The engine manual says the spark plug gap is 0.4mm -0.5mm
For low ambient temperature they recommend a gap of 0.3 mm- 0.4mm
Limbach changed to automotive style plugs after Eyquem ceased production.
They were a modern style auto plug with a conductor ring below the electrode and 3 earth legs.
Later they changed to 2 earth legs.
They are not shieled but do have capacitors built in to reduce radio interference.
The plugs use a different ignition harness which is shielded.
After a couple of years some customer complained of interference and the numbers were noticeable.
I have not seen that problem here in oz and have sold many new style harnesses and plugs with good feedback.
The result was that Limbach reissued the old style harness again and sourced shielded double earth style plugs.
So you have a choice. Both types of plugs are branded “Limbach” and of course are approved as are the harnesses.
The liquid cooled versions of the L2400 use a completely different plug. Different heat range.
I have a lot of the new style auto type plugs and 3 of the fully shielded. Odd number I realize.
Hope that clears things up.
It is always best to refer to the approved data from the manufacturer. It is available on the Limbach website in the bulletins.
Cheers.
Nige.
I have used for years NGK B6HS and are, available at the local corner store in Australia. They are conventional car plugs and good for 150hours. I usually replace once a year as they are so cheap.
I use there washer plus the CHT copper ring as this prevents the plugs sticking thru too much in head. I use MGL digital CHT and monotor all 4 cylinders. Great engine insurace policy.
I gap at 0.48mm as gaps only get bigger with time. The gap is supposed to be 0.5mm
The Limbach plugs are good for 500hrs I believe and are very good.
No answer. It is Saturday afternoon on this side of the date line.
I will give them a call on Monday morning.
hi Rob,
one wonders if they actually have them...the pictured plugs have an incompatible plug/harness interface, ?????????????????????? Maybe you could ring them and find out 🤤 Pretty please, with sugar on top.
Remember, the original harness had a wb4a compatible interconnect which screws on (10nm torque, 19mm crows foot spanner and a 11mm open end spanner to prevent lead twisting) not a push on nipple pincher / terminal nut.
there are 4 for sale on eBay by a German profiteer for 220 euros. I had a big box full of them but they sold out quickly. looks like you'll have to buy a new slick harness to go with the new style plugs.$$$$
I am currently on my last four wb4a'sbefore I change over.
Here is the link to the Limbach service bulletin when they changed from the Bosch WB4A to Eyquem plugs.
....and then they changed to their own Limbach branded plugs.
I suspect the changes were for commercial rather than technical reasons.
Oops. The Bosch number is WB4A that I have.
My Eyquem A755 spark plugs are aging about the same as me. I am looking for a substitute. I have some Bosch EBC G7. Are they suitable? Does someone have a suggestion for replacements?
