[Gmecm] Rochester TBI on a Boat

Tue Jul 5 00:47:23 UTC 2005

 The 3.0 you have is an inline 4 engine related to the Tech-4 2.5, right?
That would be an easy conversion seeing how the Tech-4 engines were most all
TBI.  Definately go for it!
 Here in Alabama, our marine police mainly enforce safe boating and boat DUI
laws.  I have never been pulled over but my father has been.  They didn't
even open the engine cover- just asked him to show his fire extinguisher,
oar, horn and drivers license (yes you have to have a drivers license
endorsement to drive a boat in Alabama).
  If you are in an area where the coast guard is going to be patrolling,
they may be more stringent.  Especially on larger boats where there is an
actual engine compartment that could trap fuel vapors and explode.  From my
training,  what I have read,  and from talking to other marine mechanics,
the main things they look for are the backfire-arrestor air cleaner,
screw-down distributor cap (no spring-loaded clips), ignition-protected
starter and alternator, and the fuel system must have a double-diaphragm
fuel pump if it has a mechanical pump.  Bilge blower must work and be of
adequate size.
  They look for things that might indicate a damaged or leaking fuel system,
hoses rotten, clamps, anything that looks like it has been patched.  You are
far more likely to get written up for a completely stock but very neglected
system than you are for an EFI retrofit done properly.
  There are boat hull length classes that govern the degree to which a boat
will be scrutinized.  These little 18 or 19 foot ski boats and speed boats
are considered "toys" and they are not subject to much scrutiny.  Before I
converted a bigger boat I would want to read the fine print but I don't
think there would be a problem.  A friend has a yacht with 2 inboard
Mercruisers with Chevy 350's and Borg Warner Velvet-Drive gearboxes.  He
wants a pair of TBI's put on these engines.
  As far as my boat goes, the only electrical parts I added or changed that
could possibly be an ignition source are the distributor and the relays in
the ECM box.  The ECM box is air tight and couldn't ignite an explosive
atmosphere.  The distributor is the same design as what came out of the boat
from the factory, except for the electronic module instead of a points and
condenser setup.
  In working on bigger boats I can tell you a fact- you definately DO want
to keep the ignition-protected engine electrics.  We were out on the river
in a twin engine boat with a 3KW Onan generator.  The engines began running
rich so we stopped to check it out.  The reason they were running rich is
because the generator had leaked about 3 gallons of gas into the bilge, and
the vapors were so heavy it was affecting the engines' AFR.
  We had stopped and re-started the engines and generator twice during this
problem before we opened the engine hatch.  I'm still here to talk about
this so I can tell you- the ignition protected electronics DO work and are
extremely important on a boat.
  Under almost all circumstances a TBI is safer than a carb from a fire
standpoint. I've seen a quadrajet on an overheated engine boil fuel in the
bowl after shutdown and set off the highest warning on the gas fume
detector. This was without any real "malfunction" other than a mild
overheat.  Can't count the boats I have worked on where the carb would flood
out due to needle/float/ seat trouble and cover the engine in gas.  TBI is
definately the way to go!
  David

----- Original Message ----- 
From: "David Cooley" <n5xmt at bellsouth.net>
To: <gmecm at diy-efi.org>
Sent: Monday, July 04, 2005 2:47 PM
Subject: RE: [Gmecm] Rochester TBI on a Boat

> As far as marine grade, as long as the air cleaner is marine certified
> (Spark/flame arresting etc), the parts underneath are standard automotive.
> Though knowing california it probably also has to meet some smog
regulations
> now as well...
>
>
> > -----Original Message-----
> > From: gmecm-bounces at diy-efi.org
> > [mailto:gmecm-bounces at diy-efi.org] On Behalf Of Nicholas Hromyak
> > Sent: Monday, July 04, 2005 12:58 PM
> > To: gmecm at diy-efi.org
> > Subject: Re: [Gmecm] Rochester TBI on a Boat
> >
> > I had always thought about doing this on our Four Winns
> > (1987) too.  It has a 3.0 with a Cobra outboard, but I
> > thought the "marine police" would get me.
> > I understand everything must meet "marine grade" use - or
> > something to that effect here in California.
> >
> > Looks like fun.   Maybe I will do it too.
> >
> > Thanks for sharing.
> >
> > ----- Original Message -----
> > From: "David Allen" <davida1 at hiwaay.net>
> > To: <diy_efi at diy-efi.org>; "GM-ECM" <gmecm at diy-efi.org>
> > Sent: Sunday, July 03, 2005 10:48 PM
> > Subject: [Gmecm] Rochester TBI on a Boat
> >
> >
> > > You guys might find this interesting.  It runs great and is
> > much more
> > > reliable considering a boat sits up months at a time and no
> > carb to gum
> > > up.
> > > The linked page shows some pictures of the retrofit and it
> > may take a
> > > while
> > > to load with a dial-up.  I am not a savvy enough web page
> > designer to do
> > > thumbnail pictures.
> > > Later,
> > > David
> > >
> > > http://home.hiwaay.net/~davida1/boat.htm
> > >
> > > _______________________________________________
> > > Gmecm mailing list
> > > Gmecm at diy-efi.org
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> > >
> >
> >
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