[evan_j]

So, new member posting after lurking and reading a lot of great info,

So, after letting it sit for almost 18 years in the barn, I bit the bullet and pulled the carbs off my 82 CM450e for a thorough cleaning and rebuild. All was going well until unknown to me something (or someone) knocked one of the "vacuum piston springs" off the bench and on to the floor (#15 on the image at the link below). One step backwards from the bench and i now have a spring that isn't quite the dimension it used to be. From my searching finding a new one of these springs seems to be a no go. Anyone have a good source for a replacement or know of an alternate model bike that uses the same spring? I have found some on ebay that are close, but none yet that seem to be the right thing. Any suggestions?

Thanks,
Evan

https://www.partzilla.com/catalog/honda/motorcycle/1982/cm450e-a/carburetor

 

[Crashoverride]

https://www.ebay.com/b/Motorcycle-Carburetors-Parts-for-Honda-CM450C/177773/bn_21416434

 

[80cb400t]

This might work, you could ask the seller for measurements for more confidence

https://www.ebay.com/itm/82-HONDA-C...OTTLE-VALVE-VACUUM-PISTON-SPRING/182293732530

 

[longdistancerider]

Al the VB22 springs are the same, VB21 and 24 are different.
PM your address so I can get one in the mail to you

 

[BrianHull]

What is the length of this spring at rest? I would like to check mine.

 

[longdistancerider]

What is the length of this spring at rest? I would like to check mine.

Of course I read this right after I shipped the spring. Maybe Evan can get you the number

 

[evan_j]

What is the length of this spring at rest? I would like to check mine.

Measuring my good spring, the springs from mine look to be right at 4 1/8 at rest, maybe 4 3/16.

 

[BrianHull]

Thanks! I remember having one spring longer then the other when I rebuilt my carb. I just adjusted them to the same length but I never knew the actual factory length. Also, if your finding it hard to find a particular spring, I would suggest looking at Mcmaster carr and ordering the diameter spring steel you need and bending it around some round tubing at the size you need. I have done this in the past when I need a specific spring that's hard to buy in stores. Use Hook's law to calculate your distances and forces and you can make about any spring you need for $10 us dollars or so.

 

[evan_j]

Of course I read this right after I shipped the spring. Maybe Evan can get you the number

Thanks again Jim for the spring.

Odd fact I found when it arrived. Apparently, even thought my carbs are VB22, they have what I believe are VB21 springs. My original spring is on the left, and the VB22 spring you sent me is on the right. I'm assuming the bike was assembled this way when new, as I am the second owner and the first owner didn't do anything to the bike.



At this point I re-shaped the squashed original spring as well as I could wrapping it around a dowel and used it to get the bike running. It certainly isn't perfect, but i wasn't sure how mixing VB21 & VB22 springs would work.

Thanks Brian for the idea of making springs, I hadn't thought of that. I'd looked at springs on McMaster Carr, but not spring making material