9.8 Mercury Pinging

Recently my 9.8 merc has developed a pinging noise caused by pre-detonation. When I have it at 3/4 throttle and it is laboring the hardest trying to get my 12ft v-hull on plane is when it occurs, then when it planes out it stops. I have read that 75 percent of the time it is caused by overheating. It pumps water well and stays relatively cool to the touch so I can rule that out. It can also be cause by lack of gas to the cylinders but I adjusted the carb to give it more gas and that didn't help either. I have been told that I need a higher octane gas or that my timing is off. If anyone has had a similiar problem and knows how to solve it your knowledge would be greatly appreciated! Thanks

Re: 9.8 Mercury Pinging

I would first do a decarb. Carbon buildup is a common cause of pinging.

Then I would reset the timing, by the book.

Re: 9.8 Mercury Pinging

The one thing I haven't done is cleaned the carb, so I was planning on doing that anyway. Hopefully That will do it so I won't have to reset the timing. Do you know of anyway I could find out how to set the timing without buying the manual? Thanks for your help, it is much appreciated.