Triumph Repair: Metering Needle, triumph spitfire mk 4, triumph spitfire mk

Question
Jim,
1973 Triumph Spitfire Mk. 4 1500 Zenith Stromberg carb.
Im getting gas in my oil, I suspect the metering needle? Car runs good otherwise. There is no oil in damper also. Should I add oil to the damper and try it before changing the needle or would you change the needle? Also what type of oil should I use in the damper? Can the needle be changed without removing the carb? and do I need the special needle adj. tool?
Cheers,
Richard
Richard  

Answer
Richard,

There are two possible ways to get gasoline in the oil on a Triumph.  The first would be if the needle valve in the float chamber is improperly adjusted, allowing gasoline to overflow via the jet into the manifold and into the cylinders.

The second possibility is that the fuel pump diaphram is leaking.  The fuel pump is on the driver side of the engine (US models!! ) near the back end of the block.  The fuel pump has a lever arm that is driven off an eccentric on the camshaft.  So, if the diaphram in the pump is leaking, the gas will go straight into the oil sump.

Adjusting the mixture metering need will not fix the problem.  You should have oil in the damper though, it controls the mixture for proper running.

As to the oil to use in the damper... there's quite a bit of debate.  One manual I've seen recommends topping it up with the same oil as the engine (without the gasoline in it, of course!).  Other recommendations include ATF, 3-in-1 oil, etc.  

Just try using normal engine oil.. and get the car running.

Fix the gasoline leak, and make sure everything is adjusted properly with the ignition before playing with the mixture needle and damper oils.

Then it's time to play.


Cheers,

Jim