Mercury Sport Jet 90 Owners

[SB]

I have a Sport Jet 90 on a Bayliner Reflexx. The boat is always hard to start and I finally determined that it was because there was no fuel being delivered. The Clymer shop manual says that the fuel pump isn't strong enough to draw fuel from the tank during cranking therefore a primer bulb is installed in the fuel delivery hose. <br /><br />Guess what, my boat doesn't have one. I also see that Mercury sells an auxillary electric pump for the Sport Jet (for $114).<br /><br />I am wondering if others have primer bulbs or is there a safety reason to not use them in an inboard engine.<br /><br />It would be easy enough to add a bulb and cutoff to the fuel line but would it be safe?<br /><br />Thanks,<br /><br />Scott

 

[kenimpzoom]

Re: Mercury Sport Jet 90 Owners

My 95 Sea Rayder has a Merc Sport jet 90 and I dont have a bulb.<br /><br />You may need to rebuild the fuel pump like I did. Its pretty simple.<br /><br />P.S. There are many other causes for hard starting. Stators are known probs with this engine.<br /><br />Ken

 

[SB]

Re: Mercury Sport Jet 90 Owners

What symptoms were you having that made you rebuild your fuel pump?<br /><br />Mine runs fine (or at least it did until last week when the trigger went bad, but that is another story) but is hard to start.<br /><br />When I first crank it with the choke on it fires fairly easily but dies in a couple of seconds no matter what I do. I then continue cranking with or without the choke and eventually it starts and runs fine from then on. It seems like fuel left in the carbs burns but there isn't enough new gas pumped in to continue running. It is worse if I don't use the boat for a couple of weeks.<br /><br />Scott

 

[ODDD1]

Re: Mercury Sport Jet 90 Owners

SB, primer bulbs are not used on inboard engine installations for a very good reason....the same reason that your fuel lines are twice as thick as the same fuel system on a outboard...they have to pass a two minute fire test without rupturing....the coast guard has these regs for a good reason, dont jepardize the safety and insureabilty of your boat for cheapin out an savin a hunnert bux....

 

[SB]

Re: Mercury Sport Jet 90 Owners

That what I thought also. It just puzzled me when the Clymer shop manual stated "Since this type of fuel pump cannot create sufficient suction to draw fuel from the tank during cranking, fuel is transferred to the carburetors by operating the primer bulb installed in the fuel delivery hose."<br /><br />I suspect that this was taken from the outboard manual for the same engine.<br /><br />Now, can I add a petcock so I can run the carburetors dry before taking the boat out of the water. This shouldn't affect the safety should it?<br /><br />Thanks.

 

[kenimpzoom]

Re: Mercury Sport Jet 90 Owners

I didnt have any symtoms, my boat had been sitting for 3 years and everything was gummed up as I didnt take care of it.<br /><br />I rebuilt the carbs and decided to rebuild the fuel pump while I was at it.<br /><br />My boat starts easily since then. When hot it starts within 1/2 second!<br /><br />Cold it takes a few seconds, crnak first, hit choke, let idle, as engine tries to die, hit choke for 1/2 second, continue as needed until warmed up for 30 seconds, then runs great.<br /><br />Before carb rebuild, it was a pain to start, and would harldy run in the end.<br /><br />Perhaps you need to do the same. It was really simple, carbs are very basic, and there is no tuning required.<br /><br />Ken

 

[SB]

Re: Mercury Sport Jet 90 Owners

That may not be a bad idea and not too expensive. Did you use a rebuild kit for the carbs and pump and where did you get them.<br /><br />Thanks,<br /><br />Scott

 

[clanton]

Re: Mercury Sport Jet 90 Owners

The OMC Turbojet has a primer inside the engine compartment.Look at 1995 115hp parts book.

 

[kenimpzoom]

Re: Mercury Sport Jet 90 Owners

I purchased gasket kits for carbs and fuel pump rebuild kit at a local parts place in Highlands, TX for a total of 20 bucks for everything.<br /><br />All the carb kits had was gaskets, no needle and seat or jets.<br /><br />Fuel pump kit had new diaphram and gaskets.<br /><br />I just used a ton of carb cleaner and let the carbs soak for a week in paint stripper that I had laying around. They were really gunked up.<br /><br />Ken