TECH TIPS & MAINTEANANCE 3.4L MARINER

[CARLOS]

HAS ANYONE OF YOU ANY INFORMATION ABOUT MY OLD BUT STRONG COSWORTH 3.4L 1990 275 MARINER?(ODO33311)<br />MY ENGINE HAS AT LEAST 600 HOURS AND I´M WORRY ABOUT DECARB PROCEDURE, REPLACE LOWER OIL UNIT PERIOD (ALSO TYPE OF OIL),COMPRESSION SPECIFICATION?. I´VE BOUGHT USED...<br />ONLY I NEED IS SOME TECHTIPS...CAN I FIND BY INTERNET? SHOP MANUAL? WHERE CAN I BUY?<br />IN MY COUNTRY NOBODY WANTS TO HELP ME BECAUSE OLD ENGINE AND ALSO POOR ENGINE REPUTATION! <br />NOBODY WANTS TO TOUCH IT! NO SPARE PARTS!!!<br />CAN I USE PARTS FROM 200/225/250 FOR MY ENGINE?<br />I´VE ASKED BY THE WORLD BUT FEW PEOPLE KNOWS THIS ENGINE VERY WELL<br />I HAVE TO DO MYSELF AND I LOVE THIS ENGINE.I WANT TO KEEP IT ALIVE!!!<br />PLEASE REPLY ME. NICE FORUM...VERY INTERESTING<br />REGARDS<br />CARLOS<br />MITSUBISHI MOTORS MECHANIC<br />VENEZUELA

 

[rickdb1boat]

Re: TECH TIPS & MAINTEANANCE 3.4L MARINER

CARLOS<br />Did you ever find out about the engine running too cold? As I don't know what type/brand products you have available to you, I will just give you some generic answers. All the products can be found at any Marine shop. As for the lower unit lube, you want to use a "High Viscosity" lower unit lubricant. Change it once a year. When you do change it, note the color of the oil. If it looks milky, you may have water in the lower unit, which would require further investigation. If it's black or fairly clear, that's OK. As for the compression, you would want it to be at least 100 PSI on each cylinder and all the cylinders to be within a 10% reading of each other. As for a Manual, you should be able to order one from the site at the bottom left of this page or a factory one from the link below. As for the engines being compatable, I'm not sure on that one. I'm betting that many parts are interchangable, though. The other link is a guide to parts and diagrams, which is as close to a Manual as I can find online. Maybe others will have some other help for you, but I would get the Manual as soon as you can, as it will explain all the procedures you need to do to keep your engine running good.<br /><br /> Decarb <br /><br /> Manual <br /><br /> Parts and Diagrams

 

[Kenny Bush]

Re: TECH TIPS & MAINTEANANCE 3.4L MARINER

Carlos, I saw your "help Wanted". I had the same problem in Texas. The largest mercury dealer in the Dallas area did not even have a manual. The Clymer and Seloc manuals are very broad in their information, but I would get one of them anyway. I had to order a manual from Mercury which cost $300.00 US. The Mercury is very detailed.......I have rebuilt one, and it cost me about $3000.00 US just in parts. I love the engine because of its massive power, and it has been a very reliable motor for about 12 years. As for parts, all of machined parts are unique only to the 3.4l, but some of the boltons can be used from the smaller V6's(coils, wires, WMH carbs, Power packs, ECT.) Run a compression check on the motor and post results. I do not know why it is so rough at the lower RPM range. With 6 Carbs and 24 rows of reeds, it is sometimes hard to synchronize. CHeck it out and get back with me....Goodluck...BushCat

 

[CARLOS]

Re: TECH TIPS & MAINTEANANCE 3.4L MARINER

MANY THANKS BUSHCAT & RICK,<br /><br />MY GOAL IS TO KEEP THIS ENGINE ALIVE! IT SOUND STRONGS AND IT IS IN GOOD CONDITIONS. <br />ALWAYS I USED UNDER 3500-3800 RPM AND GOOD SPEED ABOUT 32 KNOTS. ALSO I ADD ADDITIVE MOTORKOTE100 INTO GASOLINE FOR ADDITIONAL EXTRA LUBRICATION.<br />ANYWAY, MANY THANKS FOR YOUR HELP AND KEEP IN CONTACT.<br />CARLOS

 

[Kenny Bush]

Re: TECH TIPS & MAINTEANANCE 3.4L MARINER

Carlos, use that motor to its full RPM range. About 4400 RPM's. It keeps the motor clean. You do not need to run full throttle, but every couple of hours, "Air it Out" for a few minutes. I also decarb mine about every 100 hours, and it seems to stay clean. My motor has always run rich, so I lean out the gas a little bit. I have this 300 on a 23' Chris Craft Center Console, and it runs about 62 MPH. I get excellent fuel economy at about 45 MPH, or 3600 RPM's. I have a 23 pitch "Chopper" style prop. I have spent about 1000 hours in this boat and it is one of my favorites in my fleet. You can find a few parts motors on EBAY.Com . Anyway, Check your compression and post results. My rebuilt motor reads 125 lbs on 5 cylinders, and 121 on 1. Goodluck.....BushCat