120 merc hitting on 2 cyl?

[freak007]

Re: 120 merc hitting on 2 cyl?

I am 99% certain that the lifter pre-load spec for that engine is 0 lash + 1 turn... the easiest way for you to get that follows:

with the engine running (valve cover off) slowly tighten each rocker until the chatter stops... if the engine starts to run rough when you are tightening the rockers down, you are probably inducing excessive pre-load (IE back the nut you are tightening off). once you have it quiet redo each rocker by backing it off to chatter... then tightening to 0 lash (no chatter) + 1 full turn... it will be a little messy, but this is the quickest and easiest way to do it...

Once the pre-load is properly set you will probably have to reset your idle and ignition timing...

 

[imastevesmith]

Re: 120 merc hitting on 2 cyl?

Loosened rockers back up, took the lash out, & took it 1 turn, Started it up & adjusted the idle now she purrs like a kitten!!!! THANK YOU to everyone who helped me along this new path. All your help is greatly appreciated and there will be a smiling 13 year old on ski's with his grandparents watching him for the first time thanks to you!