Engine stall and cranking in a Mercruiser alpha 1 4.3l

I recently bought a used 1998 Stingray with a Mercruiser Alpha 1 4.3L engine with low hours. I am not sure how long it had sat up before I bought the boat. The engine ran fine and became smoother after running it for a while during the test drive. When I put in at our lake, it would idle fine, but would not take the gas when in gear. Took the boat to a service mechanic and had new carborator kit put in and all fluids changed. My problem now is that the engine will crank up an idle fine and go into gear and go but, after returning and shuting engine off, re-starting is a problem. Semi experts have told me it is bad fuel in the line, fuel filter, and fuel pump. I ran the old gas down to 1/8 tank and add fresh gas with a fuel stablerizer and that seems to help, but I am still having problems with consistant starting without stalling out. Should I replace the fuel/water filter? Where is the fuel pump on this type engine? Thank you for your help

Re: Engine stall and cranking in a Mercruiser alpha 1 4.3l

Welcome to iboats <br />Replace the fuel water filter by all means....<br />The mech. should have done that with the service!....<br />I doubt if you have a bad pump <br /> Try this! <br />Hope this helps!<br />I'd bet money your separator has water in it, pour it into a suitable clear container & have a look ......JK<br />Whoops, you want manual #18, click on "Main Menu to get there....JK

Re: Engine stall and cranking in a Mercruiser alpha 1 4.3l

Thank you for your reply. I ordered a new fuel water seperator today. My next question is where is the fuel filter on the carburetor and should this be checked and changed? This is my first non-outboard motor and I am going through a huge learning curve. What is a normal range for oil pressure and temp on the console gauge? My engine temp stays pretty much in the middle (165), but the oil pressure will go all the way to the right (80 psi) when the RPM's are 4800+ then will move 1/4 of the way back to the left (60 psi)after a few minuets or if the RPM's are reduced.

Re: Engine stall and cranking in a Mercruiser alpha 1 4.3l

i gotta warn you that I/O is not gonna run at 4800 RPM all day like your outboard and have a long and happy life <br /><br />I dont what weight oil your useing BUT 80 sounds high ?<br /><br /> http://www.boatfix.com/merc/Servmanl/18/18covr2.pdf <br /><br />manual 18 is close BUT may not cover your motor exactly<br /><br /><br />tommays

Re: Engine stall and cranking in a Mercruiser alpha 1 4.3l

Thank you. I do not like to run the engine at 4800 rpm for to long. Way to much speed for what we like to do. I was concerned that the oil pressure may be to high. I looked it up in the manual and at 2500-3500 rpms it seems to be in normal range. I appreciate the web site info for the owners manual. I purchased the Chlymer manual a couple of months ago and it is like reading Greek to me. Wish I had saved that money for Gas!!!

Re: Engine stall and cranking in a Mercruiser alpha 1 4.3l

Depending on the oil viscosity you are using, 80 PSI is high but not too high with cold oil on plane. When oil gets hot oil pressure will drop some. For GM engines 10 psi/1000 RPM is considered normal so 40 PSI or more at 4000 RPM is great. As long as you have SOME oil pressure at idle you are ok but its a sign your engine is beginning to age. If oil pressure is low at idle and it doesn't hold 30 - 35 PSI at cruise speeds you might start thinking about your options.

Re: Engine stall and cranking in a Mercruiser alpha 1 4.3l

You hit right on the head. The oil pressure is highest when I first run the boat, then drops after warming up into the 150-160 psi range. Never had a problem with low pressure at idle. The air temp has been in mid 70's and water temp in mid 60's. Do know if that makes any difference. Thank you.