1980 Mercruiser 140

[Ratboy14]

Hi,

I have a 1980 mercruiser 140 on a 1980 19 foot starcraft and when I start the motor it needs alot of pumping on the throttle to get it to start and does not idle even after running for 5 minutes. When I give it full throttle I only get about 2000 rpms and the WOT for the engine is 4400-4800 or something like that. I have adjusted the points so many times but it didnt change. Could it be the timing or another problem? Also when Im in the water and give it gas not in gear it gets better idle. Could it be a drive problem with that?

 

[rbh]

Re: 1980 Mercruiser 140

sort of sounds like fuel and fuel delivery problem.How old is the fuel? you may have to pump it out if it is gotten to old. replace filters, try it, if no improvement then it may be a carb issue?
rob

 

[Hansolo99]

Re: 1980 Mercruiser 140

It sounds like the carburator. Did it sit for a while?? Sounds like you need a rebuild.

 

[thannah84]

Re: 1980 Mercruiser 140

I agree....Sounds like time to give the carb a good soak and get a rebuild kit for it....Fairly simple to do...Should be a Rodchester 2 Jet on that I think...Just for a piece of mind, I would check Dist Cap, Rotor and plugs/gap to make sure that you are getting adequite spark.....

 

[Ratboy14]

Re: 1980 Mercruiser 140

We just got the boat from a guy who had it in his yard sitting for around 5 years. There was no spark and we got new points, rotor, condenser and coil and got a spark. There was no fuel in the tank or carb. We shot starting fluid in the carb and it started right up so I dont think the jets are clogged. Dist. cap is in fairly good condition inside, no cracks but is dirty on the outside. The filter inside the carb is in unknown condition and we cant get the fuel line off on it.

 

[rbh]

Re: 1980 Mercruiser 140

even though there was no fuel in the tank there could be crud, when you put the new fuel in a the boat and moved it around it could be shaken loose. carry a spare filter to be on safe side.
rob

 

[thannah84]

Re: 1980 Mercruiser 140

I would go down to your local marine store and ask them for some good Additive for Carb. My mechanic gave me some Johnson/Evinrude/OMC Fuel Stabilizer and Carb Cleaner and It works Great. I would also do a compression test and check the timing. Timing could be way off causing it to start hard and run rough and also not reach it's RPM Range. Have you pulled the plugs to see what they look like after running? Also, I have a 2.5L GM in mine and if I Pump the throttle to much she floods and doesn't start easy. I give her about 1/4 Throttle and turn her over and she fires right up. Any more than that and she just spits until I back the throttle off.....

 

[Ratboy14]

Re: 1980 Mercruiser 140

I am going down to the boat later today. Ill try and take pictures and maybe a video.

 

[fishrdan]

Re: 1980 Mercruiser 140

There was no spark and we got new points, rotor, condenser and coil and got a spark.

You need to do a complete tune-up, change the cap, plugs and ignition wires also. The thing has been sitting for 5 years and who knows how old those parts are.

You mentioned changing the points, did you set the dwell also. If not, get a dwell meter and set the dwell, then set the timing. Using a feeler gauge or match book cover will get up in the ball park, but you need to adjust the dwell,,, this fine tunes the point gap adjustment. After the dwell is set, adjust the timing as it could have changed. To do the tune-up properly you will need; dwell meter, timing light, feeler gauges,,, and other hand tools. Dwell meter I bought from AutoZone was $30,,, and it also has a shop tach feature, nice for setting idle speed. (idle speed needs to be set with the boat in the water, engine warmed up and idling in gear)

It's normal to have to pump the throttle a few times before starting a cold carbed engine, this gives the engine a rich mixture to start it and also closes the choke. After the engine starts, do you press the shifter's nuetral button and then bump the engine rpm's to about 1000RPM to warm it up? Should take a few minutes at high idle to get the engine warmed up, after that it should idle fine.

If it still runs crappy once the ignition is tuned-up and adjusted, then you need to look into the fuel system. More than likely you have some work to do in the carb and fuel system. BUT, don't do that until the ignition system is completely tuned-up.

 

[Showtime22]

Re: 1980 Mercruiser 140

Sitting around for 5 years a carb can rust really bad from water moisture alone. Even if it was run dry of gas. I received my boats motor in a similar case and when I took apart the carb it was so rusty it was unfixable. Had to get a new carb.

 

[Ratboy14]

Re: 1980 Mercruiser 140

Me and my dad were on the boat today working on it and we got it running good when its not in gear but as soon as we put it in gear it just gets real shaky and running really rough. Could it be a drive problem? We dont know if there is gear lube in the drive so what would happen if there is none?

 

[rbh]

Re: 1980 Mercruiser 140

the leg go bang, boom or crunch, what does seizing gears sound like?
rob

 

[dubs283]

Re: 1980 Mercruiser 140

uh, yeah, need to check the drive for lube, one of the first things to do. check the level by removing top plug, port side of drive, and if nothing comes out, stick a wire tie or other small object to see if the level is low. then drain the old lube and replace it with quicksilver high performance gear lube. check old lube for metal flakes and the like

fishrdan offers sage advice, FULL, COMPLETE tune-up, then look into other areas for problems if this does not resove problem. tune-up is the easiest and cheapest repair for runabilty issues, and needs to be done every two years max!!

 

[jack gardner]

Re: 1980 Mercruiser 140

hello u stated u could not get the fuel line off . there is a filter in there that has to b changed. takes two wrenches to do it a 1 inand either a 1/2 9/16 or5/8 tubing wrench or better a tubing crows foot to remove.with rtchett . most of ur problem should b right there.then set dwell and timing and it should b good to go that filter is hard to remove sometimes due to over tightning of the fitting. but have seen it stop an engne when plugged

 

[Ratboy14]

Re: 1980 Mercruiser 140

hello u stated u could not get the fuel line off . there is a filter in there that has to b changed. takes two wrenches to do it a 1 inand either a 1/2 9/16 or5/8 tubing wrench or better a tubing crows foot to remove.with rtchett . most of ur problem should b right there.then set dwell and timing and it should b good to go that filter is hard to remove sometimes due to over tightning of the fitting. but have seen it stop an engne when plugged

I fixed the engine running problem partly. When its not in gear it runs really nice but as soon as you put it in gear (forward or reverse) it runs horrible. I think its something with the drive. Today were gonna work on the drive (change lube and seals). Does anyone have any idea why it runs good when not in gear to when it is in gear? I dont think its the engine out of time or something because when I take the wire off coil and crank the engine in gear it seems really hard to turn, I dont know if its because of the spinning of all the gears. (All is done out of water by the way).

 

[Showtime22]

Re: 1980 Mercruiser 140

I think its still the the carb.

 

[fishrdan]

Re: 1980 Mercruiser 140

You need to do a complete tune-up, change the cap, plugs and ignition wires also.


get a dwell meter and set the dwell, then set the timing.

Done this yet...?

 

[jacktc99]

Re: 1980 Mercruiser 140

I had the same issue and hopefully this may help. I bought a boat that had been sitting for years in a garage. The guy left gas in it and over time it had turned into varnish. I thought by removing it with a pump and putting new fuel in it would cure it. I can't tell you how long and how much money it spent figuring my fuel problem out but it was a nightmare. Rebuilt carb, new fuel pump, gas treatments, changing filters, adding a inline water separater, adjusting the carb for hours. Eventually, I got pissed and ripped up the floor only to find the gas hoses had rotted and my fuel tank was sitting in a pool of gas and water. I replaced the hoses and treated the tank. When I put it all back together I had no problem. These engines are also sensitive to higher octane gases. I found when putting 89 or 91 octane in it it would idle very different. Stick with 87 octane.