Mercruiser 470 hard hot start.

[Mark6299]

My engine starts fine cold. It cranks over very well. It barely cranks when hot. If I let it cool down past say 150 degrees, it cranks again. The starter is newly rebuilt be a reputable marine dealer. A couple years ago it started fine cold or hot, so I am thinking that it is the connections. I only used it a couple times these past few years. However, I am wondering what the engine would be harder to crank when hot. That doesn?t make any sense to me at all. Any thoughts?

 

[stonyloam]

Re: Mercruiser 470 hard hot start.

Always check the simplest explanation first, and you are thinking in the right (especially if the boat has been sitting) direction. Clean and tighten all of your connections, especially battery, starter and ground connections. See if that helps and work from there.

 

[snoski]

Re: Mercruiser 470 hard hot start.

Does it seem like it is trying to start (fuel problem) or does it seem like there is no fire to the plugs (electrical). If electrical, then after checking all the connections, I would check the coil....

 

[dennison17]

Re: Mercruiser 470 hard hot start.

I had a Merc 470 for years and had the same problem. Really puckers you up if you shut the engine off a lot (like if pulling skiers, etc) in the middle of the lake. I never did find out what the probelm was and I tried ALL of the above suggestions in this thread. All I can say is that it ALWAYS did start... but it sure gets your heart a thumping when it does that slllooowwww crank when very warm.

On a completely different note, I DID install an electronic ignition and that was the best money I ever spent on that boat. Eliminated all that points / condensor hassel.....

 

[Mark6299]

Re: Mercruiser 470 hard hot start.

I did change the points to electronic a while back too. I haven't had a chance to mess with it lately, but I will be taking her out this weekend for some skiing and tubing fun. I will clean up all the connections. It cranks really slow. It will do this till it cools way down, then fires right up. It kinda really sucks though to have to wait a half hour or so though.