[cb400tcol]

Need some feedback from this group that has been helpful with my CB400.
I bought a nice but neglected 1974 CB360 and have gotten it running with a good carb clean, new battery and points/timing adjustment. Ran OK -drove 5-6 miles, on return, heard the top end was noisy with clattering etc so next day thought I would go through tune ritual again to add valve adjustment to the mix/ this time with first doing cam chain tension adjustment- but when I loosened the cam chain adjustment bolt and lock bolt (that were overtight) they just turned around stripped. Pulled out the tension adjustment bolt and there was metal from the female threads loose on the bolt. Not sure what to do next- I re-inserted the stripped bolt then tried to re-start the bike to see impact of this situation and the bike revved right up to 7-8K rpm’s with no throttle opening by hand!!!- so I shut it down to avoid worst happening.

Help, what am I up against with this issue, how to fix the chain tensioner female threads to get this back to an adjustable state to move forward with project. I am hoping that just removing cylinder head will allow access to what ails this without whole tear down? Would this chain adjuster issue cause the engine to rev up that high???
Thanks to any support I can get from the forum!!!!!!

 

[spirograph]

Tensioner shouldn’t make it run high, I don’t think. Does the tensioner locking bolt still seat into the bolt hole snugly? I wouldn’t panic about a little thread loss (though I’d be more careful). You can access the tensioner mechanism without removing the top end though - pull the engine, get a mik crate, flip it upside down and take the lower case off.

 

[cb400tcol]

Thanks, panic is close to where I am, does not seem to go back in snugly-maybe I could try same length bolt with courser thread or one mm larger thread to go back in tighter??

On the high rev’s, I did mess with the throttle cable when putting back together because when I moved the handlebars side to side heard rev’s increase to 4-5K. Then noticed that the idle speed adjuster knob was pulled out from where the springed end goes and was not sure where to re-inset-could that adjuster go out of whack and increase the rev’s that high with no hand throttle applied at all???

Scratching my head on two fronts at the same time when things were so close to sorted out!!!
JH

 

[spirograph]

What am I talking about - I have a spare 360 case in my scrap metal bin, the threads on that socket should be fine. Let me look at it tomorrow; if the thing isn’t dinged up from being in the spare parts bin, I’d give it to you for $20 and shipping. There’s no problem with different case halves, and you can swap em without taking apart the top end.

For the high idle, I’d start with ensuring the throttle cable is as free as it can be - if turning the bars changes your idle speed, that’s definitely it. Is your cable slightly loose at the carb side? FSM calls for 1/8 turn of free play in the cable when at 0 throttle, and you’ll want it to be on the carb side. Other things that can cause high idle are vacuum leaks and carb sync, so once you’ve got it manageable, check for leaks with WD-40, then reset the idle air screws and vacuum sync the carbs.