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Post Info TOPIC: Sprag Clutch--what does a bad one sound like?


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Sprag Clutch--what does a bad one sound like?
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Hello, I'm new to the TTR-250 and new to this forum. While perusing the information available to perform some routine maintenance on a TTR-250 I just purchased, I came across several threads regarding bad sprag clutches. That's when it hit me--my bike may be experiencing the loud bang at shutoff that's referenced in these posts. I notice it almost exclusively when trying to start the bike when it's cold. After I turn on the choke and try to start it, the engine runs for a couple of seconds and stalls. When that happens, there is a loud noise. I suppose it could be described as a bang. It is very noticeable.

When I start the bike again (usually with the choke off as its very warm here right now), it fires right up and settles into an idle almost immediately (I may have to feather the throttle for just a few seconds). The bike runs fine and when I shut it off after it's warm, it does so immediately with no loud noise. And also after it's warm, it restarts easily without the loud noise it makes when it is cold. Could this be the bad sprag clutch people are referring to?

Reading about this problem is one thing. Can someone point out a video to me so I can actually hear what a bad sprag clutch sounds like? I've done some searching for one but haven't come up with anything.

I purchased the bike as a gift to my son. I would really hate to give him a bike that may fail when he tries to start it.

Thanks everyone!

 



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I ignored the bang and ended up stripping the starter splines. 

I got the sprag from partszilla and a second hand starter 

Sounded ok but a sudden bang when stopping the engine 



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Did you do the work yourself or take it to a shop? I usually do easy stuff like oil changes and chain adjustments--I've never had my hands inside an engine before. Plus, I'm not wanting to drop a couple hundred dollars in parts and labor for something that turns out was OK all along.

That's why I was wondering if anyone knows of a video that shows the problem firsthand so I can see, and most importantly, hear it so I can see if my bike is doing the same thing.

 



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Brian has a how to replace the sprag tutorial on here 

It's a fairly easy job . With mine taking the aftermarket bash plate off and on was the hardest part .

Tip if you don't have a flywheel puller the rear axle works well 



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I believe I found that tutorial. I also found a YouTube video that shows some of the procedures. Did Partzilla have the OEM Yamaha parts that everyone recommends? I'm hoping it's not to hard to find the parts I need in America.

No, I don't have a flywheel puller. That's a neat tip to know that the rear axle can be used to remove the flywheel.

Since I'm new to the site, can you please tell me who Brian is? I assume he is a moderator or the site's owner perhaps?

Thanks

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Partszilla had genuine yamaha parts and a lot cheaper than here in Australia 



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brian is our ttr god very helpfull gentleman he started the forum & was the owner & founder of totally ttr s now our totally ttr s owner is steve again very helpfull you will find help on here if you get stuck just ask the questions

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There is a thread  on the site started by Brian  tilted another jammed sprag clutch might be worth a read 

 

 



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I got my TTR out of a paddock.

It's been making a loud bang, sometimes on electric start up, sometimes when I turn it off - key, kill switch or sidestand - for 20k km now.  No better, no worse.

I suppose I should do something about it.  I'llgetaroundtuit.

 

 

 

 



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In the Riverina.

'73 RD250, '80 XS1100, '81 RD373LC, '96 Tiger 900/sidecar, '02 TTR250, and another XS11 - this time a chain drive Period 5 race bike that may be ready to race eventually.



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I would or you could be looking at a big repair bill .



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totallyttrs.com

 



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I put mine off and it took the splines off the starter 

Got all the parts from patrszilla and a second hand starter 

 

If you replace the sprag before it goes bang it's so much cheaper 



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On my previous TTR, it was making a loud bang though not all the time.Upon stripping it everything looked OK.However I opted for a replacement sprag bearing and gear, from Ali Express at around 75 GBP.Slightly different to original as can be seen in photo.It cured it but how long it may last is anyone's guess.I sold the bike and got another ttr soon after.Dont ignore it like others have said, it can cause serious damage.

The link below is the same one I used on ebay

 

https://www.ebay.co.uk/itm/152827936389?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=XxuzchbcQYm&sssrc=4429486&ssuid=4cxXrX8RRme&var=&widget_ver=artemis&media=COPY



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