i have a 1982 7.5 h.p 2 stroke, model # E8RCNR don't know what the R stands for. i bought new plugs but when i matched them up to the repair manual they are different numbers , the plugs i have in there are champion QL77JC4 and the manual calls for L7734, Iis there any differece between the two? i did use the QL# last year and there was no problem.... anyone now the gap of these plugs? can't find it in the book....thanks