MoparBrit,

Any chance you can get an O2 sensor installed in your exhaust downpipe? If you are lucky a muffler shop can weld a bung in for you for just a few dollars, otherwise they can bend up a new down pipe with a bung welded in and cut out the old down pipe and install the new one for a few dollars more (hmmm, Clint Eastwood movie me thinks?).

Anyway, a narrow or wideband (better) O2 sensor will make all the difference in tuning your rig--both the jetting and, by association, the timing. You don't have to get a fancy air/fuel ratio meter if you don't want to, a voltmeter will do just fine. An A/F meter IS nice to have though, you can read it at a glance at speed, or better still is a logging instrument (not too much $$, but certainly not cheap). Plug reading is a rather arcane art that is approximate at best. Knowing the A/F ratio is what you really want. Think about it this way, if you could pay someone $100 to tell you exactly what to do for jetting your rig would you? That is (more or less) what it will cost you to get a narrow band O2 sensor installed--the narrow band will tell you if you are rich or lean or stoich...the wide band will give you great details than the narrow band.

I gave up plug reading as a waste of time, the O2 sensor tells me exactly what my air/fuel ratio is, which I then compare to performance (timed "sprints" between land marks, etc)--I tweak my jetting accordingly. This is, of course, what a good electronic fuel injection system does ALL the time, i.e. tweak the fuel/air mixture according to its engine map and engine loading. Carbs perform as well as fuel injection (generally speaking) but they don't have that adjust on the fly feature that an ECU brings to the table.

I think some more metering is what you need in order to fine tune your rig (A/F ratio, vacuum gauge, tachometer, etc). What's not to like about more instrumentation!

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Slanted D150

Less work and less money: a Gunson's Colortune. I'd bet a steak and kidney pie that MoparBrit knows what this is, and I'd lay even odds that he has one.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

mmmmmmm Steak n kidney............ don't forget the hp on it!

Yes, had a Colourtune and sold it. Bought a Gunsons analyser. Just need to get the bloody thing back from my mate with his perpetual collection of Triumphs.

Absolutely baking here today. Supposed to be much cooler tomorrow so I'll get a chance to muck with it again.

Here is a quick question before I go have my tea (see Dan, went and got me hungry now with the talk of S n K). Thermal switch in the air cleaner, the one the vac line is hooked to and then out to the air inlet door. Is that supposed to make a buzzing noise? My guess is no and that there is a bit of a vac leak there due to a semi faulty switch? Air door is closed when cold and I checked after a run and it does open so the switch does work. I just noticed it buzzing when I took the air box off and laid it to the side while it was still hooked up and the engine was running.

Now to call my mate and get my tester back!

Oh, and in the specs of the car, forgot to say stock exhaust. I'd like to upgrade to the 2.25 pipe and new muffler when I get some more funds.

Thanks everyone.

Cheers

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From Mopars to classic Minis and back to Mopars in 19 years flat!

Will work for roast chicken crisps!!

Those Gunson plugs work nice at idle, but who ya going to pay to eyeball that thing when you are wizzing down the road!?

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Slanted D150

What's that? Sorry, you were drowned out by the noise I'm making eating my chips with brown sauce. You'll forgive my mocking the curious spectacle that was English engineering (or you won't forgive it, but I'll probably carry on doing it either way ). All my bicycles are Notts-built Raleighs (and one Norman) with Sturmey-Archer gearhubs, but consider: The Germans have unlimited-speed motorways, so naturally they build cars that'll cruise effortlessly at triple the fastest US speed limit. The Swedes have brutally cold, dark winters, so naturally they build well-lit cars that'll start immediately at seventy below and remain sure-footed even on the slickest ice. Americans are notoriously neglectful of their cars, so the Americans build cars that may not be very good in terms of driving dynamics, but stand up to a level of abuse and neglect not compatible with other nations' cars. The Japanese culture values coordination and harmony, so naturally they build cars that go and go and go and go and then BAM, everything on the car falls apart all at the same time. The French...erm...never mind, bad example. My point is that it rains all the time in England, so naturally the English built cars that failed to start (and bikes that failed to stop) in the rain. Doy? :shrug:
No, it's gone leaky. Sometimes these can be made to behave by disconnecting both vacuum hoses and flushing through with spray carb cleaner. Otherwise replace it, see here.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Where's the pickled onions Dan?

I'm going to have to correct you on the English cars. Mini starts a treat in the rain. You have to clarify though. Starts a treat initially, then you get going and it sputters to a hault and won't start. Dizzy mounted right behind the grille on the front of the engine is wonderful to work on, but a bit of a bugger when it comes to water getting in on it. No problem though, just fit the old S boot or do like a mate of mine does and fit a rubber glove over the dizzy with the plug wires running out of the finger tips! Now that is a sight to behold!

Used to ride old Holdsworth and Falcon road bikes a long time ago. Nothing like Reynolds tubing.

Thought as much on the thermal switch. I'll give it a clean and see if that does anything, but otherwise I'll be trying to get a new one. I need to put in a small order with Rock Auto anyway as I see they have the NGK plugs and also carry the Dorman studs and nuts for manifolds. I used to have a discount code for them somewhere from when I rebuilt the front suspension and did the brakes. Been a while though so probably run out anyway.

Hope to get to work on the Dart today and see where I'm at.

tlrol
Love that "who you going to pay" bit. Reminds me of who you gonna call??? Plug busters!

Cheers

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From Mopars to classic Minis and back to Mopars in 19 years flat!

Will work for roast chicken crisps!!