SA-200 -- Compression, spark plugs, carb rebuild questions

On Fri, 08 Apr 2011 11:58:46 -0500, Karl Townsend


I would not condemn the ignition too quickly - as running rich can foul the plugs - which AFFECTS the ignition.

Of course it is the ignition that cauas the miss - but very often, in my experience, there are other factors that affect the ignition - other than bad ignition parts.

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wrote:

It's all a symphony. Distributor and all its little component parts, centrifugal or vacuum ignition plate advance, plugs, carb, float level, jet settings, flow of air through the air cleaner or lack thereof, plug wires, strength of coil output, condition and connections of all wires, condition and age of gasoline, gas tank venting, backpressure of muffler if obstructed, timing setting, point gap, spark plug gap ............. probably a couple of things I missed.
If any ONE of those things is out of whack, your symphony doesn't sound so good.
This is ABCs. I don't understand why it is all so complicated. But then, at 16 years old, I could have the heads off a 283 V8 Chebbie in an hour, too.
I guess it's like anything else. You got it, or you don't.
Steve
Heart surgery pending? www.cabgbypasssurgery.com
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True and not.
Was very true but now we have electronic ignition and electronic fuel injection. Different picture.
BUT it's easy to tell. Use a squirt of starting fluid. If it fires up & dies, it's fuel....
--
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David Lesher wrote in rec.crafts.metalworking on Sun, 10 Apr 2011 18:11:26 +0000 (UTC):

Don't be too sure. I once had occasion to drive out to Arizona. Before the trip, I did the usual tune up things to my Jeep. New plugs, plug wires, cap and rotor, new air filter, oil change. In west Texas, I started to get misfires/loss of power at wide open throttle(WOT) and high speed(highway driving). Ran fine otherwise. No fault codes from the computer, engine temp. OK etc.
All the while I'm in AZ, I'm thinking about what might be wrong. But it won't do it anymore.
I finish up the job and am heading back home, and it starts doing it again. I get off the road early and start to find out what's going on. I check for loose plugs, ignition wires. I pull the cap to check the rotor and look for carbon traces. Everything looks fine. But as I'm putting the plug wires back on the cap, I find that the center contact is not bonded to the plastic. I had dismissed an ignition problem because I had replaced all the parts. I had ASSumed that they would all be good.
If I had not done the tune up, I probably wouldn't have had any problems.
--

Dan H.
northshore MA.
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dan wrote:

That happens quite often. I got to the point that I never changed the condenser if the points were not burned since that indicated the cap was doing its job. I did keep a new one in the glove compartment. I have had more than one new spark plug bad. One time the whole porcelain blew out and the wire was swinging free right after it was installed. I thought I had major engine damage until I saw the wire loose.
John
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On Mon, 11 Apr 2011 01:20:01 GMT, snipped-for-privacy@privacy.net (dan) wrote:

Been there, done that, wore out the "T" shirt. You can often trust "experienced" parts more than "virgins"
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Steve B wrote:

I must still have it ... youngest son and I spent about 8 hours this weekend putting a head gasket in his 2k S10 motor . 2.2l OHV 4 , he had a radiator failure thursday night , which overheated it .
--
Snag
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Once you get the basics, it's all just paying attention to the fine points, labeling wires and "stuff", and remembering odd things. Other than that, a head bolt is a head bolt, a manifold stud is a manifold stud, etc. Coffee cans are/were great to keep bolts and nuts and "stuff" that goes together in one spot.
Another thing is keeping everything clean. I hated doing work in a driveway, or any other place where the work could not be isolated from sand, etc. It's nice when you can pull off a whole carburetor/manifold assembly, and sit it on a nice bench, and retrieve it at the right moment, all just like you took it off the engine.
It goes from there.........................
Steve
Heart surgery pending? www.cabgbypasssurgery.com
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On Fri, 08 Apr 2011 08:17:05 -0500, Ignoramus30421

Definitely replaceable, and very common part - but not as easily available as they used to be. Depending which set was actually used, they can be either very simple or quite tricky to replace. The one peice ones are simple - but there were quite a few "chinese puzzle" types as well -
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Winston wrote:

That is why I suggested a clean hose. Clear surgical tubing works quite well for this sort of testing. The carb looks like it has been washed and dried so no gasoline should be involved.
-jim

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wrote:

Almost a useless test as the needle may hold vacuum and still not hold pressure. (more common with the soft tipped needle than the steel one, but still possible)

The carb kit will also, in all likelihood, incluse a float level guage. Follow the instructions.

DEFINITELY put new lines and a filter on.

Could be, but gas leaking out of the carb is not caused by late timing or bad points - so we KNOW he had a carb problem. No guesswork involved on that count. Now that he has that fixed, he can check out the rest.
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I just had a realization about that fuel leak that I had.
In line between the fuel tank and a fuel filter, before the carb, is a 12 volt fuel solenoid valve.
It is normally closed. It opens only if the IGNITION switch is on. The point of it, actually, is to prevent fuel leaks just like the one I had.
The fuel leaked and I had ignition switch turned off.
So, obviously, the solenoid valve did NOT work and it did not do its job.
I guess, crap got into it and prevented it from closing properly.
Can those little things be taken apart? Or should I get a replacement one, they are $25 and I can get it today from McMaster-Carr. Maybe the new ones are better?
i
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Ignoramus30421 wrote:

The shut off valve probably can be cleaned. It was probably leaking for the same reason as the carb - dirt. If it can't be fixed it could be replaced with a manual valve.
To answer your other question - the points are replaceable. They can also be cleaned and filed if replacement parts are hard to find, but points and condenser should be easier to find than a carb repair kit.
There is good info on points in your repair manual. It also shows how to check the timing.
-jim

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Put the fuel filter upstream, assuming there's a manual cutoff on the tank itself.

Beware! Points have spacing you must set but using a feeler gauge that has oil on it will bit you on the YKW; the oil will carbonize.
--
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& no one will talk to a host that's close........[v].(301) 56-LINUX
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On Fri, 08 Apr 2011 08:29:58 -0500, Ignoramus30421

These are called a Murphy valve and normally cost under $10 on eBay. At least, that's my source for them.

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On Fri, 08 Apr 2011 08:29:58 -0500, Ignoramus30421

Ayup, or it rusted out.

Dunno.
-- From the Book of Aussie Bush Etiquette:
Never tow another car using pantyhose and duct tape.
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On Fri, 08 Apr 2011 08:29:58 -0500, Ignoramus30421

The fuel shutoff solenoid is a safety iitem - the engine will run fine without it. I'd get it running without the valve first - and if everything else checks out try flushing the old one. If you cannot flush it clean so it does not leak, THEN order a new one.
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I got it. Thanks.
I put the carb together and back on the engine. It seems to start fine. I did not keep it running for long because it is late and I do not want to annoy my neighbors.
But I want to say BIG THANK YOU to you and everyone.
i
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On Thu, 07 Apr 2011 23:25:37 -0500, Ignoramus23779

Y'think? <g>

I hope you rinsed with water first, then aerosolled it. Water can be a neutralizer for the base of the cleaner.

You gonna shoot video of it?
-- From the Book of Aussie Bush Etiquette:
Never tow another car using pantyhose and duct tape.
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