Speed servo measurement please

[thethee]

Been working on getting my speed control back up and running and I have found the issue with my servo unit. The vacuum inlet on this is actually a press in fit. Unfortunately, at one point mine came out of the housing. As there isn't a clear depth indicator I need some help for finding the correct depth for this one. If it's pushed in to far, the speed control won't lock in a speed setting. If it's not pushed in enough the speed control will keep accelerating.

Is there anyone with a formal style speed servo that can get me an accurate measurement?

 

[CBODY67]

Might there be another drilled/cast vac passage which the tube blocks off at some level of insertion?

Just curious,
CBODY67

 

[thethee]

Kind of.

On the inside is a brass plate that blocks off the opening off the vacuum inlet tube. If roadspeed gets higher than the set speed, the brass moves to the right closing off vacuum to the unit which releases pull on the throttle in turn reducing speed. So the depth of the vacuum inlet seems critical to it working right.

I was planning on doing a how it works thread once I figure this last thing out.

 

[Welder guy]

21.30mm I just happen to have 4 of them on my shelf.

 

[thethee]

Awesome!! Thanks for that. Can't wait for the weather to clear up to try this out.

 

[thethee]

Took me a few tries but I got it at 21.25mm and I think it's close enough. We'll see in a couple weeks if that did the trick.