SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Howardgaebel on October 20, 2020, 04:55:03 PM

Title: 454 timing issues
Post by: Howardgaebel on October 20, 2020, 04:55:03 PM

Have a mild built 454 in my jet boat , that I’ve never been able to get to run right in the high rpm. At idle it’s around 11 BTC around 3500 it’s at 35BTC but once you get in the higher rpms it keeps advancing and runs like it’s out of time. Is this the reason for locking out the advance? Do I lock it out and time it then use the start retard function on the box to get it to start ? If I do need to lock out the mechanical advance what rpm do a time it at and to what BTC thanks guys .

Title: Re: 454 timing issues
Post by: Howardgaebel on October 20, 2020, 04:59:03 PM

As it is now I can’t retard the timing enough to keep the boat running at idle when still keeping it in the right BTC range in the high rpm, I could be totally wrong about all this but any help is apprixiated.

Title: Re: 454 timing issues
Post by: Howardgaebel on October 20, 2020, 05:39:09 PM

I think I’m onto something I’m pretty sure I have the wrong springs In the mechanical advance not getting full advance until around 4500 I’ve read on here you need to be a full advance by 2300-3000 mabey changing the springs and re timing would help

Title: Re: 454 timing issues
Post by: Howardgaebel on October 20, 2020, 05:55:11 PM

Is this how my mechanical advance should be operating ?

Title: Re: 454 timing issues
Post by: OutofTouch on October 20, 2020, 08:04:19 PM

You are correct about having the wrong springs. Using the springs, set your advance timing to be all in at the rpm that your boat has come on plane, probably round 3000 rpm. If you have a speed shop locally, see if they have a distributor machine and have it set up correctly. They will be able to set it up for both your initial timing and full advance.

Title: Re: 454 timing issues
Post by: Howardgaebel on October 21, 2020, 05:19:03 AM

Thanks out of touch so around 3000rpm I should be around 32-38btc ? Or start at 30 and work my way up? Until the boat loses performance then dial back? Do I need a shop to do it I have a timing light can I adjust on the lake or do I need a shop for another reason?

Title: Re: 454 timing issues
Post by: Howardgaebel on October 21, 2020, 05:26:13 AM

I also have a spring and advance stop kit that came with the distributor

Title: Re: 454 timing issues
Post by: Rogers57x on December 23, 2020, 12:15:07 PM

Just my 2 cents , I have the same msd set up like you have I have locked out the distributor and used the retard on the box set at 34 degrees btc runs awsome  to 6500rpm no problem and leaves the line at 2500 then 4000 then hard to 6500 my motor is a 489 big chev with aluminum square port heads 10 to 1 comp solid roller cam 800 lift  tunnel rammed fossil fuel sucking machine love it my 2 cents😎

Title: Re: 454 timing issues
Post by: 96Laveycraft21Xt on December 29, 2020, 03:02:37 PM

you need to find out what your timing is doing.

shoot the timing at 4000, 4500 etc and then you will know if it is still advancing.  list your spring colors so we can help get yours correct.