TR5/TR250 TR-250 Vacuum advance module....

[DMShuman]

Looking for a TR-250 Vacuum advance (module?) See picture. Please contact me if you have one to sell or tell me I don't need it.

 

[DMShuman]

Ok it is a Vacuum control valve.

 

[PatGalvin]

DM
where is that part located? In the distributor? Just wondering.

Pat

 

[poolboy]

That actually functions vacuum breaker..that disables the vacuum retard module on the distributor under certain conditions.. Need it ? No you don't need to retard the ignition timing at idle at all. Let the engine idle and with the tip of your finger feel for suction and put a plug or cap the line at that point so the carbs won't be sucking air thereby disrupting the mixture.

 

[poolboy]

DM
where is that part located? In the distributor? Just wondering.

Pat

Attached in a bracket to the front carb so that the fast idle cam can control it as it sweeps upward when the choke is engaged.

 

[TR3driver]

I agree, not necessary unless you are into strict originality. The valve works to only apply vacuum to the retard unit when the throttle is fully closed (slow idle); but you can just cap off the vacuum line and reset the idle without the retard. Don't forget to use the "static" timing value from the book, though, not the "4 ATDC" value. The vacuum retard is what pulls the timing back from 10 or 12 BTDC (I forget which offhand) to 4 ATDC.