Working on a 70hp Triumph, 70473M. Someone put surface plugs in it and I need to change them but get conflicting numbers when I look up the Champion numbers. Anyone know the correct ones? Thanks
Use Champion QL77JC4 plugs gaped at either .030 or .040, whichever gap works for you.
One or the other gap may provide improved performance either at idle or full throttle... it varies from engine to engine for some reason. The smaller gap of .030 does provide longer spark plug life.
Thanks Joe. I was showing UL77V along with the L77JC4, superceded by the QL. I'll stick them in and call the guy to pick up his engine. Btw, Do you ever sleep? Appreciate all you do on this forum.
Thanks Joe. I was showing UL77V along with the L77JC4, superceded by the QL. I'll stick them in and call the guy to pick up his engine. Btw, Do you ever sleep? Appreciate all you do on this forum.
The UL77V plugs although they have a heat rating of 77 actually (like all surface gap plugs) are a cold running plug and prone to fouling. However they do for some reason work very well on various engines. Their main feature is an extremely long life. Personally I don't like them.
