Diff'rent Strokers

[2TV owner]

Yes i suppose the cables could be on the wrong way round. that does not explain why the motor joggles about at idle but then again i don't suppose that is a big issue as long as it works.

Look forward to seeing what your's does.

justin

[2TV owner]

Hi Karl,

Just wondered if you managed to get a video of the sdr ypvs? I checked the cables on mine and they are both different lengths and try as i might they were not for going on the other way so i'm sure the were right to start with. power valve is nice and free (checked it while cables off).

Justin

[arlurt]

Sorry Justin, had a shower to fix over the weekend so bike were at the back of the line. I'll get something for you this week.
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Light is right.

[arlurt]

Two video clips for you, one showing what the power valve does with ignition Off to On, and the other showing power valve action with the engine running in neutral.





Hope these help...
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Light is right.

[2TV owner]

Hi Karl,

Thanks for taking the time to do those video clips. They confirmed to me that there is definitly something wrong with mine.
your first clip with the cleaning cycle is the same as mine. The second clip however is different to mine. From the clip i can see that when your bike is running the valve moves anticlockwise to the closed position (mine does this) but your valve does not move whilst at idle (this is where mine is fluttering) when you rev your engine to what sounds like about 5-6thou your valve moves towrds the open position or clockwise(mine will move in the same direction but literally anything above idle and will stay there till it returns to idle then it will move back anti clockwise but again start to flutter)

So I now need to know if i have a faulty YPVS controller or servo. I have checked all of the readings on my servo against a known good second hand unit but i was unable to plug it in and confirm this. Definitly not the cdi as i have bought one and tried it. If it turns out to be the controller then i will be looking at an Ignitech STPS or Zeeltronic unit.

Don't suppose you fancy plugging my controller in to yours to see if the controller is at fault? I don't know what else to check and don't want to start buying ecu's or servos if it turns out to be some other influence from the bike.

Thanks

Justin

[2TV owner]

Just a running update on the SDR. Not been riding it due to the power valve problem but I have been keeping it running, it's at work so its easy to have a play with it in my lunch break.

The other week it kicked up 2nd kick and was idling ok. I took it round the yard at work just to keep everything turning and as i came back in it died on me. kicked staright back up but would not rev much above idle. Hmm, possibly some dirt has got in the carb ( i have had the tank off about 30 times)

So off came the carb and after reading arlurts post about removing his carb i realised what he meant. The bike looks so easy to work on until you actually have to!

A strip down of the internals revealled my susspicions of a partially blocked emulsion tube/needle jet. This was cleaned out with carb cleaner and compressed air and refitted. I checked all of the other jets and found to my suprise that it had a 125 main jet in there? all of the info i have on the bike says it should be a 175. an iternet search found a guy in Liverpool at a place called motocarb, very helpful and at £3.50 for a main jet i wasn't complaining (it's a yorkshire thing we're not tight just careful!).
Anyway parts came in the post and the carb is now back on and it revs cleanly once again.

The power valve is the next thing to sort. I am going to send my controller to a guy in Greece at the two stroke race lab. He says if it can be fixed he will do so. also while it is there he will carry out his mod which is to install a series of tiny switches which make the ecu 'programmable' by altering the power valve operation. It also means that the ecu can be fitted and set to work on any YPVS Yam engine.

will update as and when,,,

Justin

[2TV owner]

Running update!

Ordered an Ignitech STPS YPVS controller today, hopefully should be here this week

[arlurt]

Good luck, hope it fixes it for you.
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Light is right.

[2TV owner]

Thanks!
the way i look at it is that is it's got two choices I'm hoping its here this week as i'm on holiday for a couple of weeks after that so it would be nice to put an end to it and get out on the bloody thing.

Justin

[2TV owner]

Just back from holiday and the Ignitech unit has arrived to hopefullly cure my YPVS woes. It's a nice piece of kit, has all the correct plugs on it just to plug in to the rest of the bike. Also they have sent software on a CD so that the operation of the power valve can be tweeked via a laptop
Watch this space!

[arlurt]

Looking forward to hearing how you get on.
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Light is right.

[2TV owner]

Ignitech unit fitted today in my lunch break, but i couldn't get an rpm signal to display on the software and the power valve after doing it's cleaning cycle would not work at all
I emailed Ignitech as their diagram suggested that the pick up for the rpm signal came from the low tension side of the coil. This was incorrect and they replied and said that they use the Yamaha CDi output that the normal YPVS uses (Black with Yellow tracer). After a quick swap of the wires i finally got the power valve to work as it should All that i need to do now is have a play with the software to make sure that it goes ok and that the power valve is not coming in too early or too late, but this can be done infinitley with the software. I will probably look for an rs232 lead to plug into the ignitech and terminate it near the battery as its quite difficult to plug in to change things without removing the tank to get in there. I'm quite good at getting the tank off an SDR now and if anybody wants to try and beat me at it you're gonna loose!

I'll get some pictures up of the install. I'm very pleased with the unit it looks very well constructed and finally i have a bike that i can actually ride although a 25 year old two stroke means i may be posting on here again!

Thanks to all who have read the posts and also offered suggestions as to what was wrong. Might actually get to Sherburn on it now!

Justin

[2TV owner]

Here are the pictures of the Ignitech YPVS controller. It fits in the space left by the original Yam YPVS controller. There are no mounting lugs on the Ignitech so i used some really good double sided foam tape we use at work, sticks like shit to a blanket!
As i mentioned before its plug and play as they fit all the proper connectors to plug staright in to the original loom and servo.

I found that when i hooked up the laptop to make adjustments i had to dangle the unit at the right hand side of the frame as you need the bike running and so the tank has to be on and then you can't get in to plug the rs232 cable into the ecu. So i bought a 2metre rs232 cable and have plugged it into the ecu permenantly and run the excess cable to under the seat area so that next time i plug in it will just need the seat unit removing.

[Top-shaggy]

Great thread and pics there fella
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We are where we are...

[2TV owner]

Thanks, it's been a long battle!