How can I make my bike quieter?

[Nick]

The plain muffler is from a GG MC250

[flybars]

Here's what I've found out about the spray-on stuff for noise reduction for your aluminum skidplates. Talked to the tech at Bondo Corp. and he said I need to get " paintable rubber undercoating". It's heat resistant and U can paint it too. His brand is "Marhyde 4311". They checked for me, and Wash. State has none. I finally found some at Autozone. "Dupl-color" has two; the "Standard" and the "professional". "3-M" also has a "paintable rubber undercoating".
Directions are important: "Clean surface with acetone and scuff with 180 grit sandpaper". Two coats ought to do it. I think U can paint it any color if U like, with engine paint if I heard him wright. Better check though.
All the other stuff including bedliner's have an asphalt base and runs once it heat's up. I have'nt had a chance to pick some up yet, but plan on it. Thanks, Bob

[flybars]

Finally got the skidplate sprayed with the Dupli-Color paintable rubber undercoating. I used 100 grit sandpaper because the 180 didn't hardly scuff it at all. Then cleaned it up with acetone and used half a spray can. It said to apply when the temp. is 70 degrees or more. It looks good and is black. I only sprayed the in side of skidplate and all the brackets which clamp to the frame peices.
It took quite a bit of the noise out. But not all. It's alot better than before and I can live with a little noise. I wonder if I used the whole can, if it would be quieter?

[d2w]

Did you ever try simply to fill the void between the plate and the engine with, say, Moose-brand skid plate foam?

That method also has the benefit of reducing the amount of mud/dirt/debris that accumulates between the plate and the engine.

Dale

[flybars]

I've heard of that but have'nt tried. I wouldn't want to remove my skidplate very often with the foam. I've also read that U can slit radiator hose and wrap frame tubes where skidplate makes contact. Also my new B&B skidplate for my FSE came with black foam cushioning taped to it where it meets all frame parts.

[gtsnowcrack]

UPDATE: The power valve on my bike was gunked up to the point that it was stuck open. This resulted in little bottom end and awesome top end. Also REALLY LOUD. Cleaned up the PV, polished the ports a bit and put it all back together. Runs a lot quieter on this first ride and awesome bottom end! It's like I got a new bike with the same plastic! Too bad the plastic is scratched

I'm going to take the pipes I got from Nick at Cycle Pro and test them with a dB meter as soon as I can. More later.

[Magellan]

I think that Dynamat might be worht a try (and I think I'll try it) on the skid plate.

It's self-adhesive, and I have some question as to how well the adhesive will hold up, but A small amount won't cost much. I'll try the stuff made for uner the hood.

I wrapped my frame rails with some old inner tube rubber before mounting my skid plate. I did it to protect the frame, but it probably has helped with the sound.

I picked up a Euro silencer from JeffD, and will try that out once I get an SA to go with it.

[SpeedyManiac]

FYI, I had my bike 2001 EC200 sound tested this weekend. I have the stock euro-spec silencer and the messico (GasGas) pipe. Other mods are the MC ignition/flywheel, LTR powervalve cover, aluminum skid plate with slightly loose mounts and carbon fibre pipe guard. I tested at 85.8dBA. My buddy on a KTM250XC (stock) tested at 85.0dBA. My other buddy on a KTM450XC (stock) tested at 101dBA.