Re: Spark plugs for 175 Johno 1999
The factory recommended plug is the Champion QL78YC gapped at .030". It can be widely purchased for around $3.50 each. There is no other recommended plug for normal use. The QL77JC4 and the QL16V can be used but do not give as good an idle or low speed operation as the extended nose QL78YC does.