cold start

[skicat]

I have a 2000 5.7 carb. mercruiser. It is a little hard to start cold. I set the choke, pump the throttle an additional time and give it a quarter throttle, but it takes a minute or two of cranking to fire. After it is warm, it starts right up and runs great every time. The engine has 160 hours. Is a tune-up in order? Where do I start? Thanks!

 

[Don S]

Re: cold start

A tuneup should be done on a boat every spring to get ready for the season.<br />If you have never done one (as it sounds) then you have lost a lot of power and fuel economy by running on the original plugs cap and rotor.<br />Tune it up ASAP.

 

[rbezdon]

Re: cold start

The other thing is with a carb engine, sometimes after sitting for a couple f days the fuel evaporates out of the carb. It takes about a minute of cranking to get the pump to refill the float bowl in the carb. I have the same situation. If the boat has been sitting a bit or trailered, then the very first crank takes a little while. I usually just crank it for about 15 seconds or so just to pump some fuel. Then pull out the control arm to neutral and pump the throttle a couple of times after the short crank. This speeds up the process a bit. You can verify my theory by pulling the spark arrester the next cold start after a couple days of sitting and have someone pump the throttle and see if any gas spits from the accelerator pump. Then crank the engine for 15 seconds or so and pump again. I bet little to no fuiel pumps the first time but much more pumps after the crank.<br /><br />No way I know of to stop this and if anyone else knows I would love to hear how so I can stop this too.

 

[skicat]

Re: cold start

Thanks Don s and Vatter41 The empty fuel bowl sounds right as I go boating every one or two weeks. I will try your starting procedure next time out. As far as the tune-up I suspect it has never been tuned up. What would you think about having it tuned up before they winterize it? The boat dealer is 35 miles in the other direction of the lake. Is a tune-up just plugs cap and rotor? I think I could handle that.

 

[rbezdon]

Re: cold start

add points to the list and ALL (in line fuel and seperator) filters. Timing, dwell adjustment, and carb adjustment and your just about there. Plug wires if they need it. Oil change wouldnt hurt either while you're dirty.

 

[skicat]

Re: cold start

I change the fuel filter every year. Does a 2000 5.7 still have points? The boat has been taken care of, and the engine compartment still looks like new.

 

[Don S]

Re: cold start

No points in Mercruiser since the early 80's. You have the Thunderbolt V ignition.<br />You should also verify the electric fuel pump is running when you first start cranking. If not, that may be part of your starting problem. The fuel pump works off the starter solenoid during cranking, and when the oil pressure builds up, power to the pump is through the switch while running. Now, if you have to crank long enough for the oil pressure to build up so the pump starts, then it could be hard to start.<br />#5 is the oil pressure switch and check the purple/yellow wire from the starter.<br /><br />

 

[Fishermark]

Re: cold start

I suspect the choke is not closing as it should. With the engine cold, before you try anything else, remove the flame arrestor and look at the top of the carb. The choke should be open. When you move the throttle forward, the choke should close - "setting the choke" as you mentioned. Carb linkages can and do get in a bind with gum, carbon, etc. Make sure the choke plate moves freely. Some carb cleaner sprayed on the choke shaft should free things up.

 

[skicat]

Re: cold start

Thanks again for the advice. I will check the choke, and fuel pump when I go out next week.

 

[skicat]

Re: cold start

Vatter41 you were right on with your advice. After sitting for a week the carb was dry. The choke works fine. I now crank the engine for 15 seconds, pump the throttle a couple times in neutral and it fires right up.

 

[milkyway]

Re: cold start

Does 15 seconds of engine cranking sound good? Sounds too long for me. I have the same ignition as yours, and mine ( after tips from the guys here) starts right after I turn the ignition switch, after 2 to 3 throttle pumps.

 

[skicat]

Re: cold start

I would think it depends on how long between starts. I only run my boat every two or three weeks. I was not getting a shot of gas on my throttle pumps. cranking the engine first remedied that.