Tomos a55 stuttering, and clanking a little? (sound file)

Tomos a55 is stuttering and clanking at idle. I have an airsal 70cc kit, biturbo exhaust.

I just checked the timing about 5 minutes ago and it is dead on. It sounds like there's metal hitting metal, but this might be me mis-hearing things. the P.O. says that this clanking has been going on for a long time, but hasn't affected anything. I opened up the top end a few days ago, and it looks great. Things look like they're working just as they are supposed to, nothing looks bent or broken. It will do this at idle, and occasionally cut out and die but not always. SOmetimes it seems that it actually stopes for a sec, and then the engine recatches and it keeps going. It seems to go away at high speeds...

What could cause something like this? has anyone ever experienced anything like this before?

I am trying to attach a sound file, I hope it works... for some reason it doesn't work on my itunes but works with vlc, windows media, etc. let me know if it doesn't work!

Re: Tomos a55 stuttering, and clanking a little? (sound file)

Steve Perkio /

Wow, good recording and thanks for taking the time to provide it for review.

I'm thinking that it's an electrical ignition issue, but there are many guys with a better ear than I have.

Hopefully they will chime in soon.

Perk

Re: Tomos a55 stuttering, and clanking a little? (sound file)

I had the same issue.

I realized that the bike was jumping out of time because the woodruff slot in the flywheel was not stripped but gouged slightly and the woodruff pin in the crank is also bent slightly. So basically the flywheel had play and was jumping out of time, this is what caused that fucked up noise.

I timed the ignition and slammed the hell out of the flywheel making damn sure it was on the crank taper. Then tightened the flywheel nut on without stressing the flywheel against the woodruff pin on the crank. so far so good. no more weird noise. But it prolly wont last long.

This happend because I was using a piston stop to get the flywheel off and tighten it back. fucked my shit up.

Re: Tomos a55 stuttering, and clanking a little? (sound file)

Marcel Lowrie /

Sounds to me like a misfire but I don't know all that much so I could be wrong. Just sounds like it is not firing at all. I don't really hear metallic noise.

Re: Tomos a55 stuttering, and clanking a little? (sound file)

definitely not a metallic noise and its not consistant.

Re: Tomos a55 stuttering, and clanking a little? (sound file)

Marcel Lowrie /

Yeah like 7 seconds in it sounds like a misfire, like it wants to die. The rest are kinda missed beats...idk. I guess it's a misfire thing. Ignition related I say. Again, don't know much tho. Hope someone else chimes in.

Change the plug and boot for a known good set I say. Cheap and could be it. Try new gas too. Those are quick cheap fixes that could be it. Other then those the fixes are more complicated and expensive.

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