Tip: How to reduce engine noise.

[Junster]

Click the SBP link on the left. They have head stud kits. I'll be doing this mod tomarrow to see if that's what I'm hearing. Cause it sure sounds like the gears to me.

 

[cabinfever1977]

i put a hose on the end of my carb and ran it to a homemade airbox with filter,its a lot quieter now.

 

[EnFlaMEd]

I have just installed some cut up silicone hose joiner and stuck that inbetween my fins. It has definately made a difference. I wouldnt say that it has reduced the volume of noise as such but it has definately taken an element of it out making the engine sound smoother and less harsh.

 

[robpugl]

If you took a nice block of rubber and somehow attached it to a small engine covering just right amount of surface area to absorbed vibrations, a significant amount of noise will be reduced. I suggest finding a block of rubber at a well-supplied hardware store. Cut it (in about) .5” X 1” X 4” cut 3 or 4 strips cut spaces for your fins into the .5 sides. Cutting can be done with exacto blades and a little shaping with a soldering iron. Push strips into fins 3 or 4 sides of your engine so long side runs up down direction tighten with some tie around wire, metal strap or plastic police handcuffs (demonstrators from Seattle know what I’m talking about. There still will be plenty of surface area for cooling.
For more noise and vibration reduction on any engine setup try silicone. Pick up some calking silicone like they use for tubs and sinks. Sold in tubes. Shoot some in between everything metal making contact with anything metal…like in between where engine and bike frame gas tank clamp to frame. When silicon hardens is helps absorbs vibration therefore noise.

 

[Flapdoodle]

I am confident enough to share this now. I found the right side gear noise on my HT 80 very annoying. Every time I looked inside the grease had gotten slung off. My theory is anything that stays put of unknown lube properties is better than one guaranteed to come off in a few miles.

I cleaned the gears as best I could with a paintbrush and mineral spirits, then applied Bell-Ray's white chain lube after the mineral spirits evaporated. It was a bit quieter immediately.

Now after a few hundred miles there is virtually no gear noise, and the gear teeth look good; the faces have a polished look as opposed to the rough look it had when new. It is a guess, but perhaps the teeth have worn together for a better mesh.

 

[solitus3989]

I don't know how much spare rubber i have lying around...

But i recently used High Temp Copper RTV to remake the bottom gasket.

Do you think i could squirt a fair blob of that between a few of the fins?

(sorry if this image doesn't work, im at work where photobucket is blocked. gotta go by memory)

http://i87.photobucket.com/albums/k156/Solitus3989/SD530632.jpg

 

[Bryan Smith]

When Mounting my engine I wrapped plastic strips from a thick water bottle around the tubes at the motor mounts. it is solid but still absorbs vibration. I've heard that getting the rear mount flat on the seat post when installing the motor helps with vibration and noise. I did this and my engine has very little vibration issues.

Gluing a flat sheet of craft foam to the clutch cover is supposed to reduce noise also.

 

[DJEEPER]

Well, to revive an old thread... i went ahead and shoved some submarine grade insulating rubber (really dense) every other fin, two to each side.

I will see how well it does tomorrow!

 

[Just_Gasit]

Automotive vacuum hose workd great, just cut 1 inch lengths and stuffem in. I went with every other fin. They didn't take much effort to put in but none have fallen out. I did this on the motor before I ever ran it (from this thread) so I can't say how well it works other than my motor is pretty quiet over all.

 

[fourfeathers]

I am confident enough to share this now. I found the right side gear noise on my HT 80 very annoying. Every time I looked inside the grease had gotten slung off. My theory is anything that stays put of unknown lube properties is better than one guaranteed to come off in a few miles.

I cleaned the gears as best I could with a paintbrush and mineral spirits, then applied Bell-Ray's white chain lube after the mineral spirits evaporated. It was a bit quieter immediately.

Now after a few hundred miles there is virtually no gear noise, and the gear teeth look good; the faces have a polished look as opposed to the rough look it had when new. It is a guess, but perhaps the teeth have worn together for a better mesh.

I've had that annoying gear noise from the clutch cover for ages. Today I took a piece high density foam rubber about 10mm thick, cut it to shape and glued it to the underside of the clutch cover. Works a treat. I also use dry-lube ( powdered graphite ) on the gears. Nice and smooth sounding now. Am going to try the rubber between the fins trick now. I'd never thought of that. This web site never ceases to amaze me at the little tips you can pick up.

Ride-em MBs; ye ha!