1998 502 Magnum MPI
10-03-2011 | 09:57 AM
#1
Thread Starter
Registered
Joined: Oct 2011
Posts: 2
Likes: 0
1998 502 Magnum MPI
Hey..I'm new to this site and was hoping someone would be able to help me out with a problem I'm having.
I just restored a 87 Scarab 3 inside and out but haven't really done anything to the engines (twin 502 Mag MPI Bravo Gen 6 1998).
I have been using the boat for about two months now and they have been running fine and fast but I'm having a problem now, once I go anywhere and sit for more than an hour they won't start back (just rolls and rolls). If I spray starter fluid in them they will kick off. The last time I went out one would not start at all. It seems to be getting fire and fuel and the only how I can get it started now is spraying LOTS of starter fluid and it then runs fine.
Can anyone give me some pointer on where I should start with this?
Thanks for any info you guys can give!!!
I just restored a 87 Scarab 3 inside and out but haven't really done anything to the engines (twin 502 Mag MPI Bravo Gen 6 1998).
I have been using the boat for about two months now and they have been running fine and fast but I'm having a problem now, once I go anywhere and sit for more than an hour they won't start back (just rolls and rolls). If I spray starter fluid in them they will kick off. The last time I went out one would not start at all. It seems to be getting fire and fuel and the only how I can get it started now is spraying LOTS of starter fluid and it then runs fine.
Can anyone give me some pointer on where I should start with this?
Thanks for any info you guys can give!!!
10-03-2011 | 10:12 AM
#2
Charter Member
Joined: Jan 2001
Posts: 7,663
Likes: 2
From: Edgerock Baby!!
These engines have had lots of problems with vapor lock. You could install an electric boost pump at the tank which will normally cure it by pushing fuel through the mechanical pump and up to the main electric pump. If you have VST tanks on your engine then you could remove them and plumb a high pressure electric pump at the tank and fuel pressure regulator that returns fuel to the tank, this will absolutely cure the issue.
10-03-2011 | 10:32 AM
#3
Registered
Joined: Oct 2005
Posts: 1,899
Likes: 20
From: Millstadt, IL
These engines have had lots of problems with vapor lock. You could install an electric boost pump at the tank which will normally cure it by pushing fuel through the mechanical pump and up to the main electric pump. If you have VST tanks on your engine then you could remove them and plumb a high pressure electric pump at the tank and fuel pressure regulator that returns fuel to the tank, this will absolutely cure the issue.
10-03-2011 | 12:00 PM
#4
Charter Member # 55
Joined: Oct 2000
Posts: 20,271
Likes: 2,512
From: Omaha/LOTO
Vapor Lock for sure. The solution is the Merc booster pump kits or run a return line back tot he tank instead of back to the water sep filter.
E10 fuel will also cause them to vapor lock much easier. Opening your hatch and running the blowers after you dock will also help.
E10 fuel will also cause them to vapor lock much easier. Opening your hatch and running the blowers after you dock will also help.
10-04-2011 | 06:00 PM
#10
Banned
Joined: Feb 2004
Posts: 397
Likes: 0
From: South Florida
Hey..I'm new to this site and was hoping someone would be able to help me out with a problem I'm having.
I just restored a 87 Scarab 3 inside and out but haven't really done anything to the engines (twin 502 Mag MPI Bravo Gen 6 1998).
I have been using the boat for about two months now and they have been running fine and fast but I'm having a problem now, once I go anywhere and sit for more than an hour they won't start back (just rolls and rolls). If I spray starter fluid in them they will kick off. The last time I went out one would not start at all. It seems to be getting fire and fuel and the only how I can get it started now is spraying LOTS of starter fluid and it then runs fine.
Can anyone give me some pointer on where I should start with this?
Thanks for any info you guys can give!!!
I just restored a 87 Scarab 3 inside and out but haven't really done anything to the engines (twin 502 Mag MPI Bravo Gen 6 1998).
I have been using the boat for about two months now and they have been running fine and fast but I'm having a problem now, once I go anywhere and sit for more than an hour they won't start back (just rolls and rolls). If I spray starter fluid in them they will kick off. The last time I went out one would not start at all. It seems to be getting fire and fuel and the only how I can get it started now is spraying LOTS of starter fluid and it then runs fine.
Can anyone give me some pointer on where I should start with this?
Thanks for any info you guys can give!!!
