3.0 Mercruiser Warm Start Issues

[Dodgethis85]

New member here....

Just picked up a 2007 sea ray 175 sport. Boat cold starts and runs great but sometimes struggles to warm start. I always run engine ventilation fans but sometime boat will not crank when warm at it requires me to pop engine hood and crank while feathering throttle. I have read somewhere that vapor lock could be an issue but I am not sure where to start. Boat runs at wide open throttle no issue and idles fine but will not warm start every time. I have replace fuel filter and water separator filter.

Any advice/ideas?

 

[Jim Juritsch]

I had similar issues with my 3.0. Mine didn't have any insulation on the metal fuel line, which runs across the top of the engine. I added insulation to the fuel line. Go to Summit Racing and search on item# 274012. You can wrap it on the fuel line without removing it. (velco). Solved my warm start problem.

 

[Dodgethis85]

I had similar issues with my 3.0. Mine didn't have any insulation on the metal fuel line, which runs across the top of the engine. I added insulation to the fuel line. Go to Summit Racing and search on item# 274012. You can wrap it on the fuel line without removing it. (velco). Solved my warm start problem.

Thanks. I already ordered that to rule out vapor lock and heat soak. Hopefully this will cure it.

 

[Bt Doctur]

is this a TKS carb?

 

[Dodgethis85]

is this a TKS carb?

Yes

 

[ZZ13]

I had the TKS carb on my 2009 175 Sport and had similar situation. There is a warm start procedure in the manual, if I remember. I believe I just had to advance the throttle in neutral to start it right up, then back it back down to idle once it starts. But double check the manual.

 

[Dodgethis85]

I had the TKS carb on my 2009 175 Sport and had similar situation. There is a warm start procedure in the manual, if I remember. I believe I just had to advance the throttle in neutral to start it right up, then back it back down to idle once it starts. But double check the manual.

I have read the same, I just don’t understand why you have to adjust the throttle for a warm start. Sometimes I have to give it almost full throttle.

 

[BillK2632]

Carburetors had a tendency to "perk" sitting on top of a hot engine after it is shutdown. This creates a flooded condition when you try to restart the engine. Opening the throttle clears that flooded condition and lets it start back up. Does not really have anything to do with TKS, happens on any carbureted engine. Mine (without TKS) does this, I will get a little fuel rich smoke from the exhaust on a hot start sometimes, but rarely have to open the throttle. One thing to check is that the throttle cable is adjusted so it is completely closing the throttle plate when it is in neutral. This will also cause run-on when you shut down and allow fuel to drip into the intake - hence the flooding when you go to restart.

 

[Dodgethis85]

Carburetors had a tendency to "perk" sitting on top of a hot engine after it is shutdown. This creates a flooded condition when you try to restart the engine. Opening the throttle clears that flooded condition and lets it start back up. Does not really have anything to do with TKS, happens on any carbureted engine. Mine (without TKS) does this, I will get a little fuel rich smoke from the exhaust on a hot start sometimes, but rarely have to open the throttle. One thing to check is that the throttle cable is adjusted so it is completely closing the throttle plate when it is in neutral. This will also cause run-on when you shut down and allow fuel to drip into the intake - hence the flooding when you go to restart.

Thanks for the feedback, I will check this.

 

[JVM225]

We have an 2005 18’ Maxum with a 3.0 in it that the kids use and it had the same problem. I had the carb off last year when I put a new exhaust on it. While it was off I gave it to a local rebuilder to rebuild. No more problems.

 

[Dodgethis85]

I’m thinking about doing the same, thinking the float may be messed up.