Trouble restarting when hot and sitting more than 10 mins (4.3L engine) - Maxum Boat Owners Club

PCweber · 08-09-2010, 07:23 PM

I have a SC 2100 I got in June. It has the GM 4.3L engine. Runs great but does not like to start well when warm and boat has shut off for more than 10 mins. It is like the heat under the engine cover has an effect on things. I need to put lever in neutral and give it a tad bit of throttle above idle and it starts and needs revved a bit, then is fine. Any ideas?

seapuppy · 08-09-2010, 08:32 PM

first off..welcome to the zoo..2nd off...sounds like the heat is either boiling off the gas or your fuel line is vapor locking some....check the routing of the fuel line..make sure it's not sitting near or close the engine block....
also..before shutting off the engine..let it idle some...

SP

PCweber · 08-09-2010, 09:00 PM

I will try the idling idea before shiutting off. Can you expalin how that helps?

seapuppy · 08-09-2010, 09:30 PM

well..it allows the engine to cool down some..as well as the intake manifold and carb...since the carb relys on cooling water and air to keep it from boiling the fuel off....the cooling of the intake helps with that....also check to see if the carb is torqued down properly....it maybe causing a slight vacuum leak after the engine is warm and everything expands...which causes a lean condition ..which makes it harder to start...

SP

ed & inge · 08-09-2010, 09:50 PM

hai web,

maybe also an idea to keep the blower on for a few minutes after you shut the engine off......it will take the heat faster away from the engine compartiment.....

greatz,ed

PCweber · 08-10-2010, 01:39 AM

another good point. I will do this also.

Le Miss Tiffany · 08-11-2010, 04:21 PM

Hey thanks man ... this help me too, this is confirm what I try yesterday afer a few minutes of thinking ... I keep the motor runs a bit before I close it and it help when I restart it, but I didn't try to keep the blower on, I'll try it next time ... I had the exact same motor and it appends to me too!

PCweber · 08-13-2010, 11:14 AM

We went out last night. Still having same issue. My temp gauge never gets above around 160 when running. But if I leave it off for more than 15 mins I still have to crank for 30-45 seconds. I looked at the fuel line from the fuel pump to the carb and it is a steel line. No way it can be in an abnormal position from stock. Anyone ever add an electric fuel pump in line to switch on momentarily to get it started and have that help?

ss3964spd · 08-13-2010, 03:28 PM

PC,

A bit of troubleshooting for ya; next time you take the boat out bring a flash light, and tools to remove the flame arrestor. Run it up to opertating temp and, before you shut it down, open the cover and remove the flame arrestor. Shut it down (or remove it after shutdown, but be quick about it), then use the FL to look down into the carb. If you see any gas dripping inside the carb from the engine is flooding and causing the hard restart. If you see no gas dripping let the thing sit for 10 or 15 minutes and then check the position of the choke blade. After only 10 or 15 minutes it should still be completely open.

Dan

PCweber · 08-13-2010, 03:55 PM

great ideas. i will try that. I also will pump the throttle while watch before the restat to see if there is gas in bowl to squirt. (in case it is leaking out)

ss3964spd · 08-13-2010, 10:29 PM

Don't pump it until you wait for the 15 minutes. Ya need to try to replicate the normal circumstances under which the difficult re-start occurs.

If everything is working right, once at operating temp the engine shouldn't need the throttle moved at all in order to restart.

I didn't ask, but did assume that the engine is properly tuned; good plugs, cap, rotor, wires, timing.

Dan

cj · 08-17-2010, 10:53 PM

My Maxum 2400 scr and my Caravelle both do the same thing. They need about 5-10 sec of cranking to start, but it fires right up in the drive way when running on the hose, go figure. I Idle it prior to shutdown and it seems to help a bit, but I was told and believe it is just a product of having a carb job......mpi next time around!
Cheers