two dead cylinders 308

Did you put new plugs in those 2 cylinder? I've never had luck getting a gas fouled plug to fire again.

A plug wire and can definately ohm good and be bad. The ohm meter checks the conductor at 0 current, when current is flowing you can easily get a different result. Also, the meter doesn't test the insulation....shutting down after it got wet sounds like insulation to me.

 

You need to check if the plugs on the affected cylinders are firing...my guess is they're not. A Timing Light is the best way to do this, but you can check without by removing one of the affected plugs, hold it (using something insulated!) with the tip touching the engine, and see if it fires when the engine is running. You may well need assistance to do this.

Assuming they're not firing, but the other cylinders are, then it's most likely to be the leads, the plugs or the extenders. Try removing them and replacing them with parts from known good working cylinders.

Hopefully it's just water in the system somewhere?

 

Do I assume that you checked the plug well (hole) to make sure that there is no water in there from the rain that you had. And I agree just take a timing light and check the plug wire to see if it is firing. If that all checks out replace those 2 plugs. As you know you have feul so you need to see if you have spark.

 

The 2 cylinders that are gas fouled are both on the same carb? This sounds like a float problem?

 

Good thought Billy. So maybe there is dirt in the neddle valve or a float sinking issue.

 

I had a sticking check valve on the accelerator pumps on my '78 308 and it would foul plugs in about 2 miles. I discovered the problem by looking down the carbs while running and slowly increaseing rpm and I would see the accelerator jets dribble fuel.
Hope this helps
Merry Christmas
Larry

 

I had a dead cylinder and it was due to the air bypass screw being too far open on the throat that supplied the dead cylinder. In the process of balancing the air flow in all carbs I had the air bypass open to the point that the Air/fuel mixture screw was ineffective. When the air bypass was closed a small amount and the A/F mixture readjusted the cylinder stated firing again. Also the carb you indicated has the vacuum hose to the brake assist. You should check for leaks. Happy Holidays.

 

Two things to check. Once a plug is fouled, no amount of cleaning can make it work correctly. I discovered this helping a buddy work on his Triumph TR-3. And plugs are so cheap. Second, coil may have enough to fire a plug that is resting up against the cylinder head but not enough energy to fire with the pressure of compression. YMMV.

Jeff Pintler
89 348tb, 86TR