Poor running

[Alex]

Morning,

I'm trying to get a +2 engine running properly. This was mostly re-built by an 'expert' a good few years back but not run until recently when I took the project on.

My problem is that the engine runs ok at tick over and will rev quite freely to about 4-5000 rpm. On the road it feels slightly lumpy and again struggles past 4-5000 rpm.

I know the cam timing is ok, plugs ok, ignition timing ok, new points and rotor arm and the carbs are set approximately right. The only thing I am suspicious of is the plug leads. They are about 10 years old, so would a failing lead/s give this problem? Any advice would be much appreciated.

Regards,

Alex

[neilsjuke]

Yes do change the leads and the Dist cap (always fit a new rotor arm with a new cap) and check that the dist advance wegihts are free and check advance with a strobe.
Neil

[ill_will]

what do the plugs look like?

[ill_will]

and when you say the carb jetting is right, what have you got in them?

[Alex]

The dizzy cap is new, forgot to mention that one.

The plugs are a bit on the rich side apart from one which looks to have some moisture on the bottom of the ground electrode but is generally black. This makes me think its not burning all of its fuel and I susspect the plug leads.

Alex

[bill308]

The ignition system, including a smooth advance, and cam timing must be correct and confirmed, before carb tuning will be fruitful.

A compression check and leak down test would also be desireable.

Bill

[jeff jackson]

Hi Alex,
Agree with the bob weights in the dist. Check that they move freely, and the correct springs have been fitted. These can be purchased, so don't panic if they are incorrect or broken. Also change condenser, points and gap the points correctly. Change the plugs and leads.
Next balance the carbs, using a carbtune, and then mixture using colourtune, colourtune is not the best, but gets you near enough.

Regards
Jeff 72+2