SENC

Nice! And welcome!

You make a good point. It really isn't that hard to imagine the Lucas/Lotus gods causing a plague of generator issues with bravado like that!

2 rebuilt and running smooth (bench tested as a motor, to bed in the brushes), and plenty of bits left over for the parts bin - though it is hard to imagine enough miles to burn through 2 generators. Next job, while waiting on pistons for engine rebuild, is getting the coil springs back on the dampers.

A little puckered after that, I guess?!?

No, these constant depression carbs have only 1 circuit (unless you count the cold start device) with metering of fuel delivery accomplished by the needle in relation to the jet. They are ingenious in their simplicity, but as a result adjustability is limited, and all the parts need to work together as designed or they can be very frustrating.

The needles are having the impact you'd expect, given their profile. Move them relative to the jets (by either adjusting the needle height or by adjusting the jet height) and you'll get a change in initial richness. Once those are set, but profile does the rest as the piston rises and falls - and, in theory, the right profile allows more fuel at the same time the opening pistons allow more air, and you have relatively stable AFR across the range (assuming slow, smooth acceleration/cruise type conditions, not WOT). I think I have all that right! The challenge with these adjustable needles is that there is VERY limited adjustment range - just over 3 turns in total as I recall - so the most important bit is getting jet height right. Only then does the needle adjustment allow you to tweak within the right range. Also inspect the jet orifice - it should be round, but if the old jets were retained when the carbs rebuilt it could be that they are worn (a proper setup has the needle "leaning" to one side of the orifice, so over many thousands of rises and falls can wear a groove into the jet orifice). Not knowing the PO's shop, I'd double check to make sure piston springs were actually installed - and maybe inspect them to see if they look old and tired (they're light springs, so not sure anything other than missing, broken, or different one to the other would be visually notable). There are 3 different versions, it may be that you need a stronger spring. A footnote - converting fixed needle 175s to adjustable needle 175s means replacing the pistons. The Burlens/Zenith technical manuals will tell you these are matched components and should never be changed. Plenty of us have done so with positive results, but I guess there is always a chance of something being just out of tolerance enough to cause operating challenges. How is your timing set? You might note in the LSB attached earlier that Lotus suggest a static timing for Stromberg that (as I recall) is lower than standard along with change to adjustable needles.

Jet height changes should effect the entire range, I'd think, as relative relation of the needle and jet define initial mix - needle movement with the piston then adjusts with air flow. Lower jets should mean richer conditions throughout the range, higher jets would mean leaner. Though I certainly suspect the relative contribution of jet height is less up the range. The temp compensators and idle mix screws can contribute to lean-ness - I'd make sure the idle mix screws are seated fully, and I'd probably fully seat the temp compensators if I had any doubt about their working condition just to take that variable out of the equation. Do you know whether the fuel needle valves were replaced on rebuild? I can't remember if there was a size change when I rebuilt mine to non-emissions spec. Last, if you haven't seen the LSBs for this modification, I've attached pics - may be helpful.

Runs well and plugs look ok? If nothing else is telling the lean tale I'd be leaning towards to tailpipe cause. If plugs are confirming the lean state, you might check the jet height. I know they aren't technically "adjustable", but if not set at the right height you can never get them dialed in correctly. But I'd think you'd notice that is running state.

Engine, too. But you know that thing screams with 200hp!

Spent some time this weekend prepping my sump for painting... ... and beginning a refresh of the generator. The one on the far right came with the car, a replacement, an Australian made Lucas C40 from 1966 that I'll redo as a spare. I had 2 spares - one from 1964 that I'll likely use and one from 1960 for parts. Finally coaxed out the woodruff keys with a bit of Kroll, heat, and a mole wrench. The armature all look lightly used and in good shape, and the brushes on the 64 and Aussie generator barely worn. After cleanup, paint, and replacing the bearings and bushes should be good as new. The red 64 unit is so clean, it was either lightly used or rebuilt and set aside to gather dust.

I'm pretty confident I bought the right model for me, but since I've been taking it apart for inspection and renewal I haven't put but a few hundred miles on it in the year I've had it. But it was clearly the right car for the first 2 owners. Originally purchased in 1965, the first owner and his wife and first child used the Seven extensively, not just in the UK but across northern Europe. I have a couple pictures of them traveling and camping in the UK, and a great story from her about the 3 of them (child <2) traveling from Norway to Germany and then heading towards Greece in the snow before all catching cold and diverting back across France and to the UK. They then took the Seven with them when moving back to Australia, where she told me she would put the 2 boys in the passenger seat and the bassinet in the back for the baby. With 3, they sold the car in the late 60s - and the next owner loved and drove it until 2001. Combined, they put about 49k miles on the little Seven, and by the odometer it has had less than 1k since (seemingly confirmed by the engine and gearbox internals now that I'm in them).

It's been a while since an update, but slow-going right now as I search for and gather parts and make decisions about what to invest and do. I am having the cylinders bored (to 83, as we found them to have been previously bored and sleeved) and am working with Tony Ingram on having some pistons made. The engine still had the early 116E rods, and knowing their reputation I'm strongly leaning towards updating/upgrading them. On the head, I'll be replacing valves and springs. The gearbox externals are cleaned and painted and innards disassembled, cleaned, and reassembled - so all bagged up and ready to go back together when the engine is ready for it. I was fortunate to find a NOS 7.25" AP clutch housing/pressure plate and separately the correct 7.25" clutch plate for reasonable sums so will replace what I had even though there is good life remaining in them (will be good backups). The dampers and springs tested out remarkably close to original spec - a good thing as the dampers are the sealed Armstrong variety, which I've learned aren't rebuildable. I did get new eye bushes from the Armstrong successor (Harvey Bailey Engineering - very helpful folks), and otherwise am cleaning them up for reassembly and reinstall. I hate having everything apart as we've had some spectacular weather recently, but know this teardown was the right call and that I'll enjoy it when done.

Great stuff, Ross, thanks for sharing! Henry

Looking good, Ron!

Excellent!

Agree! Thanks for all of the updates!

It is kind of a big dill!

Camden is a lovely, historic town in the middle of horse country in SC - well worth a visit. My 7 won't be track eligible without rollbar or even belts, but I'd love to come join, meet, and contribute if the timing works out. Henry

The video link in this old post of mine still works, just is not embedded. https://www.usa7s.net/vb/showthread.php?12653-65-Lotus-Seven-S2&p=116016#post116016 Stay warm.

Same for me, John. And clicking on the links doesn't seem to work, either. Durn snow.

We appreciate your diligence in protecting us!

Well-edited, @JohnCH! How much did you have to cut to get to this concise, non-offensive post?

Adding a few more. This end also M10-1 thread (EDIT - correction that I believe this is actually 1/8" BSP, as noted above), and I got some close-ups and measurements of the fitting for you.

A few pictures for @escondidoron... Ron - I measured the engine end fitting - it is M10-1.0 (EDIT: thinking on this further, it does not make sense that this would be an m10 fitting, it is more likely a 1/8 BSP). I'm betting this end is the same, but I didn't want to force it.

Thanks for all of your efforts on our behalf - know this isn't easy, but also know it will be great on the other side!