Hi,
On my standard 1275 motor, 1&2 cylinder spark plugs are black yet 3&4 cylinder spark plugs appear not as bad. The motor had been professionally reco a few years ago but the car is not registered so it sits in the shed and started up once a week. The engine has twin 1/1/4 carbies and a leaky between the joint LCB manifold 1 7/8inch exhaust. The charge light on the generator is on so on testing there is no generator charge. The vehicle has a PCV into the carbie manifold as well as Lockheed Brake booster. On idle when lifting the piston spring lift on the side of the carbie the car stalls, both sides. The choke is not connected, I engage the choke linkage by hand to start. The carbies have Ramflo filters with new elements. The car has new plugs ,points, leads,coil. The fuel bowl chamber is not leaking on the 1&2 cylinder carbie but is moist around the gasket. The vehicle runs on BP Premium Unleaded 98. If I put new or cleaned plugs in the vehicle they foul up within minutes. After 2 or 3 starts I have to clean or replace the plugs, as the vehicle runs like a sack. I have tried NGK BP5ES and BP6ES spark plugs the 5's being cleaner a bit longer. Also tried Bosch W6DC plugs same as NGK. I have NO4 needles in the carbies at the moment don't know if that is number 4 or NO4 just reading receipt. The timing is at 3 degrees. When I run the risk around the bloke the car run allright but seems to hesitate a bit, doesn't seem to rev as quick.
Please would appreciate any help or advice from anybody having had the same or similar problem.
Thanks

Just sounds like your carbys are not tuned.. You need to adjust the mixture setting on each carby. The right one sounds too rich and the left one sounds llike it could be correct. I'm not sure of those needles.. were your carbys ever properly jetted for your engine?

If you can buy or have access to a tool called a colourtune then I'd use this to get your mixture settings right. Otherwise get a professional to tune them for you. There are other ways of tuning twin carbys but they take along time and are not very accurate.

mate, smae thing happeneing to me.. my needle was ok, the problem was that
the jet was too far down, I took it to mini classic and got grieg to tune it
on his dyno, and it is now excelent

Hi,
Is a dyno tune worth the expense.
Thanks

for me i say yes yes and another yes

It sounds like float needle valve and seat are worn in the 1/2 carby. Float level is high, drowning the plugs.
I'd put a repair kit thru both carbs ...

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Hi,
Thanks Dr,
the carbies were rebuilt the same time as the motor, but I'll go and have a look at the float level.
Thanks

Hi,
Adjusted the float level and stopped the seepage in gasket of the fuel bowl. The car sounded a bit better but the 1&2 plugs are still dirty. Will have to check the mixture tomorrow. I think it is about 2/1/2 turns from the top.

Plugs are already fuel fouled probably. Either fit a couple of clean ones, or clean these by heating business end of plug with a gas torch. Let insulator end glow red for a second and the deposits will vanish like magic.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Hi,
Dr
I 'll buy another new set of plugs tomorrow. What is best spark plug for Premium Unleaded,
NGK- BP5ES or BP6ES
Thanks

Get the 5ESs if plugs are fouling now.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.