Supercharged starting hard
 

Hi my friends. I have a Baja 1997 727 2 with a 454 supercharged weiand with single 4 barrel carb. The engine was rebuilt 20 hours ago by a very reputable mechanic .I know very little about the supercharger. I pump it about eight times to start. When it starts I have to play with it to keep it running until about 150° temperature. I feel the idle may be a little low at 500 RPM. Runs fine afterwards but when coming to the dock at idle it dies. I live in Clearwater Florida and would like to find a reputable mechanic that knows about these engines and superchargers. Anyone have any ideas of what could possibly be wrong which is a loaded question I know. Does anyone have someone in this area of St. Petersburg that knows about these engines which superchargers. Thank you for putting up with my ignorance.Boat just came from Idaho

it sounds like you have a tune up/timing or carburetor issue, either is easy to fix. I unfortunately don't know of any mechanics down there.

Is it a mercury 525 Sc with the 1050 Dom or is everything aftermarket install. If so what carb is on it. Could be a simple air screw adjustment down to a carb rebuild. I’d definitely bump the idle for starters along with checking/adjusting your 4 corner air screws.

Something you can easily do yourself. Keep track of each idle circuit screw by turning them all in one at a time and then turn back out 1 1/2 turns. Just write down what you do but sounds like your starving for fuel when cold.

You can fine tune one at time for best idle. Possible vacuum leak otherwise. Just a guess but I’d start with the basics. Hope that helps before you have to take boat to a mechanic.

Just another easy self check is your float bowl levels in addition to the above. Best to do while running however with your issues might be difficult so just check after running and engine cooled down just remove the front and rear screws and rock the boat a little and if you see a little fuel seep out then that's likely not your problem. Not sure if you have the plastic see though sight plugs or not. If so you should be able to see fuel without removal.

Thanks guys so much for your advice. Seems like I have a starting place. Because it’s a supercharged engine I figured it was going to be more difficult than that but we will see I hope

What do you think the Idol should be around? Right now it’s around five to almost 6

750-800rpm

500 rpm is way to low of an idle. And you shouldnt be having to pump a punch of times.... I do about a half a pump, open the throttle to just above idle, turn the key and its lit. 177 blower, dominator and timing locked out at 32 degrees.... Let it run for a minute or two at 1100 then it purrs at 750 with no problem going in and out of gear.

Thank you my friends for much help. Have a mechanic that’s going to look at it tomorrow and he knows a lot about them so we’ll see. Again thank you

At 500rpms, I'm not surprised it stalls. Bump the idle up to 750-800rpms in neutral