Hard to start when warm

[pensacola]

For some reason my boat starts instantly when its cold. But when its warm it takes two to three times to start every time. Then if we are hanging out for a while and it cools down it starts instantly. I have a 99' Mercruiser 305 5.0 2-barrel.

 

[Haut Medoc]

Re: Hard to start when warm

Probably needs a choke adjustment......​

 

[pensacola]

Re: Hard to start when warm

Thats the direction I was going towards. I already had the carb rebuilt and replaced the fuel pump. It runs great, just have to crank it twice. I can bump it the first time, then it starts the second or third time.

 

[Haut Medoc]

Re: Hard to start when warm

Pull the flame arrestor off & note the position of the choke plate....
Are you pumping it before the warm starts?....​

 

[pensacola]

Re: Hard to start when warm

When I was having other problems I looked at the choke and it was right. But I have not checked that since its been running right. I did try pumping it before starting and it didn't seem to help.

But I haven't tried the full throttle thing like I have seen in other posts in case it is flooding. It shouldn't be since I just had the carb rebuilt.

 

[Haut Medoc]

Re: Hard to start when warm

When I was having other problems I looked at the choke and it was right. But I have not checked that since its been running right. I did try pumping it before starting and it didn't seem to help.

But I haven't tried the full throttle thing like I have seen in other posts in case it is flooding. It shouldn't be since I just had the carb rebuilt.

I was gonna say you should not need to pump it.....
I'd still look at the choke.....

 

[Reel Poor]

Re: Hard to start when warm

If a pump of the throttle didn't help it may be loading up on fuel. After you make your run and shut it down remove the flame arrestor and see if there is any steam rising from the carb throats or if you can see any fuel leaking into the venturies. If either one of these exist you may have a float level problem. Also if this is the problem some throttle advance (full throttle) on start up would probably help.

 

[pensacola]

Re: Hard to start when warm

Thanks for the advice. I will definetely try the full throttle thing and see if that works.

 

[PeteHarris]

Re: Hard to start when warm

I had a very similar problem on a 5.7 that turned out to be a bad coil in the ignition system.

 

[Haut Medoc]

Re: Hard to start when warm

I had a very similar problem on a 5.7 that turned out to be a bad coil in the ignition system.

Not the same thing.....
Though it does sound similar.......
What he is saying is that it runs fine once it restarts......
With a bad coil the engine would quit or misfire when hot......

 

[JustJason]

Re: Hard to start when warm

well... you are in florida, i know its not summertime yet but your engine box may be getting on the hot side. It may be something as simple as vapor lock. Try leaving your engine box cover popped and then run around the lake, see if that helps.

 

[bruceb58]

Re: Hard to start when warm

Before and after you stop next time, run your blower to get some of the heat out of the engine compartment and see if that helps.

 

[pensacola]

Re: Hard to start when warm

Not the same thing.....
Though it does sound similar.......
What he is saying is that it runs fine once it restarts......
With a bad coil the engine would quit or misfire when hot......

I actually just replaced the coil last weekend. We were going camping, had all the camping gear loaded up, started it at the house and it ran fine, got to the dock and it wouldn't start. Brought it home and replaced the coil, fired right up. So I know that ain't the problem. I hope it ain't vapor lock cause it wasn't even hot out when it happened and the temp. gauge was at normal temperature.