Author Topic: timing chain adjustment 1978  (Read 976 times)

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Jeb

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timing chain adjustment 1978
« on: November 12, 2006, 07:40:28 PM »
I am new to the board and new to the Honda CB.  I just sold a '79 Guzzi and picked up a '78 CB750K.  The bike is in great condition and runs well but it makes a lot of noise when it idles.  I suspect the timing chain.  I searched this forum and read some of the posts about timing chains.  Apprently the way to adjust chains changed over the years.  I tried the method of self adjustment listed in the owner's manual and there was no change.  Could someone run through this seemingly simple procedure for me.  Also how should I check the tensioner on this model?  Thanks

Offline mcpuffett

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Re: timing chain adjustment 1978
« Reply #1 on: November 13, 2006, 01:48:34 AM »
noise at idle can be because your carbs need balancing , does the noise disappear if you pull the clutch in or lift the revs ? ,    mick.
Honda cb750 F1 76' and cb750 KO 1970,   suzuki GT750A 1976  Honda VTX 1300 2006, Lancaster England.

Jeb

  • Guest
Re: timing chain adjustment 1978
« Reply #2 on: November 13, 2006, 06:17:07 AM »
Mick,
Thanks for the reply.  The noise disappears w/ higher revs.  It does not disappear when the clutch is pulled in.  The bike is so quite on the road I can only hear the wind.  I do believe the carbs could use to be adjusted.  The left inside cylinder does not have as strong exhuast pressure as the rest at an idle.  I do not believe I could adjust 4 carbs myself.  Could anyone on this board recommend a mechanic in Atlanta?  Thanks

eldar

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Re: timing chain adjustment 1978
« Reply #3 on: November 13, 2006, 12:15:38 PM »
Well jeb, I understand about the carb part. The cam chain is pretty simple though.

You first want to remove the adjusting unit and remove the plunger and spring and clean everything. Oil gets in here and it gums up after a few years. Put it back together and remount it on the engine.

Set engine to manual specs and adjust normally then. Should be no problems then.

Jeb

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Re: timing chain adjustment 1978
« Reply #4 on: November 13, 2006, 12:53:45 PM »
eldar, Master of the K8 Thunder,

Thanks for the info.  I'll take your advice and clean up the adjusting unit this weekend or sooner.  My brother is a good mechanic and his labor is the right price - in fact I usually get free beer and cigars when I go over to his house too.   Do the carbs have a certain setting like 1 and 1/2 turns out so I'll have a starting point?  Is there a website like K8 carb adjustment for beginners.  Thanks again

eldar

  • Guest
Re: timing chain adjustment 1978
« Reply #5 on: November 13, 2006, 01:21:56 PM »
The idle screws are fuel screws. This is very important. Turning these out makes the mix richer, in is leaner. The 76 and earlier bikes had air screws which worked opposite. On the 78K 1.5 turns is base starting point.

 

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