Motor vibration throught Kart ***

[T-man]

I dont suppose anyone one knows how to dampen the vibration that comes from a motor? I have an old yerfdog (I think) and when I have the motor on it (now on the tumbler) I can only drive it about 2 hrs before my a$$ goes numb. So I was woundering if there was a way to keep the vibration of the engine from transfering down throw the whole cart. that go kart that I have says "ratler" on it like the snake, does this sound familier to anyone??

 

[jmadden91]

Lol padded seat?

 

[r_chez_08]

rubber mounts? not sure if these help, and help the engine.

 

[Kenny_McCormic]

Get a better engine? That or a better seat.

 

[Rickracer]

A padded seat is your bet bet, any rubber in the mountings will allow movement that will disturb the relationship of the sprockets and chain.

 

[anderkart]

2 hours on a kart... Jeeze, my kart vibrates so bad I'd have to stop and re-tighten all the bolts that aren't safety wired every half hour or so.

 

[whitepower]

Ruber mounts Like on generators the engine is supsended by rubber mount things i bet u can make some if u get some pics or just go to ur homedepo or candian tire and look at some gennys buy 1 take it home rip off the mounts put it back together and return it

 

[nerfo]

I would think rubber mounting the engine might be a bad idea because, just like Rickracer said, allowing the engine to move will constantly change the alignment between the engine sprocket on the clutch and the driven sprocket. Under acceleration, the engine would have a tendancy to twist. (with the hood of your car popped, have someone put the transmission in drive and watch just how much that engine moves!) Of course, if you do try something and it works, be sure to share it with us. Or find a way to put rubber isolators under the seat... who cares if that wiggles a little?!

 

[GoKartGuru]

Yes, the engines in particular those that are above 6 hp are vibration maniacs. I had an 8 hp briggs and dared not take it above 3600 before it vibrated like crazy. The balancing inside the motors is not terrific. One way to keep the vibration down is to look into your engine rpms. Is the engine screaming, or is just the thunderous pulses from the power stroke.

Cushion mounts help, but beware it will mess up your drive train. If you have the engine on an independant mount system, then the main hinge points can be isolated with rubber mounts. This will avoid the headache of mounting your engine on rubber mounts or spring mounts (like the paint can shakers you see at Home Depot).

The idea is to isolate the drive system/engine fromt he passenger compartment. I have seen that your tumbler kart seems to have this suspension system, so I would think it would be ideal to just isolate the suspension areas with rubber mounts similar to those cars use on their suspension components. (Remember most cars have rubber mounts on the bodies too...isolating the passenger compartment)

And finally...not to be overwinded... isolate your steering system with rubber mounts so the steering doesnt shake to death, and isolate the seat with rubber mounts, this will help keep the vibration down.

And yes one last thing, make sure your engine is tuned optimally and not running rich. Typically a rich running engine will have tons of torque but will have the side effect of vibrating alot. You can tell if it is running too rich if it will not run up in the rpm range without blowing black smoke and running rough.

GKG

 

[T-man]

Ya I was thinking of the rubber idea but then it dawned on me that skateboards have a spacer , nylon plate , that helps in vibration and distanceing the wheels from the board. Now I also know that a person can get differant grades of nylon, dence and soft. Now I know that I wont be able to get all of it gon but some is better then nothing. So if I could find a place where I could get say a 5/16 thick piece of soft nylon sheet that I could put under the engine ... that might work....maybe what do you guys think??

 

[brendonv]

Dont put rubber under the engine. If the engine is hard mounted to the frame then it cant vibrate.

 

[Rickracer]

I still say pad the seat , or rubber mount IT, nylon mounts for the steering components, as someone else mentioned above, would help as well.

 

[cooldude]

Vibration

Hey guys been reading your posts, I also have a vibration issue. Built up a 6.5 honda clone. Talk about a shaker. This thing blurs your site. lol. I checked the balance on the crank and it was out. So I balanced it with a formula I found online. Then balanced the cam. It was also out. That did help some. But I`m not happy yet. I am now tinkering with some camaro lower control arm bushings and designing a custom mount. It will be some what stiff, But should help. Some is better than non. Just want to get it so I can ride this thing for a while without going numb. I will post in a few days and let you know how its working. Well I built my mount and it works great. I used eurothane bushings that allow no movement yet isolate the engine. The chain stays inline. Works very well. I plan on doing a bit more to remove a little more. About 50% of the vibration is now gone.

 

[jpowers]

rubber mounts are the way to go. they use it on triumph motor cycles to reduce the riding vibration

 

[fowler]

motor bikes engine are mounted differantly

i like the idea of nylon bushings

 

[T-man]

Ya , Im not sure if I like the idea of rubber as a plate under the engine, just because the moment the torque of the engine engages then the thickness on the plate will change. Then the distance of the chain changes ...and then "vroooommmm" it falls off.
I think nylon would be the way to go.

 

[CriticalMass]

Somebody in another thread said to mount the seat on car valve springs.

I would be against mounting the engine on anything due to chain issues.

 

[redsox985]

I slipped rubber toilet bowl washers under mine. They're each about 1/8" thick and give just a bit of cushion so that, when paired with a foam seat, the ride is pretty smooth.

 

[Bluethunder3320]

I cant imagine it changes chain tension a great deal. Especially if the sprocket is underneath the engine.

Using rubber washers or gromets cant cost alot... Give it a try?

 

[Miles]

the thinner the rubber cushion, the less it'l be able to twist, so I'd go with a fairly thin one. also, if it did twist a bit, you could always use an idler sprocket with an arm attached to a large spring as a nice chain tensioner