de-cell knock...05-150 johnson

[looper power]

I did a search and really no answers. I tried slowing down off the throttle but sometimes it still knocks. a couple of times it is loud. I am still breaking the engine in. got about 5hrs on it. I use 89 octane. it does sneeze at idle sometimes. but my hands are tied with the warranty. what can I do or check to make sure I'm not hurting anything while I'm breaking it in?

 

[Dhadley]

Re: de-cell knock...05-150 johnson

Hummm...why are you using 89 octane?<br /><br />We assume a carb'd motor since you mention a sneeze. Right?<br /><br />What spark plugs?

 

[looper power]

Re: de-cell knock...05-150 johnson

yes a carb. plugs are ql78yc. too much octane?

 

[ondarvr]

Re: de-cell knock...05-150 johnson

I wouldn't touch it, just take it back to the dealer and let them handle it. If you do anthing they blame it on you, then they're off the hook.

 

[Dhadley]

Re: de-cell knock...05-150 johnson

The de-cell knock in a 60* is not uncommon and hurts nothing. You can try some cooler plugs like the QL77JC4's. Sometimes that helps. If you chop the throttle hard from wot or near wot you can push the primer. That usually stops the noise. I'd stick to the 87 octane that's recommended.<br /><br />The other thing is the "sneeze". It shouldn't do that. Let the dealer fix that under warranty.

 

[looper power]

Re: de-cell knock...05-150 johnson

thanks Dhadley, with the jc4's should they be gapped to 030 or 040? same with yc's. I do have the service man.it does say 030,but my other loopers did idle better when gapped at 040. just wondering. thanks