How do I check RPM's

[Minnesota Ernie]

How do you check the RPM on a Johnson 70HP when it doesn't have a distributor cap? My manual that came with the Dwell/tach meter only specifies connecting to a distributor. Also, what should my 1980 70HP Johnson be idling at?

 

[Bob_VT]

Re: How do I check RPM's

Purchase a tachometer for the outboard or purchase a "Tint Tach" search on this site for more info. Your idle under pressure not on water muffs should be right around 700 - 900 rpms.<br /><br />Bob