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Old 11-27-2009, 12:43 PM   #1
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Default flywheel slipping

I have a v-spec with 8 gallons on it. At the last race it felt like the power just left the engine. My first thought was that it lost all of it's compression. That night I remove the flywheel from the engine and the collet looked as if it was spinning on the crank. There was also brass shavings behind the flywheel. A week before I did have the flywheel off so I can inspect the front bearings and I did have trouble getting the flywheel nut tightened. During the first install of the flywheel before the engine was broke-in there was plenty of resistance to tighten the nut down. On this second install a lot of the compression was gone and I was not able to get it as tight. I had to put a tie wrap in the cylinder to keep it from turning over.

So my question is... has anyone had a problem with a flywheel slipping on the crank? If so what did the engine sound/feel like? And finally how did you tighten the nut down?
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Old 11-27-2009, 01:13 PM   #2
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Channal locks and rag, hold the flywhell with the locks and rag,blue locktite on the crank threads and tighten the hell out of it. Should be good to go.
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Old 11-27-2009, 01:22 PM   #3
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a washer behind the collet will help too, the ofna clutchbell shim kit comes with a couple of them, the brass ones. tighten the nut down as hard as you can, then take the nut off and locktite it in tight again. should last as long as the flywheel. also, try to use different flywheels on separate motors, taking the flywheel on and off introduces slipping. have fun!
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Old 11-27-2009, 01:27 PM   #4
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there is a plastic tool that you can put through the back plate to lock the crank and rod from spinning while you tighten up the nut
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Old 11-27-2009, 02:30 PM   #5
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I had the same problem as you had at the beginning of the season. It kind felt like I was running teflon shoes at first then felt like it lost all its power. Sounded exactly the same as usual. I replaced the collet and switched to my spare flywheel. Never had a problem after that. I like a dumby forgot to lok-tite the flywheel nut, everything got loose, and I am sure that what caused the brass shavings wich I as well had. I also had to do the zip-tie thing to get the nut off. I have 7 gallon on my engine after that happened and it already had 2 gallons on it prior. (engine was as well a v-spec)
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Old 11-27-2009, 03:00 PM   #6
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Once the flywheel slips for the first time and digs into the collet its over and it will start to slowly get worse.

The starter box is what I found that eats them faster then just normal running.
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Old 11-28-2009, 09:52 AM   #7
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+1 on channel locks, I like the tamiya ones with the Teflon on them, and blue loctite. Then I use a deep socked and 1/4 craftsman handle, no ratchet needed to tighten the nut down until it is as tight as I can get it. Never had a prob using this tech and I haven't used any shims behind the collet.
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Old 11-28-2009, 10:41 AM   #8
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I've never been able to tighten a flywheel nut without locking the piston in place, yet I have seen it done.
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Old 11-28-2009, 03:22 PM   #9
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i have a makita 14.4 electric impact i use. I put medium strength loctight on the nut, then hold the flywheel by hand and impact it on. works great.
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Old 11-28-2009, 07:27 PM   #10
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The only piston stop I would use is the one that attaches to the crank. But who wants to remove the backplate to change a flywheel. Just use channel locks and a wheel wrench. Only reason to use a piston stop is if the flywheel will not lock on the collet like the OP mentioned.
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Old 11-28-2009, 07:51 PM   #11
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how about the flywheel locking tool?

if you ever have to lock the crank , use a piece of plastic such as tooth brush and insert it into crank opening after you have removed the carb .

http://www.amainhobbies.com/product_...tch-Multi-Tool ?

on a losi use an adjustable wrench on the outside where the pins thread into and make sure you use the right collet
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Old 11-28-2009, 08:33 PM   #12
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I use a flywheel locking tool. If the collet is correct for the flywheel and not worn from slippage, you will not be able to spin it when tightening with the flywheel locked. And you will not need to lock the crank to remove the clutch nut. Just clean surfaces with brake cleaner first.
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Old 11-28-2009, 08:35 PM   #13
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all u need is a rag and loosen the glow plug and a pair of pilers and hold it tight and use the losi wrech with the 5 sockets on it ,its easier when theres less compression too
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