I believe he knows and the "What ???" is more like "What the f*k answer is that ?"

I'm just more direct !

LOL.

BUP yes that is what I was trying to say, thank you. I was told that the ECM advances the timing until it detects knock to check the knock sensor and then retards timing a few degrees. If it does not detect knock it believes that the knock sensor is defective and retards timing to a safe amount. Because these are low compression engines, 93 octane fuel will not knock at the pre-programmed timing levels. If I have been misinformed, I apologize for suggesting that he try lower octane fuel to see if that resolved his problem. 87 octane has always worked for me and I do check with my Rinda Scan Tool.

Well I have heard that statement before about using premium will not let the knock sensor do its job, but I suspect that's not correct at all - doesn't even seem realistic.

I have used premium my whole life so I don't worry runnin it, and just for cheap insurance when things aren't exactly right. I know most people CAN run regular, but I also see many rebuilt motors from detonation damage and they sometimes wonder what happened. I've even seen it happen twice to one guy and finally he took my word for it to use premium as he didn't really look after his stuff. Anyway as long as you live and learn.

Ok one more question. The book says to install the knock sensor at 16 - 20ft lbs and with NO SEALER, nothing. I'm just not used to installing any threads on a boat without at least grease.

Do you know if this is really necessary to put nothing at all????

BUP I got a Mallory 9-33500 sensor for both motors. Mallory package says it replaces Merc 805544T. I did have the wrong BWD sensor though.

TRASH your probably right, it may be close to normal. I've always thought a v8 can run at least 30, or maybe 32 or so, even at WOT as long as tuned right and good gas. It may not be less than the factory 415hp rating, but WOULDN'T IT GAIN SUBSTANTIAL HP AT 30/32 ??

Thanks for all ya'lls information.

Well that's what I told you on the phone and to triple check it from post # 17. I believe you had the wrong knock sensor to begin with. The BWD book shows the wrong sensor to, but I would not have known until I seen the pic of it as you sent. Did you get my pics what the book listed from BWD ?

yes I got your pic. thanks. I got the merc 805544T which Palmer stocked as the Mallory 9-33500. Do you suggest installing it with the threads completely dry as the manual suggest? I sure like to grease or seal threads for corrosion.

Did you ever find the timing chart ?

Kurt I haven't even looked in the manual as of yet but I do not think its posted in there anyways, Also I can not believe I am drawing a black here about the timing table here.

I went back to read your posts - I am lost from your post # 4 and then your post # 6 you mention two different timing specs at 4800 / WOT ?

We talked about if it have Teflon tape on them installed ? You said at first but when you changed them out recently - you said you put something else on the threads. I would clean out the engine block threads with a stiff wire brush and or the correct tap with WD - 40.

Maybe a thin coat of dielectric grease on the threads. MERC says - not to use anything on the KS threads.

yea one post i said 19, the other posts I said 20/22. But both are close and that is at WOT, high map. They get around 20+/- one degree. as its hard to read when your running wot on the water. The both do run high timing - about 34 - cruising mid range at lower map. I sure would like a timing table for this 502 if you ever find it.

KS works off of a change in harmonic frequency, if something is used on the threads this can cause a dampening effect. Engine running WOT an the ever so slight ping may not be sensed right away if something is on the threads, like putting a cloth over a microphone.

Whats on these threads is all you need, like stated before dont put anything else on it