Seadoo speedster jet boat

[Water sports]

Hi

can some one help me I have a Seadoo speedster 787 2 stroke twin engines jet boat and I are wanting to find a oil sensors

 

[mikidymac]

The only sensor would be in the oil tank. Typically they are just a float that triggers an idiot light on the skis so I assume the boats are the same.

They only indicate low injector oil in the tank.

 

[Water sports]

Thank you so much for your quick reply this is well appreciated my concerns as the boat sounded a continuous alarm when I put it in the water and no will light was on I don’t have a temperature gauge in the boat either so I am trying to eliminate what this could be can anybody help me with this to try and pinpoint problems one issue I know the boat he’s is the fuel gauge is not working could this be the problem otherwise the boat ran like a dream in the water, but the boat did stop and was unable to start I took it home and flushed out both engines but the alarm sounding again

 

[mikidymac]

The alarm can also be overheating alarm.

 

[lithium2g]

Also goes off the fuel tank gauge shows empty even if you have a full tank

 

[Water sports]

The alarm can also be overheating alarm.

Are you saying the alarm is shorting out for faulty

 

[lithium2g]

Are you saying the alarm is shorting out for faulty

No. When one or both of the engines goes above 100 degrees celcius,. the temperature monitoring system will tell the computer it is overheating and it will notiofy the user by constantly beeping the alarm on the dash board.

This is useful to know if you are out on the water and something clogs your water cooling system and prevents the engine from cooling properly.

Of course there are other reasons the seadoo beep/alarm system will go off and a variety of beep patterns might indicate other problems that are described in the seadoo manual.

But a regularly interval beep will mean overheating

 

[Water sports]

But the strange thing is I just put the boat in the water the start of the engines and the alarm sounded they weren’t even hot, The boat drove very well but the alarm sounded Continuously but then we couldn’t get the boat to start again which was not good we were stuck in the water it felt to me it was like a petrol problem, my fuel gauge is not working at all its saying empty I had half a tank of gas

 

[lithium2g]

my fuel gauge is not working at all its saying empty I had half a tank of gas

Also goes off the fuel tank gauge shows empty even if you have a full tank

Like I said the same alarm will sound if the fuel gauge is not working. Mine does the same thing... i simply unplugged the alarm system from behind the dash board and i just check the engines every now and again when im out on the water.

The problem you have with your speedster not "starting" is likely unrelated to overheating/alarm sound.

I am not the person to ask for diagnostics with these boats, someone else might be able to go through the basic chain of troubleshooting though.

If you haven't yet (sounds like you haven't), sign up for membership and download the manual for your particular model. Its linked up the top of the website page

 

[Water sports]

Ok thanks for your reply, I really appreciate it,

 

[Water sports]

Hi I am wondering if someone could help me diagnose a problem I have
I own a Seadoo speedster jet boat twin engine 787 two stroke,

problems I am experiencing,

-putting the key In place and only getting to faint sound, then other times it is too loud chips/beeps Key relatively new.

-Replacing all carb gaskets etc in carbs do I need to use a Gauge to pop off them.

-also what is the best option to service both engines in the boat what do you recommend I carry out.

 

[mikidymac]

It sounds like your beeper is going out which is pretty common but is necessary so you know it is recognizing the lanyard. The beeper is also your overheating alarm and on some boats the low fuel alarm too. These are a simple contact switch so check your tank float and see if it is functioning. Basically switch closed = alarm on.

For carbs you should do a full rebuild with Genuine Mikuni parts including needle and seats. OSD Seadoo has a one stop shopping with everything you need and yes, you should check pop-off and leak down along with new fuel filters.

You should also make sure you are only running full synthetic API-TC oil, change the small 3/32" oil injection lines when the carbs are off and replace the in-line oil filter. Clean the RAVE valves, check the rubber diaphragm on the muffler water regulator. Change the jet pump oil and inspect the driveshaft carbon seals.

 

[Water sports]

Hi I am just reconditioning my carburettors for a seadoo speedster twin engine 2 Stoke jet boat and have come across the jets have been stripped on a couple of the tops where a flat screwdriver fits and hard to get out however I have managed to get these out without damaging anything, I am wanting to replace the jets, how do I match the size of the jets

 

[Water sports]

Can you help me with my
carburettor it is pulled down and I am wanting to replace my carburettor jets and I’m finding it hard to get the number of them on the sides On one of the bigger ones I have seen 145. how do you think I can go ahead with this are these standard for carburettor jet and are they the same for both back and front cab

 

[mikidymac]

What year is your boat and model?

 

[Water sports]

1999 seadoo speedster 787 twin engine 2 stroke

 

[mikidymac]

145 mains
67.5 pilots
1.5 needle and seats.

Places like OSD Seadoo and Westside Powersports Seadoo can hook you up with everything you need to do it correctly.

 

[Water sports]

Great thank you so much that is a huge help can you just verify that the mains are the same on all four carbs

 

[mikidymac]

Good call.
It shows 145 main on PTO carb (rear)
142.5 on the MAG (front)

Only shows 1 pilot.

 

[Water sports]

Okay each carb has got a big jet and a little jet So just trying to determine what the little jet number is

 

[Water sports]

so do you think the pilots are 67.5

 

[mikidymac]

The physically smaller jet is the pilot jet. The larger jet with the big head is the main jet.

Each carb only has 2 jets total.

All pilots should be 67.5 and are stamped on the side.

 

[Water sports]

The small jet is saying 67.5 would it matter if I put in a 70 ithis is all I can get on site

 

[Water sports]

Hi I am currently working on my jet boat and have a couple of questions,

-If I remove top section of the motor, where the water comes out, with this loosen the head and well I need a new gasket, I just want to remove it to see if there’s any buildup of salts.

-I am reconditioning my carburettors and want to make sure that I do put the right ones back in, can someone just double confirm the numbers of both jets.

-I am just looking at the petrol tank piping and there is a round black plastic thing what is this it is not the petrol filter.

 

[mikidymac]

1. Yes you will need new o-rings.

2. I have already confirmed them for you. Do not use a 70 when it calls for a 67.5.

3. No, that is just the pickup, the filter is seperate.