2 stroke stealth mods?

[sactownie]

Hi, I am currently acquiring the parts for my MB. I have the engine kit on the way to me but I am not going to install it until I get the SBP shifter kit. I want to build mine as stealth as possible which to me means quiet exhaust, fuel tank mounted any place other then the top bar and possibly a side cover formed out of sheet aluminum to cover both sides of the engine.
Its all going on a 99 marin muirwoods mountain bike so I just want it to look like a mountain bike.
Anyone here done any stealth mods to give me any more ideas for my build?

 

[professor]

As you will find, the intake roar needs a silencing box along with a better muffler (I don't have a 2 stroke but I read the "Poo po " muffler is quiet.

Quieting the gears in the engine - some guys glue cardboard or a mouse pad onto the inside of the gear cover.

I have my gastank behind the seat on a rack ,and works fine until about a quarter tank. Higher would be better. Having no motorcycle style tank on the bar goes a long way to keeping it looking like a bicycle. I used the tank off the HF engine I am using, but any tank will do.

Pedaling, good helmet, safety vest, gloves, glasses and sane riding all equate not attracting undue attention and thus, are stealth.

 

[MotorBicycleRacing]

Hi, I am currently acquiring the parts for my MB. I have the engine kit on the way to me but I am not going to install it until I get the SBP shifter kit. I want to build mine as stealth as possible which to me means quiet exhaust, fuel tank mounted any place other then the top bar and possibly a side cover formed out of sheet aluminum to cover both sides of the engine.
Its all going on a 99 marin muirwoods mountain bike so I just want it to look like a mountain bike.
Anyone here done any stealth mods to give me any more ideas for my build?

Why do you want to be stealthy?
Do you have a drivers license?

Motorized bicycles are legal in California.

 

[sactownie]

I prefer to be able to ride without people gawking at me and my neighbors not being able to hear me every time I leave.

 

[grinningremlin]

First part of stealth, rack-mount, if I don't point out my engine nobody seems to notice (when not running).Since you're going with frame-mount, that ship has sailed.The little cigar silencers can be used in line, two hooked up with the hi-temp silicone tubing would take care of most of the exhaust.Next is your intake, if you can figure out a way to make the airflow do a right angle it really cuts the noise.I put a ADA juice-box on my Tanaka pf-4000 and it cut intake noise 20%.So a velocity stack on your intake, then a radiator hose for your right angle, then something to hook the air-filter to.There's a pic on the forum, that shows a velocity stack hooked to a hose then a plastic electrical (4S??) box with a hole cut at a right angle, and the air-filter was rigged to that.
I'm more worried about my ears, and not having to wear plugs than making people mad.
Good luck, GG

 

[sactownie]

where do you get the silencers from or is there a brand I can search for? sounds kind of like the nitro r/c cars I used to have, the exhaust pipes connected with silicon tubing.

 

[Deleted member 12676]

I have an "Torque Pipe" expansion chamber with a "belly stinger" and my Stealth Silencer. It is amazing how quiet it is.

 

[grinningremlin]

where do you get the silencers from or is there a brand I can search for? sounds kind of like the nitro r/c cars I used to have, the exhaust pipes connected with silicon tubing.

Here's one supplier,http://www.davesmotors.com/s.nl/it.A/id.4389/.f
I've searched trying to find the company I bought mine from, as it came with 2ft. of tubing (no luck).Make sure it this type tubing (reinforced-braided), the high temp stuff without likes to kink on any bending.If you're good with your hands (metalwork, sheetmetal manipulation-cutting) I'd just buy a few feet of tubing and make my own silencer, simple concept and VERY effective.Ebay has a few on occasion.
Goped suppliers always have some neat crossover stuff for us.
GG

 

[sactownie]

Well heres what i have experienced incase anyone else wants to know the same question I had , I built my bike and used all the tricks to quiet it down including using a shifter kit and mounted the fuel tank in a bag in the rear rack but the only way to make the bike completely stealth that I have found is to cut the motor and start peddling. It works everytime!

 

[Fabian]

Exhaust noise (from a standard exhaust system) can be significantly reduced by adding two and a half feet of (13mm internal diameter) high temperature, chemical resistant, clear silicone tubing.

The tubing on my bike is 6 months old and it's still holding up well to the 400+ degrees Celsius (752 Fahrenheit) exhaust temperatures, with EGT spikes up to 480 degrees Celsius (896 Fahrenheit), even though the silicone hose has since discoloured to a light brown shade from the time that this photo was taken.