Timing 68 Stromberg

[h20hamelan]

I have been playing around with my +2, before I put the Patton Fi on. Trying to get rid of the off idle stumble. Played with needle years ago and had it pretty good, but still a stumble at 12-1500 in any gear torque load etc.
Dwell has always been about 55-60.
Advance about 10 at idle 850
Tonight, I hope it didn’t skip a tooth or something. It seems fine, but timing is way out. I get it to 40’ at 900rpm but thats as low as it will go. So either thats been the problem all along (i have 3 timing lights which I like to use my old Niehoff and Craftsmas vs newer digital Autel). I rotate them and surely have tried them all over time.
Before I pull valve cover tomorrow morning. Anything I have missed or any opinions appreciated please.

I can put a different distributor in, last time I looked about 3 years and 1000 miles ago, weighs and springs fine. But I dont think this is why it would advance so far. Also, the timing light still indicates advance with higher rpm’s.

[oldelanman]

It may be that the distributor cam plate is partially siezed on the shaft, that could explain both issues ... not advancing freely as the revs increase causing your stumble and now stuck in the fully advanced position. With the distributor cap removed you should be able to turn the rotor anticlockwise against the advance springs and it should return freely when released. It's supposed to be lubricated periodically with a few drops of oil down the centre of the shaft but this tends to get overlooked. There's no reminder on the Lotus or aftermarket rotor arms like there was on the O/E Lucas item.

Edit: Just reread your post and I see you say it still advances with increasing revs so not likely to be a sticking cam plate.
Maybe the distributor clamp is loose and it's rotated a bit in the block.

[h20hamelan]

Does return, Though only moves about 1/16, and me not knowing what normal is
I think it is a twofold problem, front carb seems to be overflowing at idle now (didn’t notice in the dark last night). Still way too advanced, so after some penetrating oil last night and this morning it seems to drop below the 30 mark but only marginally so I’ll keep boiling it and obviously I have a clog or something in my front carburetter
Type 43 distributor

plate tight.
Anyone know how much movement there should be in the rotor arm, 1/16 seems about correct as anything more would be past 40'

[oldelanman]

Yes 1/16" movement is about right. Just checked a spare distributor on the bench and get about the same ... it won't rotate to the full mechanical advance as the weights tend to jam. So long as you can feel the springs pull it back it's not seized.
If you doubt your timing light(s) I would check that your front pulley timing mark corresponds with engine TDC and then check the timing statically.

[h20hamelan]

Crap, well I would have done that not too long ago.
As it was near fine, outside of the stumble. Something I have never really gotten rid of. Had tried rebuilding Ac glass bowl, then electric pump, new distributor, carbs rebuilt, new electrical cap condenser coil etc and every time set to TDC and verified with long wooden dowel in #1

Thing is, the 10’ advance and it has been running very well until now. So unless the timing tensioner has slacked in not many miles, and jumped I am stumped.

Kind Regards

[sprintsoft]

Hello,

did you say you can see 40 deg advance at 900 rpm? I think if that were the case the starter probably wouldn't turn it over, it would kick back.

I made a mistake with a timing light that has an adjustable dial on it - if the dial slips wirthout you noticing it will give you some wild readings!

Nowadays I have a large piece of duct tape over the dial to keep it at zero... maybe that's your issue?

Regards
Iain

[h20hamelan]

Ah, no. I use the tried tested. I think my 68 has 4 slots in the pulley. So maybe 30’+ as maybe the first slot is 0.
Though I am not looking at it right now.
Correct, much or any adjustment it will kick back. And any further it will not start.
So into the attic I go for a distributor.

Kind Regards