^^^^ Thanks for posting your experience as to what I am talking about. I not only will say I agree but 110% agree. Also injectors are electrical and mechanical devices so sometimes even new injectors have problems or do not flow like the one next to it.

Also there is many knock offs in the market place, Most do not even flow the same nor the same spray patterns. You have to watch what you buy. Even though they might say Delphi or Bosch on the ad for selling injectors, that means nothing currently. There is way to many copy cat injectors on the market and on ebay. I would say that 75 to 80 % that are on ebay are knock offs especially cheaper priced injectors.

I only buy injectors thru 2 known distributors in the USA who only sell 100 % OEM fuel injectors and basket filters. The prices are not the cheapest but I have had 0 problems and what to keep that way.

If you want me to test and flow test your EFI 320 fuel injectors and clean them up I will BUT IMHO - 30 year old fuel injectors really are not the best option currently. I really feel that I would be taking your money. The service is 20 to 25 bucks per injector depending how bad they are. I always install new basket filers regardless. I will leave this up to you. If they were mine I would buy the most current offerings. No offense just saying.

Let me say this, for older injectors it is best to warm up your flow testing fluid and run the injector(s) for 30 mins straight - let the injector heat up as well to see if it will short out or the spray pattern changes however. This is very common and especially with GM / Rochester Multec injectors. Multec 1 injectors are the worst for just dying out after they build heat. I do not even bother anymore with testing Multec 1 fuel injectors - I buy a cross replacement Bosch and sell that to the end user.

If I recall correctly the Merc EFI 320 - 1987 thru 1989 used Bosch injectors and Bosch fuel pump

I've been down this road with the 320's. I'll check injectors to see what was installed as replacements. If memory serves me the fuel system Merc used was out of a 928 Porsche.
The Merc NLA injectors, fuel pumps and regulators were easily sourced.

Cool, thank you,thank you. this is exactly what I was looking for. Im waiting to see what you find!

Okay here is what we did today, we took off the fuel water seperator filters threw them in the trash, took 2 new ones filled them with TECHRON fuel injector cleaner concentrate, screwed them on,dumped 2 more into the 50 gallons of fuel that are in the tank and ran the motors for 15 minutes. no more rich eye burning fumes and they both seemed to run much better on the hose. basically both ran mint. so until i get it out on the lake thats it. too many other projects to finish before everyone uncovers thier boats up here in mass, but still want info that sonicss can dig up..

How does that boat run? I had one with 330 454s and ran 65. I always wondered how they got 320 horse out of them over the base 260/270 horse. Seems like a stretch for those stock heads even with more cam.

They had a Lingenfelter designed tunnel ram too, right ?

I didn't realize it had an intake like that. Probably turning above 5k you get some good ram effect. Still those heads were pretty limiting.

If I remember right, those motors where some pretty serious cash + some where connected to an Alpha SS...so...wonder if somethings was done to the heads or something else ? I can't remember. Hmmmm.

The SS drive was 2 inches shorter as well

I can see BUP's point of view. Since marine injections are virtually all closed loop, there is no way for the computer to know a given injector is flowing too little fuel and creating a lean condition. In the automotive world, the O2 sensor tells the ECU whether or not the fuel curve is right. In the marine world the ECU is assuming everything is in spec.