1999 ktm 50 clutch issue - KTM Forums: KTM Motorcycle Forum
 
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post #1 of 7 (permalink) Old 06-30-2019, 07:35 AM Thread Starter
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1999 ktm 50 clutch issue

Recently picked up a 1999 50. I dont know much about the bike but it appears the clutch came loose and damaged the cover.

It's a 2 shoe clutch I have repaired the cover and tightened the clutch nut however when I go to start or move the bike it turns the engine over now....wont free spin....
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post #2 of 7 (permalink) Old 07-01-2019, 12:23 PM
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Is this a air or water cooled motor? 1999 KTM only used the air cooled S5-E MORINI motor.

The two clutch shoes have springs that pulls them inwards and they should not be able to touch the drum at low revs. When you kick the motor over they should not be in contact with the clutch drum. You might have some debri inside the drum, the clutch shoes or their fittings might have gotten damaged so they now touch the drum, the drum is not properly fitted etc.

Best option is to remove the clutch drum and shoes and have a good look at it to see what causes the issue. Also check the shaft to make sure it has not become slightly bent.

.................................................LET THE BRIDGES I BURN LIGHT THE WAY!
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post #3 of 7 (permalink) Old 07-01-2019, 02:11 PM Thread Starter
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So its air cooled and the shoes look perfect and are not touching

Could it just be on too tight I was worried about it coming off when riding it...
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post #4 of 7 (permalink) Old 07-02-2019, 08:34 AM
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The clutch drum drives the output shaft where the sprocket attaches to. Start by taking the side cover off again and check that all is back where it should be. If you remove the r/h side cover and put the bike on something so the back wheel is in the air you should be able to pull the rear wheel and see the clutch drum spin. The clutch shoes attach to the output shaft on the crank. If you take out the spark plug you should be able to turn the clutch shoes and get the piston to go up and down w/o the rear wheel moving.

These small bikes are not too tricky to figure out. And you should very soon be able to figure out what is making the clutch drag/jam. Come back if you are still struggling and we go through the setup step by step to identify what is the issue.

.................................................LET THE BRIDGES I BURN LIGHT THE WAY!
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post #5 of 7 (permalink) Old 07-08-2019, 03:25 PM Thread Starter
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Have you ever had a clutch basket warp when I spin it feels uneven and seems to get closer to clutch pads in places then others

I took the clutch off again because when I spun the tire with spark plug out it spun the clutch too I was unable to spin the clutch without turning the basket...
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post #6 of 7 (permalink) Old 07-11-2019, 02:51 PM
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So when you had the plug out and you spin the rear wheel the piston goes up and down?

Regarding the clutch drum: The clutch drum is supposed to be evenly round and not touch the clutch shoes when motor is not running. This should only happen at very high revs.

The crank drives the clutch shoes and when the revs are high enough, so the centrifugal force expands the clutch springs, the clutch shoes grab the drum that is driving the output shaft where the front sprocket is fitted. When turning the back wheel (w/o motor running) it should spin freely as the drum (that will spin from you turning the back wheel) does not touch the clutch shoes.

No, I have not seen a warped clutch drum. But your bike is 20 years old and it could have had a tough life in those years.

You will need to have a really close look at the whole setup to figure out what is causing this.
When going by your description in your first post "....wont free spin..." I concluded that something is stopping the clutch drum from not freely spinning while motor is not running. You also tell us that the clutch shoes had come loose and damaged the side cover. This clearly had happened at high revs (reason for the damage to the side cover) so that could also have damaged other parts.

If you take the clutch shoes and their mounting off there should be nothing that makes the piston move when you spin the back wheel.

Probable issues causing all this:
- The output shaft from the crank is bent
- The r/h crank main bearing is worn/damaged allowing the shaft to move.
- You are missing some parts of the clutch that now makes the clutch shoe mounting and the drum bind.
- The clutch shoes are not fitted properly, or they are the wrong shoes.
- Or is there some damage to the drum?
- The drum is not spinning freely on the output shaft from the crank

If this bike was in my workshop I would start by taking the clutch shoes and their mounting off and then check the drum and the output shaft from the crank for damage, that the main bearing is all good and that the output shaft is not bent. I would spin the backwheel with the clutch off to satisfy myself that all was running freely. I would then make sure that I actually have all the bits that are to be fitted together with the drum and the clutch. And satisfy myself that they are all in good order (if not I would replace any faulty ones). If this was the first time I worked on a setup like this I would find a manual for the job on the net and follow any instructions re how all this goes together. (There is a link on this page to manuals, but they are available at many sites)

Come back and tell us how you are getting on and if you have some other things we can help with please ask.

.................................................LET THE BRIDGES I BURN LIGHT THE WAY!

Last edited by Axzon; 07-11-2019 at 02:54 PM.
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post #7 of 7 (permalink) Old Today, 09:56 AM
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study morini and then study your engine and make sure which motor you have

https://www.morinifrancousa.com/parts.htm

2008 1190 RC8
2007 690 SM

racers toolbox thread

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