1971 650 bonny. oil in frame. just got the bike and noticed that the dipstick is gone or maybe never was one. when looking in frame, where should the oil level be at? should it be visible? again my first triumph.
Yeah, you should be able to see it. They used a dipstick attached to the fill cap with a little chain - most broke off. Might be a good idea to change oil and note exactly where the level is with the specified amount put in.
Also, try all this on the vintage forum - a lot of guys there with the older, more problematic Triumphs.