Author Topic: '81 KTM 250GS rebuild  (Read 17940 times)

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Olddog

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Re: '81 KTM 250GS rebuild
« Reply #45 on: January 01, 2013, 03:10:50 pm »
Smithie i mistook your KTM for a modified Adventure there for a bit, but i see theres much more too it, nice work! The Duc is ok but like te KTM its nose heavy. I'm about to pull it back down and fabricate up a new set of triple trees for it which will give the forks more offset so less trail, should steer better then :) Then next will be fabricating up a complete new swingarm.

Rego wise, thats good news about the compliance plate, mine is almost unreadable as the back of the headlight rubs on it. RE: Vintage rego, you're right about it having to be a club run but I reckon I can get DSA to invite the club along which should sort that out....I hope.

I have some news also that Steve Smith and some of his mates are running an all dirt ride kicking off from Bathurst up to Bourke for the rally. From what i hear this will be a well organised trail ride, with sweeps and I think a support vehicle. As mentioned I'll be doing it real easy so if guys want to go and get serious as well, then Steves ride might be the go.

Now, back to the bike build!
I'm about to start nailing the engine back together and found that I don't have a bearing for the gearbox intermediate shaft, a Steyr 98203 so I'm stumped for the moment. When the local bearing guy opens tomorrow i'll order one. I've found that a New Holland tractor sealed beam will replace the standard 6 volt one, once that turns up i'll start on wiring in the 12 volt total loss system.
Smithie, ignition wiring wise, I'm right in thinking i can just take the wire off the motpplat ingnition and run it straight to the coil?
Now there was a comment regarding the reliability of the standard clutch. I measured the plates and they are in spec, the springs weren't so i got new ones of those. Will it stand up or should i be modifying jap ones to suit? Bearing in mind that I'm not racing so i can be just as slow as i want shifting gears etc :)

Cheers all!

Bill

Offline ozktm

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Re: '81 KTM 250GS rebuild
« Reply #46 on: January 02, 2013, 05:46:10 am »
Bill,

The bearing you are after can be sourced, took my bearing suppliers a while to find but they are available. Possibly a wait to get them though. I think they are used in other European automotive types.
Let me know if you are struggling to find one, i have some used ones out of motors that will get you away, still good.

Adrian
Regards,
Adrian Goold #101

'72 KTM 175 |'74.5 KTM 250 |'74.5 KTM 400 |Hagon/KTM 250 proj|'76 MC5 250 Project |'76 MC5 400|'78 KTM 250 Project |'81 KTM 250 MC | '81 KTM 495 MC

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #47 on: January 03, 2013, 09:15:52 pm »
G'day Adrian, thanks for the offer mate, I went down to the local bearing bloke and he reckons he can probably source one. I'll see how he goes but if i come up dry I'll let you know.

Cheers

Bill

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #48 on: January 05, 2013, 06:24:40 pm »
Looks like the bearing bloke can get me the bearing.....maybe, gotta wait til the end of next week. While iI was going through the bearing interchange book I noticed that the 6203 bearing is the same radial dimension, bu 5mm thicker. So I bought one and notice that if I remove the circlip where the bearing goes I should be able to fit this bearing and not foul the clutch, has anyone tried this mod before? I'm sure I'm not the first person to notice this?

Cheers

Bill

Offline supermoto.mc

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Re: '81 KTM 250GS rebuild
« Reply #49 on: January 06, 2013, 10:06:27 am »
your joking mate

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #50 on: January 06, 2013, 10:37:07 am »
Joking about ??

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #51 on: January 07, 2013, 07:43:39 pm »
notice that if I remove the circlip where the bearing goes I should be able to fit this bearing and not foul the clutch,

Er yeah so figured out why it wouldn't work, if i take away the circlip i have nothing stopping the clutch actuator from smacking into the back of the bearing  :-[ Heh heh

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #52 on: January 13, 2013, 08:34:58 pm »
Getting there, engine back together and in the frame


Olddog

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Re: '81 KTM 250GS rebuild
« Reply #53 on: January 28, 2013, 09:36:13 pm »
Evenin all, Bit of an update. Progress has been slow, finally got a chance to spend some time on it over this long weekend, doing the wiring etc for the total loss 12 volt bits. I tried to get it running today but seem to have developed a sudden loss of spark! >:( I had good spark when I tested it this morning, before fitting the expansion chamber and tank. I filled it up with juice then kicked and kicked and kicked but no noise! On inspection i see that the spark is now very erratic. I've done the tests set out in the manual, ie blue wire to ground ohm check and blue to black wire ohm check and they come up okay. Anyone else had trouble with their ignition? Could the coil have packed it in? This bike is starting to push the boundaries for me as far as having it going and ready for the big ride on time. I'm starting to think this thing is gonna get shelved and I'll get one of the XR's going instead.

Cheers

Bill

Offline Moto

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Re: '81 KTM 250GS rebuild
« Reply #54 on: January 29, 2013, 09:15:02 pm »
Try puting a ground wire(temporary) between the Motoplat stator and the coil/frame,you could have upset the bond when you had the engine out. I always run a separate earth with the blue and black wires between the Motoplat and the coil/frame to stop these types of problems. Also disconnect your kill button.

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #55 on: January 30, 2013, 07:36:15 pm »
Hi Moto, thanks for the info. Please bear with me here, but where on the stator do you fix the earth wire? I can only think of using maybe tone of the mounting screws? Then tucking the wire under the flywheel perhaps? I'm a bit new at this Motoplat stuff.

Cheers

Bill


Offline Moto

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Re: '81 KTM 250GS rebuild
« Reply #56 on: January 31, 2013, 08:04:51 pm »
As a temporary measure,to see if a bad earth is your problem.A wire under any of the backing plate mounting screws will do fine.Then connect the other end to one of the top coil steel mounting tab bolts.Put the fly wheel on as normal.

Olddog

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Re: '81 KTM 250GS rebuild
« Reply #57 on: February 13, 2013, 06:45:11 pm »
Moto, I tried the earth wire trick this weekend and no dice unfortunately. I did notice that if i spin the engine over really fast then it starts to generate a spark, so my thinking is that I've upset something in the windings during the rebuild. Fair enough really, its been sitting for a while and everything else has been rebuilt so why not do the ignition as well? Trouble is theres no way I'll get the bike going in time for the scrapheap ride now, so it's packed off to the back of the shed and I'll go back to getting the XR600 ready.

Had some good fortune with the Ohlins shocks too. I sent them to RAD shocky repairs in Brissy, they cleaned em up, straightened and re hard chromed the shafts, sels, oil etc etc all for $280!!! Anyone else used these guys?

Thinking of selling the 250 actually (if anyones interested)and getting a 495 after making the mistake of reading the article about Adrian and his sweet looking bike (my god thats nice).

Cheers

Bill