Hello my name is Alex and I am in Lewisburg Tennessee seeing if anyone on here has a used or old stock 15248T01 timing module that I can buy to try out on my 502 in my Checkmate. I'd like to try one out vs the 20 degree module to see if anything is to be gained.

That would be a V8-24 module https://www.marineengine.com/newpart...um=MER15248T01
What module do you currently have??

I have the 20 degree, its the V8-20. I have read the 24 degree is a decent beginner basic improvement over what the engines came with in 1990.

Here are the advance curves. You would be best off with a V8-HP and next choice would be a V8-24

I found this chart on this site, what makes the V8HP better, is 24 degrees total too much, its a 502 mag, factory, Rochester carb I believe, I had the Carb rebuilt and have replaced the coil. Oil stays clear all year round, uses absolutely no oil and has supposedly 525 hours.. Though it may have been refreshed in the past 31 years. Boat runs very well, but have been doing some research and am curious about slight performance gains that would help it get on plane much better. I am pretty much a novice here so what makes the HP better than the 24, and would I adjust my base timing to allow for more total timing with V8HP module? Or not mess with it at all?

You set your total timing to 32* either way. You just reduce timing at idle to 8* with the V8-24.
The V8-HP brings timing in faster and will give better throttle response.

Really appreciate the advice Griff, I found an HPV8 17316A1 module on Perfprotech, unless a vendor on here has one that wants to speak up I guess that seems to be my best route. Thank you very much for the info again!

The V8-HP modules are discontinued from Merc, so if you can find a new one, grab it.

Were you able to find the V8-HP ??

i think most use the v-6 modual that has 14 advance you set the same top timing but it idles with more timing most engines love that its a bit cleaner and smoother its the reason we run the delco voyager est system on fishing boats the smooth idle stops shreading the flex plate