Home Made Quick-Lube YPVS Powervalve Cables
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Sweet! I’ve never seen those inline oilers before! Getting the length of the cables right is so important to the free movement of the motor & pulley. Seriously good thinking, bud!...
Kudos & thank you!... -
@SpookDog Thanks man
When I got my 1st DTR in 1992 we still had the 12bhp learner restriction in the UK so the bikes were supplied without PV servos fitted and the valve was pegged in the closed position. Like a lot of people at the time I ran the valve pegged open, a 10 minute job which restored the top-end power at the expense of low-end performance which was about the same as a DT50MX. It made the bike very difficult to ride off-road and as the servo kit was so expensive from Yamaha, most full licence holders just sold on their TZR/DTR and bought a bigger bike. Probably also responsible for encouraging a whole generation of teenagers to ride it like they stole it as you had to absolutely rag the proverbial out of it to make it do pretty much anything.
I also worked in a Yamaha dealership at this time and when servicing and PDIing restricted DTRs I was impressed by the low-end torque although they went flat at about 6000rpm and did about 55mph flat out as you can imagine
Then in 2020 I bought my '93 French import and the (3-wire) servo did its cleaning cycle but didn't respond to engine speed which had both me and the seller scratching our heads. A used servo cured it meaning it's possible to fry the part of the PCB inside the 3-wire servo which responds to engine speed although I'm not sure how the previous owner managed this.
So after nearly 30 years of banging my head against a wall, I was finally able to enjoy a DT125R with fully functioning YPVS system as Yamaha intended. And I realised that despite owning a lot of bigger bikes in the meantime like several TDR250s, an RD500LC and a few 90s grey import 400s, that was what I wanted the most! I mean if I'd been a teenager in France or Italy I could have had that but a bunch of killjoys in the UK made it impossible. It's very pleasant to ride around town/green lanes sensibly and have walkers and horse riders wave to you knowing you've got plenty of power if you need it. So I've learned to love my powervalve cables
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Same as. It took me a while to suss out how to set up the 3 wire servo, with back to front cables and all, but I’d never be without that low rev torque again! My bike only revs up to about 10k though, I’m hoping it’s the exhaust (big1) causing this?...
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Both cables have the same size?? Any One knows the lenght of the cables? I have 1 snapped and Im planing to make One with a steel cable from a bike's braking system
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@Hybrid_Theory01 Both cables have the same size nipples yes, 6mm barrel on the servo end and 4mm on the pulley (same as an MTB gear cable as described in the OP).
https://accessories.hitchcocksmotorcycles.com/accessory-shop/Solderless-Barrel-Nipples/11756
https://www.tredz.co.uk/.Clarks-Stainless-Steel-MTB-Hybrid-Road-Gear-Inner-Wire_129181.htm
TBH I don't know the precise length of the outer cables, because they're so short I just made up outer cables the right length with the servo installed on the bike. Inner and outer gear cable is pretty cheap from cycle shops (outer is sold by the metre) so you can afford to have a few goes at this to get it spot on
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@HOTSHOT-III i have 2 cables that i bought like 8 months ago and 2 endings ill try to find some measures cause the engine isnt mounted on the frame right now, thank you
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Check the link above ^
Sytec Motorsport Throttle Cable Adjuster & Nuts 25mm Weber Twin DCOE Linkage ADV
My adjusters snapped off in the PV housing. These are the best I’ve found. They’re not the cheapest! They’ve got a long enough ‘top’ so you can heat shrink the outer cable to it and they ooze quality…
Still love this thread!…
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@Hybrid_Theory01 the cables worked just fine, power valve is working
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Bud, thank you! I can get the PV working on the tizzer now for not to much money. The length of those (impossible to find!) cables wouldn’t of last a winter without lube ports at the highest point! Plus stainless cables!
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