The Yamaha 2MA workshop manual I have states that the resistance across the terminals of the pick up coil should be between 94 and 140 ohms (at 20 degree C). Mine is reading around 240 ohms.
I have spoken with Westcountry Windings and they are telling me that 240 ohms is in specification for a TZR and 94 to 140 ohms is the spec for an RD350.
So:
- What does anyone else's manual/technical data say the resistance should be for a 2MA
- What is the resistance for other TZR250 models
can anyone add their knowledge on this subject?
Thanks
Bob
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My reading was 259 Ohms. you still having problems?
Electrex World Ltd. sell various new pick-up coils amongst other electrical parts but you need to determine which (if any) are suitable for the 2ma/1kt going off their available information.
http://www.electrexworld.co.uk/acatalog/Online_Catalogue_Pick_up_Coils_160.html
Hi - my 1989 TZR250 is giving a reading of 234 ohms for the pickup coils. Its been like that since I got it. Doesn't seem to cause any running issues... Although I'd rather it was closer to the figures quoted in the workshop manual too!
Quote from: Bob the B on October 10, 2016, 03:06:56 PM
...can anyone add their knowledge on this subject?
Is your TZR from 1988 or later? If so, I think your pick-up coil is OK. Here's why:
The November 1985 1KT workshop manual states 93.6-140.4 ohms
The 1987 2MA workshop manual states 94-140 ohms
The March 1988 2XT workshop manual supplement states 188-282 ohms
The February 1989 3MA workshop manual states 188-282 ohms
The change in specification seems to coincide with the change from separate CDI and YPVS control units to a single integrated unit...which I think occurred for 1988 models.
Aside from the above; If the bike is working well, it must be OK :)) .
Regards,
James
James
What you say seems to make sense. My 2MA is a mid 1988. What do I need to look for to check for an integrated CDI/YPVS unit?
The problem I have is that it's never run properly since I bought it as a non-runner. I'm in the middle of an engine rebuild and want to be sure everything is in specification hence my question.
Thanks
Bob
Quote from: Bob the B on October 11, 2016, 01:33:22 PM
James
What you say seems to make sense. My 2MA is a mid 1988. What do I need to look for to check for an integrated CDI/YPVS unit?
Thanks
Bob
A previous 1990 2ma I owned had separate cdi and ypvs units as has my 2 current 1kt's.
I am quite sure that neither of these models had integrated cdi/ypvs unit,the TDR250 definitely has.
I don't know about the 2xt and 3ma models regarding the cdi and ypvs units.
Therefore Bob,your 2ma should have 2 separate units,one either side of the rear frame rails.
YPVS unit like this on the left:
http://www.ebay.co.uk/itm/Yamaha-TZR250-1987-1KT-Electronic-power-valve-servo-CDI-ECU-motor-control-unit-/262652659633?hash=item3d275187b1:g:0yMAAOSw1DtXKf4T
CDI unit like this one on the right,but marked up as maybe 2ma/2my/2me and not 1kt-50 like both of mine are:
http://www.ebay.co.uk/itm/YAMAHA-TZR250-TZR-250-2MA-1KT-IGNITION-CDi-ECU-UNIT-/262629704017?hash=item3d25f34151:g:81EAAOSwMtxXtWlX
As far as I know
- TZR250 1KT or 2MA (any years) have separate CDI and YPVS boxes
- TZR250 2XT (in 1988 in Japan) have CDI and YPVS in one box (same as TDR250 or 3XC)
- 3MA and 3XV are other animals ;)
Oh Boy! so much to learn!!
I have separate YPVS and CDI (marked 2MY) units.
If I could bring the thread back to pick up coils. I'm still wondering if a resistance of 240 ohms is in or out of spec for my mid 1988 2MA?
From what I'm hearing I think it probably is OK based on what James says and what others have measured.
If the pick up coil was out of spec what symptoms might I experience?
Thanks
Bob
Hmm...I wasn't sure whether 1988 and later "export" models had separate or integrated CDI & YPVS control units, so I'll defer to those who know! However, 1988 may have been the year that Yamaha chose to change the specification for pick-up coils, regardless of whether they were used for JDM or export models.
Can anyone advise whether 1988 and later export models have the exact same CDI & YPVS control units as earlier models? Since the later pick-up coil resistance range is double that of earlier ones, it is possible that the coil is wound using a greater number of turns of wire which is of a smaller cross-sectional area. This should mean greater output voltage, but with less current. I don't know enough about the rest of the circuitry to draw any definite conclusions - perhaps the new pick-up coils are/were designed to work with the earlier CDI units as well as the later integrated CDI & YPVS units... ?:-| . If anyone has a workshop manual and/or parts catalogue for a later export model, perhaps that may shed some more light on the topic.
Has anyone got a workshop manual for an R1-Z and can let us know the pick-up coil resistance range? I would expect it to be the same as later model parallel twin TZRs (i.e. 188-282 ohms).
Quote from: Bob the B on October 12, 2016, 03:34:10 PM
If the pick up coil was out of spec what symptoms might I experience?
It depends what you mean by "out of spec". I doubt that a few ohms either way would cause any problem, BUT you would have to know exactly what is inside the pick-up coil package and in the CDI unit. I would generally expect that firing would be inconsistent or non-existent.
I'm not sure exactly what else is contained in the pick-up coil package - I have found pick-up coils on other makes which have resistors in the circuit, meaning that you are actually measuring the resistance of the resistors also, not just the coil(s). If anyone decides to dissect a TZR pick-up coil, let us know what's inside!
Practically speaking, the best/easiest way to diagnose faulty components like this is to substitute them and then see whether the bike runs any differently. If it runs exactly the same, there is a good chance that the component is not faulty and the poor running is being caused by something else...often something to do with the carbs :-\ .
Regards,
James
I've to start my 2XT in the week-end... so I'll measure the coil resistor if I don't forget !!!!
Value should be similar to TDR250 because they share the same CDI hardware.
So TDR250 spec should apply.
Just checked mine. I have both separate cdi and power valve control unit. my cdi looks brand new so I don't know if previous owner replaced it to fix running problem. My bike was first registered in may 88
I have just checked my CDI and the part number is 2my-50 07000-1730 QAB73. ive had a look on fowlers and they dont match. the 1988 model. Is it possible its the wrong cdi?
Thanks John
2MA CDIs are either 2MY50 or 2MY51
I've measured my 2XT pickup coil : 210 Ohms