Can you please verify my total spark advance?

[milkyway]

1998 Merc 5.0L 220HP Thunderbolt V Initial Timing is 10BTDC

Using an advanced timing light, here are the readings in degrees with the specified rpm.

2500rpm---15degs.
3500rpm---24degs.
4000rpm---27degs.

Merc manual states that total advance for this engine with thunderbolt 4 ( for comparative) and which has a module advance of 22 and initial of 8 degs. should be as follows:

2500rpm---15to19 degs ( total spark minus initial)
3500rpm---20to23 deg. (total spark minus initial)

It seems that my advanced timing is below specifications.
Your comments and expertise are appreciated.

 

[Don S]

Re: Can you please verify my total spark advance?

Put your tools away and go boating, you're fine.

 

[milkyway]

Re: Can you please verify my total spark advance?

Shoot.. Now I still have to figure out why my top speed is ony 35mph.

Thank you.

 

[Don S]

Re: Can you please verify my total spark advance?

You have a 23' Maxim with only a 5.0L engine. Who knows how much stuff you have packed on it. But if you are expecting to get what the advertisements say, my suggestion would be to forget it.

 

[milkyway]

Re: Can you please verify my total spark advance?

I just found and read again the surveyor's report. In 2004 when the survey was done, top speed on his gps was 37mph at 4400 rpm. I guess this is all I will get from the engine.

Thanks.

 

[Don S]

Re: Can you please verify my total spark advance?

Was that 37 mph with the wind and current?

Like I said, go boating.
Might want to drop down a bit in prop pitch if you are now lower than that 4400, puts a lot of extra strain on the engine to be over propped. You should be in the 4600 rpm range for optimum with your normal load on the boat. Fuel, water, people, etc.

 

[milkyway]

Re: Can you please verify my total spark advance?

Thanks. I am going back to 17 pitch and do more boating than worrying.