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TR6 Timing Problems ?

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rmbobcat

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Dear fellow members
Im driving a 1973 TR6 with the PERTRONIX Ignitor.
I’m getting a slight backfire in the carb around 3000RPM.Tried adjusting the timing ( No luck) Next checked the vacuum coming off the carbs 18 to 20 Hg. Next sent pressureinto the vacuum advance unit on the distributor hoping to see the advance platemove (Like in the moss video ) I couldn’t even get air pass the diaphragmVery strange. If I have to remove the distributor for service whats I correct way to remove &put back. Thanks for any help with my problem. Bobby McDonald/ Enfield CT
 
Bobby, I may stand corrected but I think the vacuum is a retard not advance. The advance is controlled by springs and weights under the plate.
If you are going to take out the distributor, get it pointed to #1, loosen the clamp nut and ease off the two nuts that hold the plate at the bottom of the distributor, If you can clean a spot to mark the housing that would be good. When you lift it up it will turn as it comes out of the gears on the bottom of the shaft. Now, at the bottom of the shaft is a slot that fits over the drive shaft of the oil pump, don't move that in the bottom of the hole. Take note of the position of the rotor button pointed at #1 before removal and when you pull it out were the turn ends up, that is the position you need to start when reinstalling, it should turn right into place.

Wayne

PS, your back fire may be a valve or adjustment.
 
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That's a retard module...not an Advance and it works by vacuum from the nipple on the bottom of the rear carb.
So suck on the retard module's nipple and if it's working the points plate will rotate in a counterclockwise direction.
............................................................................................
But I don't think the retard working or not is your problem.
I would check the carb diaphragms, real closely, and look for splits or tears.
.............................................
As far as removing the distributor, there is a single 7/16" bolt that is vertical and it holds the distributor clamp attached to the engine. Remove that bolt. THEN once the distributor cap or just the spark plug wires removed and the black and red wires from the Pertronix disconnected from the coil, the distributor along with the distributor clamp can be lifted out.
That bolt that goes here:

Then you can lift this out:

Doing it this way, replacement is not a problem because of the offset you see in this picture:

It only goes back one way and if you do not loosen the clamp around the distributor itself and rotate the distributor, the ignition timing will not change any more than the amount of space in the clamp that surrounds the bolt you removed.
Just rotate the rotor, until the distributor shaft lines up with the slot in the drive gear and drops in. Then, you are back where you started...as long as you did not loosen the clamp from around the distributor.
 
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Im driving a 1973 TR6 with the PERTRONIX Ignitor.
Click to expand...

which pertronix model are you using?
i had similar issues with a new pertronix ignitor/flamethrower III system on my 3.

after trying everything else I could think of, I replaced the new flamethrower III hot coil with a flamethrower II ( also tried my old Lucas sport coil successfully) & the problem went away.

Guy
 
Wayne & Poolboy Thanks so much for the info. I did try to use suctions on the vacuum unit and I was able to pull air through without the points moving ( hole in the rubber diaphragm ? ) didn't check the diaphragm in the carbs yet . what do you guys think of The Moss 560-159 vacuum advance conversion for my 73 TR6 ? Sounds like good to me. I'm jealous my driving season is coming to an end and you still have mild weather :encouragement: Thanks again Bobby
 
A lot of us don't use the retard feature. I say cap the nipple on the bottom of your carb and forget about it.
As far as converting the retard to an advance with that replacement module..I thought about it, but I don't think I will.
About the only true advantage is an increase in gas mileage for as long as you can hold a steady throttle.
Under any other throttle positions, it doesn't really activate to any meaningful degree.
How many miles driven under those conditions will it require to even pay for the module and what percent of your driving is at a steady throttle ?
 
I installed the BVU advance unit. There's a lot of play in the oval single bolt opening as shown in Poolboy's first picture above.

I measured this from the spark plug socket on #6. Makes it easy to get exactly the same position on reinstallation:

screenshot.2408.jpg
 
poolboy said:
A lot of us don't use the retard feature. I say cap the nipple on the bottom of your carb and forget about it.
As far as converting the retard to an advance with that replacement module..I thought about it, but I don't think I will.
About the only true advantage is an increase in gas mileage for as long as you can hold a steady throttle.
Under any other throttle positions, it doesn't really activate to any meaningful degree.
How many miles driven under those conditions will it require to even pay for the module and what percent of your driving is at a steady throttle ?
Click to expand...

I noticed that this topic has been revived.
That was nearly 5 years ago that I made that post and FWIW I changed my mind and had the Advance module installed maybe a year or so after I wrote that....I don't see it as a performance enhancement and I guess I missed a couple of opportunities to check the gas mileage on some extended Interstate travel.
Anyway, it's on there now.
 
I like to update an older thread when I have something new to contribute.

Will be getting my distributor redone by BVU in the near future and will report back here on any performance improvement. He says many customers are extremely happy with the performance improvement. They recurve it with new springs and overhaul everything like new.
 
I was definitly happy with the noticeable difference by having my distributors recurved..they needed it and those procedures were actually performed by Jeff Schlemmer of Adavnced Distributors.
I'd say if there have been any meaningfull modifications to the engine especially a performance cam, it would be a good time to have the distributor centrigugal advance checked and recurved...that and if the distributor has seen over 80,000 miles reconditioning and recurving should be worthwhile IMO
 
TR 6 1973 as is mine with PEX ing. yes retard vac. flyweights adv. If your diaphragms are bad will lean carb backfire posable. ( note they are keyed so only go in one way. ) I have lost several and hole can be small I carry extra ones and change both to keep carb balanced. I have a performance cam and did not change curve good idea! Madflyer
 
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