August 5, 20179 yr The bike is together, and now has a bit of ride time around the yard. No issues, and very pleased with it. When I went to buy spark plugs weeks ago, I thought I got the correct one. I searched the internet quickly and found recommendations from heat range 8 to 5. I read that BP6ES was correct, and it did cross reference to the ages old Champion N9YC I removed. I now suspect, having seen other references to BP7ES being correct. I have pretty much ruled out the heat range 5 and 8. So, for a 1973 MAR 250, is it a NGK BP6ES or BP7ES? Ready to get the jetting fully sorted out, and prefer to do it on the truly correct plug.
August 5, 20179 yr Champion N-9Y or N4G Bosch W-200 T30 NGK BP-7E Auto-Lite AG-32 AC C42N Lodge CLNY There is no such thing as a truly correct plug, it depends on the ambient temperature and the type of use.
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.