Diaphragm Arm Spring

[Bob V 12]

Does anybody have a carburetor arm spring for a Tiny Tiger 300 that they would sell? Mine has one of the legs broken off.   Thanks.....

[Wallfish 724]

It's on it's way

[Bob V 12]

Hi John - The diaphragm spring arrived today along with the diaphragm and gasket you included. Thank you for that. I installed it and got the Tiny Tiger 300 running. The one you sent is working but it appeared to be worn at the two ends, where it cups and should rest on the diaphragm roller. One side barely rested on the top of the roller and the other side was slightly shorter, so it does not make contact with the roller. I made sure that the spring was in as far as it could go. Like I said, it is working, but I don't know for how long. With one end of the spring sitting on top of the roller and the other not on the roller, it makes the diaphragm arm slightly off center, so I don't know how long it will run like that. I was wondering if you have another diaphragm spring, in good shape, that I can buy from you? Don't get me wrong, I am grateful for the one you sent, but would like to have a good spare in case this one does not last. I am more than happy to buy it. I mailed you $20.00 for the spring, diaphragm and gasket that I received today and you should have it by the end of the week. 

 

Thanks again,

Bob

[Bob V 12]

Hi John - I mentioned that the two legs of the diaphragm arm spring were shorter than they should have been, one more than the other. Well, I found two small pieces in the envelope that you sent the spring in. The culprit was probably the high speed sorting machines that the USPS uses. They put a lot of pressure on the envelopes when running through the sorting process.

[Wallfish 724]

11 hours ago, Bob V said:

Hi John - I mentioned that the two legs of the diaphragm arm spring were shorter than they should have been, one more than the other. Well, I found two small pieces in the envelope that you sent the spring in. The culprit was probably the high speed sorting machines that the USPS uses. They put a lot of pressure on the envelopes when running through the sorting process.

Surprising that would break a spring. 

I pulled that one from one of my good carbs. I'd need to look around for another one if I even have one.

. A while back I was making my own out of spring material sheet because they are pretty scarce now. 

[Bob V 12]

Hi John - Don't worry about it. I thought maybe you had a surplus of them.  I will try making one from a feeler gauge. I have several laying around and will match up the tension and then cut it out and make the bends. I don't know if you have ever seen a video of the USPS letter sorting machines, but they have vertical rubber rollers that apply a lot of tension to the envelopes to keep them running at warp speed. It was not the whole spring that broke, just the very ends where they are cupped to rests on the diaphragm roller. That is what I found in the envelope. As I mentioned, it runs fine and may never be a problem, but it just kind of worries me that one of the legs does not sit on the diaphragm roller and that in turn makes the diaphragm arm sit a little bit off center.  I will let you know how I make out. 

 

Thanks,

Bob 

[Wallfish 724]

I have some blue tempered spring sheet metal .003" I can send you. I was making my own springs out of it and found that grinding the center out with a thin cut off wheel worked much better than trying to cut it out. Then cut the outside shape. Just don't grin hard to heat up the metal or it will loose it's spring properties. 

50" x 3" can make A LOT of springs.

 

[Bob V 12]

Hi John,

 

I made a spring out of a feeler gauge, but I have not installed it yet. I will try to get to it tomorrow or Saturday. If it does not work, I will take you up on your offer. 

 

Thanks,

Bob

[Bob V 12]

Hi John,

 

Well my feeler gauge experiment was a failure. The material probably has too much tension. It would not prime and would not run, so I assume it is putting too much pressure on the ball. If you can send me a piece of the material that you used, I would sure appreciate it. 

 

I don't know if you are a fan of Bring a Trailer, but I visit the site occasionally to look at all the vintage cars, motorcycles, mini  bikes and go kart of yesteryear. I saw this micro-power micro-bike. Is this the same type that you have or had? I posted a link below.

 

https://bringatrailer.com/listing/micro-power-micro-bike/

 

Thanks,

Bob

[Wallfish 724]

On 6/20/2026 at 2:22 PM, Bob V said:

Well my feeler gauge experiment was a failure. The material probably has too much tension. It would not prime and would not run, so I assume it is putting too much pressure on the ball. If you can send me a piece of the material that you used, I would sure appreciate it. 

 

I don't know if you are a fan of Bring a Trailer, but I visit the site occasionally to look at all the vintage cars, motorcycles, mini  bikes and go kart of yesteryear. I saw this micro-power micro-bike. Is this the same type that you have or had? I posted a link below.

I'll get a piece out to you

 

Yes that's the same but mine is a repop that I built a few years ago. $1500 + is too steep for little collectables.

Here's a link of the thread. 

 

[Bob V 12]

Thank you John...