Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
I can see how the bolt came out if you didn't put locktite on it but I can't fathom out how the dowel got involved in the failure 🤔🤔🤔
Quote from: Nurse Julie on December 26, 2023, 11:12:30 PMI can see how the bolt came out if you didn't put locktite on it but I can't fathom out how the dowel got involved in the failure 🤔🤔🤔Julie, maybe Loctite is something you recommend, but there's no mention of that in the official Honda CB400F shop manual over in Aladdin's cave. I built a fair few of those Honda engines during my years in the trade and never had fully tightened cam sprocket bolts come loose. Bit of bad luck for Sean tho, hope he gets it sorted out.
TBH I suspect the cam sprocket bolt was never tightened rather than came loose, you tend to fit one but not tighten it, just in case it locks the sprocket out of alignment for the other bolt, spin the engine until the other comes up so you can fit that and then forget you haven't torqued up the first one and move onto something else, anything can cause this, someone speaks to you, a phone call, just something that breaks your concentration, easily done.
That's bad luck Sean - I've generally ensured that the dowels are on the fixed surface first so they can't drop out. It has meant I have had to replace a few as they chewed up a tad on extraction.As has been said any unaccounted for big lumps should drop down into the sump - goes without saying to change the oil filter. Have you fitted a magnetic sump plug might be worth it as belt & braces.