Vacuum advance??

[allred6]

Glad to have found you guys.
Losing power and not firing on all four cylinders. Some but not all of the time. Someone thought it was the vacuum advance.
What I have tried:
Re-routed around it - worked fine.
Routed back in - overheated.

[ratbyk]

Vacuum advance

allred6 I think that you are close to the problem but not quite. Go to service tips on the left side of the front page. Click on it, then scroll down to ignition. Continue scrolling until you hit "pick up wires". You found it. Read throughly, understand it then pull the ignition cover of the left side of the engine. Locate the pickup wires where they come off of the pickup coils. Pull on each wire as though you meant it. One or both will stretch abnormally long and take on an hour glass shape. You have found the problem. Follow the directions in the tip to make the repair. Take your time, do a good job of it. Don't want it failing again in the near future.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"

[xssiveone]

Re: Vacuum advance??

Originally posted by allred6
Glad to have found you guys.
Losing power and not firing on all four cylinders. Some but not all of the time. Someone thought it was the vacuum advance.
What I have tried:
Re-routed around it - worked fine.
Routed back in - overheated.

Re-routed around what?

The most common problem with the vacuum advance units is the wiring. It get's brittle and breaks. Stretch the wires out and pull gently on each end. If you see a point in the wire that looks like an hour glass, the wire is broken and needs to be replaced. Test lead wire like the kind used on multi-meter leads has been used with great success due to it's great flexibility. Ken Talbot has a nice page on this repair: Pickup coil fix

To check the vacuum canister, compress the vacuum diaphram (push the piston in) and then hold your finger over the vacuum connection on it. If the piston stays in, then the diaphram is good.

Also, one other problem is dirt and corrosion on the mechanical linkages. Clean all pivot points and apply some light grease.