Vibration causing gas tanks to break?

[Etaub1]

Yard machine 4.5 HP
Briggs Stratton engine

Hi guys...

Two gas tanks have broken off underneath the loop thru which the large screw passes and attaches to the Lawnmower. Might it be the vibration of the mower? I ratchet them in pretty tight.

Any suggestions how to reduce the vibration or other reasons for the gas tanks to break ?

Thanks.
Ed

 

[Rivets]

Two things cause vibrations on a mower. One, blade bent or out of balance. Two, bent crankshaft. I would check both, especially if something was hit in the passed. There is a third possibility, that would be a partially sheared flywheel key, but then the engine would not run very well.

 

[reynoldston]

You might want to try some rubber under the loops?

 

[motoman]

I guess what is meant is what causes "undue" vibration on a tractor. The one I have ( not unlike others?) has an inherently unbalanced V motor ,solid steel motor mounts, no suspension, and stubby wheel base to bounce over rutted ground . I guess it's what a person is used to.

 

[Etaub1]

... bent crankshaft.

Rivets...thanks for the reply.

If I remove the blade, does the crankshaft just lift out? Or do I need a crankshaft puller for the top of the mower? Hope not, 'cause I don't own the tool.

Ed

 

[Etaub1]

You might want to try some rubber under the loops?

Thanks, Reynold. So... Create my own thing-a-majig and line the loop? Don't know how much room I have to work with.

 

[Etaub1]

I guess what is meant is what causes "undue" vibration on a tractor. The one I have ( not unlike others?) has an inherently unbalanced V motor ,solid steel motor mounts, no suspension, and stubby wheel base to bounce over rutted ground . I guess it's what a person is used to.

But have your gas tanks broken off? If mine hadn't, it wouldn't bother me either.

 

[Rivets]

To check the crankshaft, first remove the spark plug. Tip the mower on it's side, carb up. Remove blade. Have someone pull the starter rope while you watch the end of the crankshaft. If it wobbles, it is bent and needs to be replaced. To check the blade I recommend you take it to a good repair shop and have them check, sharpen and balamce it. That should cost you no more than $7.50. Didn't think of it before, but the blade may need to be replaced, due to wear.

 

[reynoldston]

The rubber under the tank straps are just a cheap try fix. If it has a bent crankshaft which would be a major repair what I would try frist is a big hammer and see if you could bend it back. As far as a mower blade why not a new one, less then 20 dollars a cheap fix.

 

[Etaub1]

To check the crankshaft, first remove the spark plug. Tip the mower on it's side, carb up. Remove blade. Have someone pull the starter rope while you watch the end of the crankshaft. If it wobbles, it is bent and needs to be replaced. To check the blade I recommend you take it to a good repair shop and have them check, sharpen and balance it. That should cost you no more than $7.50. Didn't think of it before, but the blade may need to be replaced, due to wear.

Thanks for the instructions.

The blade is only a couple years old, but honestly it has nicked the underside of the mower in the past. (Dont ask me how.) Maybe it got damaged and is the cause of the vibration?