Hi guys require help ypvs diagnosis

[sulli]

I have an australian 1988 rz 250 which is being converted to a track bike same as rd 250 english version full fairing round headlight white painted wheels fn model I think??
Any way power valve was not going through self clean process at ignition on but was juddering servo motor moving slightly back and forward but not moving valve after checking connections and recharging the battery I am not getting any life from the ypvs at all any suggestions reallt appreciated as i have haynes manual but the manual doesn't give any real trouble shooting on ypvs

Oh by the way I'm in Sunny Queensland Australia and have owned the bike for 10 years
regards Sulli

[Norbo]

Gday mate

dos'nt sound like a big problem.

Remove your cables and spray WD40 down them they may well be dry. If when you take them off they are real stiff you may have burnt out the servo motor. Have a look at the joint between the valves they are often worn. It is most likely that the controle box has broken. But i would still remove the cables first and cleen them if you turn the bike on after they are removed and the servo still wont turn you know its the motor ir the box for sure.

[sulli]

ok will do the cables on the weekend and post progress
regards sulli

[sulli]

ok here's the update pulled the servo motor off cables were a bit stiff so are soaking.
Dismantled servo and connected up to battery works yea!! connect up to the wiring harness doesn't work connect probe to the neg side of the battery to check for impulse from controller and switch ignition on light powers up for about 10 seconds and goes out on the probe buuut servo motor doesn't work.?
Connect it all back up again place probe on negative wire to servo turn ignition on and get a little action.
Correct me if I'm wrong but I 'm thinking that a bad connection or earth
Or can this be caused by a faulty potentimeter thing in the servo assembly atm I dont have a multi meter but looking for the cheapest way to resolve this issue

[sulli]

servo seems good wiring appears to be the prob all gears are like brand new done the test like mr haynes suggests and it comes thru with flying colors
battery is charging atm so will investigate tomorrow and may be visit dick smiths for a multi meter

[sulli]

fark this web site is heavily moderated just tried to post duck with an i as a second letter and it wrote something else

[sulli]

stiff upper lip i suppose

[sulli]

going to clean the block connectors and check resistance before proceeding much further thanks for the offer of a servo will keep than in mind

[Norbo]

sulli said:

fark this web site is heavily moderated just tried to post duck with an i as a second letter and it wrote something else

;D ;D ;D Its set on auto, my kids look on here when they go back to ther mums . They like to look at peopls bikes so i dont want any foul language, I want to keep it a clean site frendaly ;D ;D ;D

[sulli]

ok thanks norbo thats cool. i just couldn't believe that "thingy" thing
nice to see a responsible parent

[vinze187]

oooooo think we should stop all the how do you eat yours kind of topics!!

[Norbo]

vinze187 said:

oooooo think we should stop all the how do you eat yours kind of topics!!

;D ;D ;D

[sulli]

yes and no got a multi meter monday and had a talk to my technical at work ahve to re assemble the units to fond the fault terry who i spoke to explained that the best way to fault find a problem like this is under load and to measure the voltage as this will pinpoint the area of problem quicker it does make sense as resisstance readings on a multi meter are in milliamps and will flow thru a single strand and appear 100% ok yet under load they will only provide 2v out of 12v
So some progress thanks for asking
will work on it on the weekend and post if successful
regards Sulli

[Norbo]

Lets hope its something that can be fixed rarther then something that has to be replaced.

[sulli]

ok heres an update checking the potentiometer using the meter i get different readings depending on the position of the servomotor in a certain position all the readings are below .75ohms at another position the readings are above I assume that this is correct or is there a home position on the servo for the readings as the manual is not clear on this
Any suggestions
thanks

[Norbo]

Can you borrow anyones control box I think that is your problem. Just swop it over and see. You must know some one even a shop that has one in that you can borrow of for a few mins to test it out side the shop.

[sulli]

bike is being setup as a track bike no rego i think you blokes call it a "MOT" correct me if i'm wrong any way have plenty of time next track day is after christmas will look at the the control box shortly but first will establish that all the wiring is carrying the correct current but its frustrating any way went for a ride on my other bike today had a great day with mates

[sulli]

Queensland Australia "Beautiful one day perfect the next"
you should know "AUSSIE AUSSIE AUSSIE"

[sulli]

m8 thats our up and down raceway in the wilderness
p.v. will come in time i hope

[sulli]

hi guys had a chance to work on the rz today checked out the pv readings for the servo
blue/yellow+black/white =8.47
blue /yellow +red white =5.83
red/white + black white =5.27
as the tolerances are +or-30% =9.75 ohms upper limit
lower limit = 5.25 ohms
so can any one help with a controller unit as this is the next step
if so what price???
preferably in aussie dollars

[sulli]

bty did take piccies and will post them shortly for reference in the future ;D

[Norbo]

malibrew1 said:

Make sure to look at the schem and see if any other wires are spliced in-line w/it. I had the same prob. it turned out to be a wire that was spliced in as part of the stock loom. Super cheesy on yamaha's part to draw power from a vital organ such as the pwr valves. Ya never know!

Worth a try you never know.

Hi Malibrew welcome to the forum . What bike do you ride?