1990 Mercruiser 4.3 Alpha 1 - Starts Hard

[Flintindians]

I have a 1990 Mercruiser 4.3 Alpha1 and I have been having issues which I believe are related to the fuel system, but not sure. The current issue is when Iam driving full-out and slow to idle the boat stall and then its a bear to restart. (Maybe Flooding) The boat also starts very hard everytime. I have to give full choke when starting and then is takes a few minutes. I have replaced the Fuel Pump, Fuel Lines, Anti-Siphon valve, I had a shop work a tune-up on it. It seems to me when it stalls that the carb is giving an excessive amount of fuel, i do not no what is normal. If anyone has had this problem or has any ideals what to try next I would greatly appreciate it. The carb is a double barrel, and the boat runs great when not at idle or starting.

 

[rattana]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

Can you smell fuel, that would be a sign that it is flooded. Has anyone worked on the carb? What color are your sparkplugs?

 

[Flintindians]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

You can smell fuel, I will check the spark plugs.

 

[Flintindians]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

The sparkplugs look good! I have been told that the mercury carbs sometimes need adjustments the float and needle valve? It will sometimes leak after shut down. Does this make any sence?

 

[vipzach]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

I think I would get the carb rebuilt. You don't want any extra gas in that engine compartment!

 

[Flintindians]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

I took all the covers off and dropped into idle. There was gas dumping into the carb, litterally filling up. I think I will take it in to have the carb re-built.

 

[hoot]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

make sure the mechanic checks/replaces float and the level and drop measurements for the float.

 

[vipzach]

Re: 1990 Mercruiser 4.3 Alpha 1 - Starts Hard

You might check your oil when you get it back, make sure it doesn't smell like gas.