’66 Volvo – Running on two cylinders

After stopping for a load of petrol the 122 started shaking like crazy, I stopped at the nearest business and popped the bonnet. The engine was barely running and shaking like crazy, it sounded like it was running on 3 cylinders. I removed the #4 sparkplug wire, nothing happened; that cylinder is dead. I removed the #3 sparkplug wire, nothing happened; that cylinder is dead. I removed the #2 sparkplug wire, the engine died. So 3 and 4 are dead, 1 and 2 are fed by the front carb and 3 and 4 are fed by the back carb. The plugs were getting fire and the air filter is not clogged so, we have a fuel problem on the back carburetor. I started to remove the fuel line that fed that carburetor and it was spraying like crazy. Just what I thought, the float jet (needle) is stuck closed. A good Samaritan from a local British car club stopped by to help, we took the fuel bowl apart and the ball bearing in the needle had popped out but stayed in place effectively making the needle longer and stuck on the closed position. We pushed the ball back into the needle and used some pliers to slightly bend the top of the needle over the ball to hold it in place, the needle was aluminum; easy to bend.

I reassembled the fuel bowl and reconnected the fuel lines. The engine cranked immediately, it was running beautifully, but as the guy said; the jets really need to be replaced. I was able to drive home with no issues. I turned to http://www.mossmotors.com/ for replacement parts, at great place for SU carb parts. I noticed a few months back my carb piston return springs were the wrong type and not the same springs. So I ordered new piston springs, new alcohol resistant floats and Grose jets. The Grose jets were hailed as “better than stock”. After purchasing the Grose jets I read on the internet about possible flooding issues with these jets; surely not. I reassembled the carbs with all the new parts, it was running beautifully. I let it warm up a bit, then revved the engine, fuel started pouring out of the back carb; yes flooding. Since the exhaust manifold is just below the carbs, this was a very bad situation. I spent an hour adjusting the float level and messing with this stupid jet. I just gave up, I needed some normal jets fast, we have a local British shop in Maumelle. http://www.mcleodsbritishcars.com/ wonderful little shop. These guys have a ton of knowledge about British cars, fortunately for me the Volvo shares the same carbs with several British models. They had the jets in stock and even gave my some great advice on installation and tuning. I installed the new jets in the fuel bowls and have not had a problem; she is running great. I also replaced the upper fuel filter and all the fuel line from the pump to the carbs. One thing this car is teaching me is that “new and improved” is really not what you need. If part A has been working fine for 50 years, replace it with another part A.

Products used: