How to remove flywheel - 1990 350 F2 2UA

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kjellz
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How to remove flywheel - 1990 350 F2 2UA

#1 Post by kjellz » Sat Sep 30, 2017 12:40 pm

Hi all.
Looks like I need to replace my YPVS F2 - 2UA stator.

I wonder if anyone have tested this one ; http://www.wemoto.com/bikes/yamaha/rd_3 ... _electrex/" onclick="window.open(this.href);return false;

I could use any tips and tricks to get the flywheel off as well, as mine seem to stick quite a bit....
I actually destroyed the flywheel puller (center internal/externally threaded 2-piece type) I had laying around today in my first attempt. (must have been a poor quality one - the center threads stretched out)
But should I have apllied heat or anything as well? And also wonder if you use air tools on the pullers?

Also when measuring the resistance between the 3 white wires they all show infinite resistance- or open line. Is this common? I mean is this how these stators die - all 3hree phases fail at the same time?

I put up parts wanted request in the corresponding section- but if anyone can reccomend a rewinding service in Europe I would like to hear about it please.
As for the flywheel puller, can anyone recommend a specific brand or part number that actually works and have stood the test :-) ?

Greetings from Norway
Kjell
Last edited by kjellz on Sat Nov 18, 2017 6:58 pm, edited 1 time in total.
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RD350 YPVS 1990
N2 Red/white - F2 conversion
Figaroli pipes

MK
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#2 Post by MK » Sun Oct 01, 2017 6:19 am

All 3 failing is not very likely.
If all 3 are "the same" it's pretty likely that they're ok.

It's more likely that you have a very cheap multimeter that cannot cope with the 0.6 Ohm resistance. Set it to ohm and to the lowest possible range. Then measure white against white. It should be some 0.6 Ohm, but anything berween 0.3 and 0.9 would be ok.
Then measure each white against ground (engine, frame, or black cable on the generator harness). That must not have any connection (i.e. it'll show infinite resistance if ok)

Concerning the puller tool: They're all pretty weak material and I quite executed some of them.
First thing is to remove all washers that are under the rotor nut. If you leave them in place, they're only a few threads tgat hold the load and they'll fail very quickly.
Second thing is warming up. Don't make it too hot on the outside. Magnets are glued in and don't like that. Only warm up the center hub and then screw in the puller.

Another additional method is to let some WD40 or Ballistol soak in over night and try again next day.
Bye
Martin

kjellz
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#3 Post by kjellz » Sun Oct 01, 2017 1:24 pm

Hi
Thanks for your response.
My multimeter should be good - it is brand "Fluke" and was pretty expensive when i bought it.
When i touch the probes togehter it shorts out, indicating it Works at least. But I will play with the range settings though, instead of "auto" if the result shoudl be as low as 0.6 Ohm!

Will try the heating thing as well - paying attention to the magnets for sure.
Thanks for letting me know.

Update to follow:-)
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RD350 YPVS 1990
N2 Red/white - F2 conversion
Figaroli pipes

kjellz
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#4 Post by kjellz » Sun Oct 01, 2017 3:27 pm

Hi
Checked the measurements again.
Absolutely infinite resistance between all three phase windings!
Also double checked with the continuity tester function - no biip sound either. Its just all dead. Puzzling!
I will have to pull the flywheel off to find out more anyway.
Now waiting for a new puller, a "Venhill M27x1 mm Left" i found on ebay. -looks strong, and not universal with different threads in either ends like to one I busted in the first attempt....
Last edited by kjellz on Sat Nov 18, 2017 6:59 pm, edited 1 time in total.
----------------------------------
RD350 YPVS 1990
N2 Red/white - F2 conversion
Figaroli pipes

evan_calgary
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#5 Post by evan_calgary » Mon Oct 02, 2017 3:42 am

The KTM pullers are the same dimensions (250sx 200*).

I typically tighten down the inside bolt then hit it with a hammer a few times and slowly tighten repeating the action. Flywheel will usually pop off.
Saves stripping the head or threads. There is a slight risk of mushrooming the end of the crank but have not had it happen.

waltmil
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#6 Post by waltmil » Mon Oct 02, 2017 5:09 pm

Just back the nut off 2 or 3 threads before you use the puller. Prevents mushrooming the crank end and the flywheel doesn't go flying when it comes off.
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kjellz
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#7 Post by kjellz » Mon Oct 02, 2017 5:17 pm

Thanks.
I actually killed a second puller today and I did notice some of that mushroming as well after trying to convince it with a few blows. But at this stage the threads of the puller had already begun to fail.
But also this second puller was what I would caracterize as a poor quality one from one of the discount tool stores. The steel seems really soft?

Anyway, I will have to wait a week or so for the more serious (at least I believe it to be) puller i ordered off ebay before trying again.

But I am becoming increasingly worried of how this will go after having applied so much force without any success yet..........
And I do not want to heat it to much either as the other post here pointed out with regards to the magnets being glued in.
----------------------------------
RD350 YPVS 1990
N2 Red/white - F2 conversion
Figaroli pipes

hondaror
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#8 Post by hondaror » Mon Oct 02, 2017 8:42 pm

Impact shock is key. Every time you advance the threads, a good smack.
Rory

MK
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#9 Post by MK » Tue Oct 03, 2017 5:48 am

Have you already used WD40 or Ballistol?
That could soak in for the week until the new puller is there.
And yes, they're weak. Partly thats a security fature to keep the rotor threads functional ...

Don't worry too much about heat.
Use the torch at the center hub and test with your hand on the outside if it's getting too hot there.
In a running engine the stator gets hot, too and that transfers to the rotor. I guess a 100 deg C should not hurt.
Bye
Martin

kjellz
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#10 Post by kjellz » Tue Oct 03, 2017 7:30 am

Thanks for all your input guys.
----------------------------------
RD350 YPVS 1990
N2 Red/white - F2 conversion
Figaroli pipes

kjellz
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#11 Post by kjellz » Fri Oct 13, 2017 4:35 am

I ruined another puller again.
Which also means the flywheel refuses to come off by the force required to rip the threads of the center bolt of the puller. What next? I ordered a new puller and I am seeing myself in the future torching the flywheel with an acetylene burner with a big grin on my face :-). 3-0 to the flywheel so far. Must be rusted at the axle/hub. To be continued....
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RD350 YPVS 1990
N2 Red/white - F2 conversion
Figaroli pipes

Headcoats
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#12 Post by Headcoats » Fri Oct 13, 2017 4:49 pm

Heard putting the flywheel puller under tension then pour boiling kettle over the flywheell
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#13 Post by gpaddict » Fri Oct 13, 2017 8:52 pm

I need to ask, what brand of flywheel puller are you guys buying? I ask because I've had my same one for many years, and as many of us know, that particular puller fits a lot of different motors, and as such, sees extensive usage. Mine is a Motion Pro, cost is in the low 20 dollar range, and I highly recommend it.
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#14 Post by two-stroke-brit » Sun Oct 15, 2017 5:39 pm

gpaddict wrote:I need to ask, what brand of flywheel puller are you guys buying? I ask because I've had my same one for many years, and as many of us know, that particular puller fits a lot of different motors, and as such, sees extensive usage. Mine is a Motion Pro, cost is in the low 20 dollar range, and I highly recommend it.
thats what i use to . :smt023
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RZed
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Re: How to remove flywheel - 1990 350 F2 2UA . Electrex Stat

#15 Post by RZed » Sun Oct 15, 2017 11:34 pm

One small thing I learned the hard way is to make sure the thick washer under the flywheel nut is removed before using the puller.
I had one stay in place without realizing it and the puller didn't thread all the way in to the bottom, and kept stripping the threads off the puller because there was only half of the them engaged. :smt013

Just my 2 cents,

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