EN500 works only on one cylinder

[pacomutt]

Originally Posted by wally_m82a1

Sparks are fine. Further if I change plug for the previous one, engine starts fine.

I'm confused. If the engine starts and runs fine with a different plug, why are you looking at your carbs?

[sfair]

I always like to test the ignition system in a case like this first. It is EASY and CHEAP to do and rules in/out half of the equation in short order.

Using the recommended tester is the only way to put the system under load and check for poor spark. Using the old screwdriver or laying the sparkplug against the cylinder test is a good go/no go test (and risk ignitor punch through), but to check spark health, tester is what is required. It will point out low primary voltages, weak coils, wires, caps or ignitor. If the ignition system passes muster, then one can move on to the more expensive and time consuming remedies.

What more could you ask for $10 and 5 minutes of time?

[wally_m82a1]

pacomutt because I had plugs "A" then i swapped them for new plugs "B" when engine started work on one cylinder. About a month later i have the same issue and still have plugs "A" in garage so a decide to check them out and... both cylinders works.

[SWVA_08V2k]

The old plugs probably worked because they had time to dry off. And they probably got wiped off and cleaned up too. I would follow sfair's advice I would rather test the ignition system before I tore in to the carbs and found out that they were not the problem in the first place.

[wally_m82a1]

10$ sounds good but here its cost equal of about 30$. But if You both say it's important I'll look closer to this tester

-EDIT-
I just checked Ebay and i found this: Link
What do You think about it?

[SWVA_08V2k]

I do not know anything about your mechanical background. I am just a back yard shade tree kind of guy no "formal" training just a lot of trial and error and reading books to learn stuff. But if you plug is not firing then you probably are not smoking any and getting a strong raw gas small. But if the plug is hitting and you get getting black smoke out of the exhaust then you probably have carb problem. Can you tell us that.

[wally_m82a1]

SWVA_08V2k Do You mean strong raw gas smell? Yes i smell it but I tought it's because of that i start the engine in garage. Smoke is white.

[SWVA_08V2k]

oops! yes I meant "smell" not "small". Caught me on a typo. I am still leaning toward testing the ignition first just to rule it out.

I am not familiar with the 500 engines, but if you can swap plug wires or if the coils are interchangeable and swap them around and the other cylinder acts up then you know you have a problem within the ignition system. Just a thought.

*EDIT* It won't completely rule out the Ignition system but it will back to the coils

I am just fishing for details that might help possibly lead us to a more direct answer.

[pacomutt]

I know this won't be sfair approved, but I used to have an old Suzuki 550 inline four banger. When started, it frequently wouldn't fire on one or two of its cylinders. To get a spark "hot" enough to fire the plugs, I would partially pull the plug wire up on the plug's insulator about a half-inch or so, so that the spark had to make the jump from the wire terminal to the spark plug's terminal. With the engine running, I could pull up on the wire until I could hear the spark snapping inside the boot. The cylinder would immediately "catch" using this method. The spark at the plug's business end was then hot enough to fire the cylinder. I'd then reseat the wire and be on my way. I think maybe a larger gap on the plugs would accomplish the same thing.
I never knew if the added gap caused the spark to actually be "hotter", as in more voltage produced, but this method certainly worked!

[SWVA_08V2k]

Pacomutt, you know no even ask the guy if he checked the gap on his plugs. I mean that would be simple to check. I always check mine when I install them.