MOPED ARMY

Figured it out. I was able to make a cheap RFI shield (two layers of tin foil....) and the Mp3 player worked right next to the mopeds engine.. I should be able to get the AMP to work by doing the same thing.

When I took the tin-foil off the Mp3 player with the moped running, it stopped instantly... when I put the tinfoil between it and the moped, it worked fine.

I am a little concerned about the extra heat the tin foil might cause... I may line the whole pannier with foil instead of just insulating the AMP.

I'm glad-- I've been trying to figure this out for about 2 weeks. I decided to research the EMI shielding industry-- the professionals use foil attached to a polymer in layers-- this is the most common way, because it addresses the "Victim" of the EMI without addressing the cause. it would be impossible to wrap my whole moped engine in foil to stop EMI/EMR output, so I need to block the "victim" (amp) from the EMI.

Why is this post important to people who don't have a stereo? Someday you might try to listen to a walkman on your ped, and unless you remember the tin-foil EMI shield, you may not be able to have music-- the gears will turn but the output will be disrupted.

I'll post more when I have the new 80watt amp insulated and working.

-Wayne

That's a darn good idea-- ! I don't have any of those bags 'cept a little one some memory came in... Thanks for the input-!

I think I fixed it, but I like the idea of a bag better than tin foil.

I was also thinking about that metal duct tape-- that might be thicker than the tin foil, so would need less layers--

Thanks!

Brandon, tell me more--! I was unaware, and would like to pursue that option!

Wayne,

I had a similar problem with my weedeater years ago. I couldn't get my walkman to work without serious distortion when it was running. I found that aluminium works best for EMI shielding. I built a little box that I clipped to my belt, that the walkman could sit in. It worked like a dream. If you can find the precise source of the EMI, you could either build a shield around it or at least between it and the amp. You have make sure though, that the shield is grounded to work properly. You can even paint it to match whatever you want. DON"T use the mylar bags from computer parts. They don't protect well from EMI. Just static. And they are flammable too!!!! As for your spark plug boot, you would be better served with a suppression cable as well. I think the real thing to figure out is, is your problem caused by EMI or RFI. Both can play havoc with electronics but each has different solutions.

Richard

here's more info-- Thanks for the help!

Just to make sure I mentioned this; The stereo amp and air horn are powered by a seperate battery in the pannier bag, not hooked to the moped electrical system at all-- I did try grounding the amp to the moped but the interference got worse.

I haven't tried to build an aluminum box yet, tried foil, some success (at least a signal...) but not quality sound at all.

The moped needs to be about 4 feet away and the stereo will play fine, come in close and it crackles out.

What pisses me off is that the other amp (road gear brand name) was a 35$ Wal-Mart special, and it had no trouble, the new amp, same company same price range, new model is totally affected. I wish I'd saved the old one to look inside and see what was different.....Maybe I could have swapped parts.

I'm going out soon to get a new amp, but I don't know what to look for as far as shielding or features to prevent this. I tried an RCA ground-loop isolater, knew it wasn't going to help, and it didn't. I had to try, though.

Ree: I've got a Tomos Targa, 2000 model, with Bi-Turbo, no piston kit.

Jon: For real? 1000 watt amp on a moped? wow I am humbled-- would love to get some info on your setup, please! for example, where do you get the extra power?? I gotta know more!!

Richard: Will I need to build a box, or can I screen the EM/RF with a partial shield facing the engine?

How thick would the screen need to be? I was also told to use copper-- Tin foil was a big pain in the ass. I've got a bunch of photos of my moped here on the army site, so I'll clip one to one of the next posts.

Thanks again for all your help--!!!

I got some aluminium sheet used for autobody repair (it'll be in the same section of a good hardware store, something like Pep Boys. You would want to get the sheet at least in between the EM field and your amp, so weather you would need to build a box or not would depend on just where you are placing the amp, and where the EMI is coming from. Have you checked into the placement of your cables as well. It wouldn't do any good to shield your amp if the signal cables run through the EM field as well. If they do, you'll need to shield them as well. I think first thing I would do is try to figure out the specific source of the interference and see if it could be corrected with a new resitor plug or plug wire or something along those lines. It would be WAY easier on your soul to do a plug change than to go through all this trouble to build custom shielding.

Good luck.

Richard

Okay--! I think I might have it.

My Tomos uses NGKbp4hs plugs. The coresponding NGK is a BPR4hs

Like you all suggested, these plugs are designed to produce less interference/noise than the standard plugs...

2.19 a pop. I'd like to find a Bosch Platinum with the same feature, as I've heard the worst about NGK (jap) in a Euro bike.

Thanks again. Stuck at work now, but I'll try it out after I get out. If this works, it will be grand, because I can use an MP3 player instead of the cassette deck, and will lose weight and get better sound.

I'll keep ya updated-- thansk again!!

(where did the dude with the 1000w amp go? I'd like to get more info!! Sweet amp, for sure...wondering how you power it...!)

-Wayne-

use a capasator between the sparkplug and the coil. edmund SCI has them for like 10 for $1. this should damper the electromagnetic field. its used in cars all the time and it does a fine job. i dont know of any shield what will work (mostly becaue ive never heard of or tryed it) but i dont know, it could work. email me for a wireing diagram.