Engine idle issue?

[Frankd1]

I bought my first spider last weekend, a 78 twin carb..

I have a question about an engine issue I may be having..

When I test drove the car it seemed to idle and run smooth..It didn't seem as though it had the same get up and go as other spiders I have driven..but that could of all been in my mind...

I trailered the car home and once I unloaded it I started it up.

It settled into what seemed like a really low diesel sounding idle..loafy and clackety..

The exhaust had a "whump whump" sound to it...kind of a muffled Harley sound...

Not sure what it could be but it doesn't sound right.

If I tap the gas after I start it, it'll stall. I have to let it run for a bit first..

Noticed a lot of condensation coming from the exhaust and some unburnt fuel on the garage floor..

Could it be:

Carbs out of adjustment?
Bad timing?
Issue with the ignition system?
Cylinder not firing?

I have two short videos, how do I post those?

Thanks

[bradartigue]

Sounds like the distributor is loose, timing is out of whack. Check the ignition timing.

[Frankd1]

Thanks, I'll look into the timing...

How do you post short videos taken on an iPhone?

[bradartigue]

I don't think you can.

[Frankd1]

Here are 2 links to youtube for the engine idle..

https://m.youtube.com/watch?v=37US1iZGLd4

https://m.youtube.com/watch?v=9kAJWMIOl1Q

[Frankd1]

Any thoughts?

[Frankd1]

Now that I was able to get my ignition switch to unlock I was able to start some troubleshooting for this idle.

I started up this morning and the engine idled with that Harley Davidson "whump whump whump" sound to it. Lots of condensation from the exhaust and a gassy smell...

With the engine running I pulled the plug wire from the 1st sparkplug and the engine quit.

Plugged back in and started up again, this time I pulled the wire from the 2nd plug and the engine kept running with not much change. I held the wire close to the plug and while I didn't see any arching it sound like the rpms wanted to increase a bit. I plugged the wire back onto sparkplug 2 and no change in idle.

I pulled number 3 and the engine quit.

Plugged back in, started up again and I pulled the plug wire from the 4th spark plug and the engine kept running with not much change.

Some other symptoms: while the engine is idling, if I give it some gas it feels sluggish as the rpm comes up...I also have to apply pressure slowly as it seems as though it will stall out. I can get the rpm up and hold it at lets say 1500 or 2000 after slowly increase it..

When the engine cools down I will pull the spark plugs and have a look..

Does it sound like I'm only firing on two cylinders? number 1 and 3? There is a fair bit of engine vibration and its noticeable in the exhaust pipe under the car as well..

Should I replace the plugs and wires as a starting point? What type of plugs and wires do you guys recommend?

Thanks

[bradartigue]

It sounds like you are running on at least two - probably two and sometimes three (it really struggles to run on 2!). I would inspect the cap, rotor, wires, plugs, points, coil, all of it.

[azruss]

You definitely have one if not to cylinders not contributing to the cause. what kind of carbs are you running. if you have DCNF then each one is adjustable and you may need to balance your carbs. First get your spark figured out. if you want to test 2 and 4, get a good plug and connect the plug wire to the plug and ground the threads on the motor and see if you are getting a spark. (use gloves) pull your plugs and see what they look like.

[Frankd1]

Thanks guys I'll get into this more tomorrow and post back.

I will check on the carbs - I want to say twin 32 ADFA.

I've only had the car for a week and while its in pretty good condition overall, it has a couple of issues I'm working through.

I'm going over and through the car front to back and checking everything over.

I should probably just get new plugs and wires to start fresh in this area...

What do you guys recommend for plugs and wires and where to buy?

As far as engine oil, I bought some shell rotella 15w40 and will be picking up wix or purolator filters.

I have an address in the USA (Michigan) that I frequent so ordering from the U.S. is no probkem

[131]

I want to say twin 32 ADFA.

IDFs. Nice when they're right, but can be a pain to get them there.

[Frankd1]

I figure I should probably do a compression test while the plugs are out..

What's the proper method for a carbureted car?

[Frankd1]

I think I made some progress...Here's what I did so far:

-checked battery voltage at battery terminals = 11.9v

-checked voltage at coil terminals = 11.0v

-checked voltage at coil terminals with main wire from distributor to centre of coil disconnected at coil - 11.0v

-pulled the plugs out. I noticed 1 and 3 were dark and 2 and 4 were dark and wet. they smelled of gas. cleaned the plugs up and checked gaps:
-plug #1 .028, plug #2 .028, plug #3 .027, plug #4 .030

-connected each plug to its respective wire one at a time, a friend turned over the engine while I held the plug threads against the exhaust manifold as a ground. Each plug had a little blue spark between the centre electrode and the side electrode.

-spark plugs are NGK BPR6ES

-I tried to do a compression test but I think my tester is faulty or leaking air. I screwed it into the spark plug hole and turned the engine over 10 times. The needle on the gauge bounced around but would not settle. Once I stopped cranking the gauge needle went to zero.

-put everything back together and started up. It settled into a much better idle albeit it seemed a little low....I was able to drive the car.

What is the proper way to check the distributor. points. rotor, coil, condenser etc?

Are these NGK's ok for this engine?

Proper method for a compression test on a carb car?

Some photos:
plug 1:


plug 2:


plug 3:


plug 4:

[bradartigue]

Running too rich. Black plugs = too rich. Those might not even fire (clean them up before using again)

[Frankd1]

Thanks Brad, I figured that was contributing. Once I cleaned the plugs up and checked that there was spark to each plug the engine ran much better but is still on the rich side. Once warmed up the idle settled at just under 1000....maybe around 900.

some questions:

1. Are these plugs ok to use: NGK BRP6ES. gaps were: .028, .028, .027, .030

2. I checked the voltage at the coil terminals but as far as the distributor cap, rotor, points and condenser, what should one be checking for specifically at this area?

This is my first carbureted car with distributor and points so its still a learning process.
I am considering a switch to electronic ignition down the road.

I tried checking for any stampings on my carbs that would tell me the model but I wasn't able to find any. They are definitely Weber, here are some pics:











Do you know which version these carbs are?