contradicting engine specs on spark arrestors
 

Both of these are 1988 mercruiser racing 320 EFI 5.7 liter bravos

Both motors look identical. both flame arestors the same , decals on them the same except the stb one says timing 8* btdc and the port 12* (they may not be on the correct side)
the manual oem mercruiser says 12*
I also have th eoriginal paperwork from Formula test tank inspection on 8/31/87 and both motors had timing at 12* btdc
serial no on motors
stbd-b858846 port-b858853

is this a typo or correct? if correct why?
Also I just happened to look into the stb valve cover where you pour oil into and there are roller tip rockers. didnt check the port side yet
thanks

Are the ignition modules the same or different? V8-24, V8-20 etc.?

same

What ecm is on them, being 88's a mefi 1 ??

ill have to look, they both have dacals on them saying;

5.7 litre efi designed and built by mercury marine performance,
where else do i look?
thx

I didn't even realize merc offered efi then in sbc or bbc.

I put a 0 in front of your serial # on Merc's site,

http://www.mercruiserparts.com/320-e...8-1989-0b15760


It doesn't appear to have an ecm

Might want to set total timing where you want it. Then let the idle timing fall wherever.

it does , go to exhaust manifold on that parts diagrams and look at # 17
11350A8 --------E.F.I. CONTROL BOX ASSEMBLY nla

set them both at 12.

Yeah, thanks. Thats what I plan on doing. Its still too cold here to take the boats out for a rip. Maybe next week...In the meantime Im keeping it inside going through everything on this one for the first time. (purchased in NY 4 weeks ago)
thanks for the input

MEFI was not around in the 80's. This has a ECU like what the Merc outboards had . Diacom nor a Merc DDT will scan this engine. Its a special Merc diagnostic tool that reads the ECU. I have it and the manual that goes along with it. It is nothing like the current marine scan tools. There is most likely Service Bulletins on this for the timing differences - you need to post your engine serial numbers.

hi, i did post them
here they are again
serial no on motors
stbd-b858846 port-b858853

thanks

1986 was 8 deg btdc mercruiser changed all initial timing to 12 deg btdc. Everything was to be changed in owner manuals and service manauls and on stickers on the engines. This took place oct 1986 forward. As i recalled there was a service bulletin all about it actually 3 on timing and a bunch more service bulletins for the 320 efi

Wow. cool thanks for the reply/info. Do you know how I can get any of these service bullitins?
thanks

Sorry I have been super busy as you know all Merc dealers will have this and can even pull them up thru Mercnet.
Back in the day they were sent to us as they became available thru Merc in paper format. I have a huge binder full of them from the 80's and 90's till early 2000's as when Merc and other OEM's were changing directions from paper to internet based info

My binders are in storage - Most of my work is 2004 to brand new boats so I put alot of this older stuff in storage. Most likely when I can take break could dig out the huge binder and go thru all the related material for the 320 EFI. There was alot of info for diagnostics as well in the late 80's for the 320 EFI. As it stands currently. I am booked till June 1 so really can not put a timeframe looking for all this info. Sorry about that but you know how it is being in the biz, have to get down and make the donuts as its that time of the year.

Thanks for the reply. Dont worry about digging out the old bullitins. Not needed at this point, thank you though for the info. hopefully wont need later lol