Some 1994 GTS questions

[Dougsnash]

Guys, I picked up a 'new to me' 1994 GTS last week which has been sitting since last season. I have been going through the machine trying to get it running reliably. While I think I have most of the gremlins out of the beast, I have a couple of questions I hope someone can shed some light on.

1. Where physically does the buzzer live? I have two empty plugs attached to the back of the 'dash' and I suspect one of them originally held the buzzer. I have tested the overtemp switch and there is no buzz so I suspect the buzzer was removed at some point.

2. How do I know which size needle and seat to order for the carb? The manual lists which jets to use in the SBN-38 carb for the GTS but does not list the needle and seat size. The retailer websites I have looked at generally list 4-5 different sizes when I search the 1994 GTS.

3. Is there an 'ignition switched' 12v source on the GTS? I plan on installing a OEM style tach and fuel gauge, and adding GPS/fish-finder on the machine and don't want to drain my battery when the machine is not in use. According to the wiring diagram in the manual, the gauges should be attached to the same circuit as the buzzer but it is not really clear whether that circuit is switched with ignition or not.

Some of the tasks I have dealt with are:

Replaced the grey fuel hoses with ethanol resistant automotive lines
Replaced the fuel sediment bowl screen and o-ring with new
Ordered a genuine Mikuni carb kit (cleaned up the carb with existing parts until kit arrives but don't plan on running beyond testing until rebuild is done)
Cleaned up the ground connections and some ugly wiring inside the grey electrical box (MPEM is from '92 and has relays instead of fuses). I had very intermittent spark until I cleaned up the coil ground.
Trimmed back 1/4" of the spark plug leads to get clean wire.
Installed new NGK BR7ES spark plugs gapped to .020 as per the manual.
Installed a new AGM battery
Wet sanded the upper gel coat and polished and waxed the machine.
Ordered a new seat cover
Fixed the return spring on the oil pump, pump was stuck at full flow

I am going to service the pump cone next. I have a Klotz service kit ready to go in.

Thanks to all of the experts who answer these forum questions, I have learned much reading other peoples questions and the many detailed answers.

Doug M

 

[GGuillot]

Guys, I picked up a 'new to me' 1994 GTS last week which has been sitting since last season. I have been going through the machine trying to get it running reliably. While I think I have most of the gremlins out of the beast, I have a couple of questions I hope someone can shed some light on.

1. Where physically does the buzzer live? I have two empty plugs attached to the back of the 'dash' and I suspect one of them originally held the buzzer. I have tested the overtemp switch and there is no buzz so I suspect the buzzer was removed at some point.

2. How do I know which size needle and seat to order for the carb? The manual lists which jets to use in the SBN-38 carb for the GTS but does not list the needle and seat size. The retailer websites I have looked at generally list 4-5 different sizes when I search the 1994 GTS.

3. Is there an 'ignition switched' 12v source on the GTS? I plan on installing a OEM style tach and fuel gauge, and adding GPS/fish-finder on the machine and don't want to drain my battery when the machine is not in use. According to the wiring diagram in the manual, the gauges should be attached to the same circuit as the buzzer but it is not really clear whether that circuit is switched with ignition or not.

Some of the tasks I have dealt with are:

Replaced the grey fuel hoses with ethanol resistant automotive lines
Replaced the fuel sediment bowl screen and o-ring with new
Ordered a genuine Mikuni carb kit (cleaned up the carb with existing parts until kit arrives but don't plan on running beyond testing until rebuild is done)
Cleaned up the ground connections and some ugly wiring inside the grey electrical box (MPEM is from '92 and has relays instead of fuses). I had very intermittent spark until I cleaned up the coil ground.
Trimmed back 1/4" of the spark plug leads to get clean wire.
Installed new NGK BR7ES spark plugs gapped to .020 as per the manual.
Installed a new AGM battery
Wet sanded the upper gel coat and polished and waxed the machine.
Ordered a new seat cover
Fixed the return spring on the oil pump, pump was stuck at full flow

I am going to service the pump cone next. I have a Klotz service kit ready to go in.

Thanks to all of the experts who answer these forum questions, I have learned much reading other peoples questions and the many detailed answers.

Doug M

You seem to be on the right track to making it reliable once you get out on the water, kudos to you. Look inside the steering cover for where the buzzer would live. Verify on the wiring schematic in the SM for color codes. On the later models like my 2 skis it's purple/tan and tan/black. There's various replacements out there for a buzzer, OSD marine and ebay are good sources. I've had good luck with a radio shack buzzer.

On the needle/seats, check Sea Doo PWC Carburetor Reference it lists 2.0.

You can cross check some of the other manuals if the 94' is incomplete or not clear SeaDoo Manuals - FREE PDF Download! a lot of the color codes were the same from year to year models. On my 2 skis a solid purple and black are the wires for 'power on' to the gauges. Break out a meter and check/test when in doubt. Buzzer is on it's own feed from the MPEM.

 

[Dougsnash]

On the needle/seats, check Sea Doo PWC Carburetor Reference it lists 2.0.

Thanks for that link, I have most definitely bookmarked it. I will get a new needle and seat on order and change them when I do the carb kit.

I will look at the steering cover tomorrow and see if the buzzer is still there. Who knows, it may just be unplugged. As for the accessories, I will chase those electrons when the parts arrive.

Thanks again

Doug

 

[wabash]

order your carb kits from OSD. You’ll get everything you need and not what you don’t. And it will be correct Mikuni parts and if you get the complete kit it will come with new needles and seats

 

[wabash]

Oh and just because you replaced the grey tubing I would still avoid running ethanol fuel. Nothing but trouble. Also I suggest only running premium fuel 91 or higher octane. Detonation will destroy these motors and you’ll never hear it. They are fairly high compression so it’s pretty easy to get detonation.

 

[GGuillot]

Oh and just because you replaced the grey tubing I would still avoid running ethanol fuel. Nothing but trouble. Also I suggest only running premium fuel 91 or higher octane. Detonation will destroy these motors and you’ll never hear it. They are fairly high compression so it’s pretty easy to get detonation.

Really? Not necessary on a stock engine, I run 87 ethanol based fuel with marine stabil added on both of my 787 skis. But...unlike others that like to close the HS needles on the carbs, I crack both open at 1/2 turn out. I might be trading 100 rpm or so on the top end, I usually see 6700 +- 50 rpm. At this setting I run can run them hard all day, constantly pegging WOT.

 

[Dougsnash]

I suggest only running premium fuel 91 or higher octane

I have many toys (too many I think) and I run 91 non-oxy in all of them. Almost all of my stuff will live quite happily on 87 fuel with up to 15 percent ethanol. I do not want ethanol in my homebuilt airplane, however, so all of my recreational fuel jugs only get ethanol free fuel put in them. Stocking only one type of fuel makes it easy to know I have the good stuff for the airplane. And because I usually keep three or four jugs of gas handy for the airplane, it is easy to grab one or two to fill one of the other toys.