables are better but they cost £20 each which is expensive for a short cable; they also don't retain lube very well as they're vertical, plus if you want to lube them properly you have to take them off, then readjust the YPVS every time. So this was my solution:
https://dt125r.co.uk/topic/2971/home-made-quick-lube-ypvs-powervalve-cables?_=1725612447259
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Just went to inspect my 93 DTR and it does have a little kink in the 1 cable not quite as much as yours did try get some pics but its behind the panel and also behind another bike and then bluetooth refuses to send to my pc haha let me know if you do need though and i'll get them uploaded hopefully Calums vid and both these lads advice gets you sorted out best of luck and really like Pinky
Hope you get out on her soon happy DTR'ingEdit managed to get the pic online soz if they aint great angle was hard ot get too hope it helps anywho
Let me know if you have no joy and i'll get some better pics soon as weather allows
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Thanks for all the replies everyone. Maybe I do just have a set of pattern cables on then. Got the bike back together with the PV pinned for now ready to try in the morning. If the top end pulls the same with it pinned and I know it's not a PV issue I've got then I might go ahead and do the MTB cable conversion HOTSHOT posted about. Really like that inline oiler setup and would be nice to get the kink out just to take the strain off the servo.
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So took it for a ride today with the PV pinned and all that happened was I lost all the bottom end power under about 6 to 7K. Top end once it came onto power was the same as before. So seems my PV is working fine even with the kink in the cables. Still going to do the bike cable mod though will post back in this thread when I do. But for now I'll start a new, more relevant thread to do with the lack of power.
