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MG MGB Technical - Adjusting points -- methods?

Who here has the easiest method for adjusting points accurately? I always find it a pain in the rear to get the distributor in the right position to fully open the points.
Steve Simmons

Steve - The absolutely easiest way to eliminate this problem is to install a pertronix ignition - you then only have to adjust timing one time and then leave is alone. If you stay with a points ignition, then what I used to do was to remove the distributor whenever I replaced the points and made the initial setting. The other method is to use a dwell meter to set the points, but you have to get them set so that they will open enough to get the car running so you can take a dwell reading for a starting point. Good luck - Dave
David DuBois

The easiest way to do it is to take the dizzy off the engine - just slacken off the pinch bolt and pull the dizzy straight out.

After setting the points you should reset the timing anyway - so it saves a lot of time in an inaccessable corner of the engine bay!
Chris Betson

Steve

Do you have a dwell meter or are you using gap gauges? Dwell is easier for me to set and I know its right on. At least that's what i did before I switched to electronic ignition.


Mike
Mike Phillips

Like Chris, I always remove the distributor from the car to both clean and lube it when installing new points. Dwell meters are a wonderful check after the dizzy is back in and the engine timed. A pain in the neck to use when setting up though. The Chevy V-8 engines used to use a distributor with a covered port which allowed you to set the final dwell by inserting an allen wrench into the dizzy and adjusting the points gap as the engine was running. Trying to adjust the points gap on an LBC is considerably more difficult, thus most of us use the feeler's gauge to set the point and later verify the dwell is within specs. Les
Les Bengtson

Why not just put the car in 1st or 2nd gear and rock the car forward or back until the points are open widest. Easy as pie. Absolute precision isn't really essential.

Roger
'69 Roadster - with points
Roger Hotelling

I usually try to rock the car as well but I've found it to be a real pain getting it in just the right spot.

I do have a dwell meter but rarely use it. I guess I should learn to use it more often.
Steve Simmons

Like Les, I usually pull the distributor to set and then do a final check back in the car with the dwell meter. I find I can inspect the distributor much more closely on the bench than leaning over the wing....
Rob Edwards

Hi all..

Turning the engine over to set the gap is MUCH easier if you remove the spark plugs, but it is even easier to do it with the distributor on the bench.

Don
Don

...and when you lose the little screws that hold the points in, it's a lot easier to find it on the workbench than the engine compartment.

Regarding loosening the pinch bolt to get the distributor out: I like Paul Hunt's suggestion to remove the two bolts which hold the entire clamp to the engine block. Then when you stick it back in, you're still pretty close to the correct timing.


Matt Kulka

Matt, you only have to note where the vac advance pipe is pointing to get the dizzy back in roughly the same place - or you can scribe a line on the dizzy body and clamp to be 100% accurate.

The two bolts are easy to drop and need to be undone completely - whereas the pinch bolt just needs to be slackened a few turns.

No contest, IMHO.
Chris Betson

I also prefer to slacken the pinch bolt. I find it easier to get to. As Chris noted on another thread, the point's arm that rubs against the points cam can wear more in the first few hundred miles. Some of the arms do not, quite visibley, make full contact with the points cam and will wear until they do. This causes the gap to close up and the dwell to increase. Thus, checking the dwell periodically is a very quick and easy method of determining arm wear and whether you need to re-gap the points. I find gapping the points, with the dizzy still on the car, fairly easy. It is only trying to remove small screws, put the points set together and reinstalling the small screws that really begs to be a bench project. Les
Les Bengtson

Steve- Honestly I'm positive the best method is to buy a good quality new set with capacitor, wrap it in a tight cellophane, and install a Pertronix. Keep the cello-wrap in the glove box just in case. Cheers, Vic
vem myers

I take the distributor out to adjust the points by gap - much easier particularly on a RHD car. I remove the two clamp bolts rather than slacken the clamp bolt, although this might not be possible on a 25D, to avoid damaging the shoulder on the distributor body and keeping the timing - which should always be checked after adjusting the points anyway. Once adjusted it goes back in then I read the dwell for confirmation. Thereafter it is a simple matter to check the dwell at each service, I find both my roadster and V8 very consistent so rarely need readjusting.
Paul Hunt

On the cellophane-wrap comment. Substitute for a new set of points with a known good, used capacitor. Those little SOBs have been known (four so far in my life) to come out of the box duff and the last moment you need to find this is by flashlight in the middle of nowhere when the electronics pack up.
To add insult to injury, the thing'll probably be out of warranty by then as well.
T J C Cuthill

This thread was discussed between 06/04/2003 and 09/04/2003

MG MGB Technical index

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