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New Topic - does't run any better this year

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don't worry - not going after timing quite yet - just know it needs to be set as part of this.
I found a diagram though that says I have it backwards (timing that is) that BTDC is to the right looking down.

That being said I'm almost certain that the last time I reinstalled the carb without a gasket - oops I wasn't going to admit that - don't read the last line. So, job one - check the installation. Then we are going one by one through what you have described.

will keep you posted
 
DrEntropy said:
Just a WAG but, does the piston drop from being raised to full "up" with a no resistance "clunk"?
Click to expand...

had it apart last night and it drops with a audible "tap" more than a no resistance clunk.

There seems to be a little side to side play in the needle - is this right?

Also, the cap has a "tube" in the casting (along side the plunger) it is closed and doesn't seem to have a purpose is there an alignment direction for the cap?
 
Needle should kinda "float" around, yup. "Springy" side to side. THAT sounds like normal. As does the piston drop.

No "alignment" on the screw-in cap. The "tube" is an equalization device to allow vacuum/pressure to be the same on inside of the plunger tube as in the dashpot. Keeps it from sticking in the "UP ' position... obviously not your issue. :frown:
 
thanks

well, I'm stumped. found and put a gasket on it

took the diaphragm apart - checked it - as near as I can tell, it's perfect

made sure the tabs fit as it went together

made sure gas was flowing

reassembled

got it to fire twice on starter fluid

plugs are wet

put in dry plugs

smells like gas

still nothing

spent a minute cleaning up and found my grose jet - I've never installed it cause I know lots don't like it - but should I try?

now what?
 
Forget th' 'grouse' jet thingies.

If ya smell gas and it doesn't light, it could well BE iggy issues. Have you a timing light (induction type) you can rig up to check the plugs are getting whacked?
 
...sorry it took so long to answer. I'll be here now. If it lit with starter fluid (not a thing to repeat a lot, BTW) then the fuel delivery is still the "prime suspect" here.
 
JP, sorry bud. I just can't talk about your carb.
 
Update, Dave from Tillsonburg (14dna)came by this morning to help - thanks Dave.

Anyway, we are pretty sure the floats seem to be the issue as we replaced the valve twice and it is still flooding every time you start it. Other than that, it really did want to start. Hope to get one this PM so we'll keep you posted.

My current theory is that either there is a small leak or they are porous and that they therefore worked well at the initial start (after 15 years to dry out) but as they have sat in gas for the last 2 months have filled up somehow.

I'll let you know
 
JP, do you have an electric fuel pump? If so, it is not uncommon for the output of some electric fuel pumps to overpower the float.

Here is a test you may consider trying:

1) Turn the car over a few times to fill up the carb bowl.
2) Disconnect your fuel pump. If you have an electric fuel pump, disconnect the fuse. If you have the mechanical fuel pump, disconnect the hose to the carb and stick it in a gas can.
3) Try to start your car. If it fires up and idles, then your problem is definitely the float.

It may be hard to start at first if things got a little flooded in step one. But if you can get it going, there should be enough fuel in the bowl to keep it running for a minute or two.
 
Pull the floats and shake 'em. If they "answer back" with anything sloshin' in 'em you found the problem.

Dave knows what to do. :thumbsup:
 
Another alternative theory for ya, JP...
The engine ran well <span style="font-style: italic">before </span>the alternator swap. Nothing was done to the carb in the meantime. <span style="font-style: italic">After</span>; bad runnings, plugs wet, smells like gas. To pull the alternator you have to fiddle around where the dizzy is, and things can get knocked around. Call me nuts, but I think part of your problem is a weak spark. A spark that's not fat enough will make a carb <span style="font-style: italic">seem </span>to run rich.
The rest of the issue could be the Zenith's old gremlin of running rich by not sucking the piston up hard enough, which goes back to the vacuum problems. Neither of these problems on their own would ground ya, but both together might!

Just food fer thought.

(p.s. When looking at the engine from the front, BTDC <span style="font-style: italic">is </span>counterclockwise. Usually on a car, 'right' and 'left' is from the driver's seat, which is counterintuitive when referring to engines!)
 
At risk of sounding like a know it all, today when I saw this car, it would run for about 10 seconds.
Then the fuel would pour out of the carb.
The fuel pressure is good, and the spark is excellent.
It has way too much fuel.
Because we tried three different needles, my summation is float sinking.
We will know better in a day or two and will keep everyone up to speed.
Thanks for all the help and suggestions.

Dave :savewave:
 
Thanks again Dave - though 10 seconds is way optimistic. It will run until fuel gets into it and then it floods.

got another float today - swapped it out and nothing changes. The fuel still pours out. I left the grose jet in so tomorrow will go back to the original. however, I am not at all optimistic.

so, to recap.

1. It did run in October.
2. The timing seems close enough to start.
3. I have spark

4.it is the original (not electric) fuel pump and there is lots of gas coming out.
5. I have tried three different jets - no difference
6. I have tried two sets of floats - no difference
7. I have tried two different diaphragms - no difference
8. the diaphragm tabs are correctly located
9. the piston moves smoothly
10. the needle is new

and gas keeps pouring out of the carb.

one the other hand, I can remove, change out the floats, adjust the floats and reinstall the carb in 18 minutes.

any thoughts about what next?
 
JP;
This is a mechanical pump?
Fuel pressure should be around 4Lbs.
Maybe it is over pressured?

Dave P.S. just a thought
 
not sure how I could check that - however, when I let it flow into a small tub, it seemed "right"
 
JP,
Have you tried temporarily disconnecting the hose that runs from the ZS carb to the carbon cannister? Maybe the cannister is pulling a vacuum on the carb, resulting in fuel overflow.
(Just a thought - cannot think of anything else at the moment)
 
no canister at all - there are only 3 hoses attached to the carb

1. gas in
2. vacuum
3. hose to the valve cover

As near as I can figure, it can only be two places.

either
fuel line to reservoir/ floats
or
reservoir/ floats to chamber of carb.

nothing else makes sense.

tonight's job I think is to pull the carb again and bench test the snot out of it

suggestions gratefully received
 
just pulled the carb again. checked and rechecked the floats and the jet. everything opens and closes as it should. reinstalled - she wants to start soooo bad, fired and actually ran for an instant - then gas pouring out again and nada.

so, anyone with ZS carb experience, here are my next two possibilites

1. that somehow the pump is pushing hard enough to overcome the floats. this seems unlikely as it is the original mechanical pump.

2. the needle. I replaced the needle - though I can't remember how. I took the grub screw out but the needle stayed in. the brass bushing around the needle is not flush with the bottom of the piston.

other than those two, I'm coming up empty.
 
Try the test I detailed previously in this post. It will tell you for sure whether the problem is with your floats.
 
I have no experience with a ZS carb, but is it possible that you have the inlet line hooked to the vent line and the vent line hooked to the inlet?
 
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