1995 Seadoo Gtx Fuel System Questions

[1986toyotapickup]

Lost interest in fixing up my 1995 GTX last year, but now I'm back at it with better mechanical skills and knowledge. Here's the questions I have regarding the fuel system. To convert to premix, I need to buy a block off plate, remove nylon gear, keep the oil lines to the crankcase, correct? Replacing all grey fuel lines is a must, what size hose do I need? What carb kits do I need? 657x. Anything I missed? Thank you guys!

 

[mikidymac]

No reason to go premix. Keep the oil injection. The only maintenance the oil system needs is ATP-TC oil, an inline oil filter and new 3/32" Tygon lines from the pump to the intake manifold. It will be cheaper than all the extra oil you will use going premix.

Easiest place for Genuine carb and oil injection parts is OSD seadoo.

 

[1986toyotapickup]

Problem is, previous owner tried to convert it to premix by removing the oil injection cable. How hard is it to replace and calibrate, or am i better just going to premix.

No reason to go premix. Keep the oil injection. The only maintenance the oil system needs is ATP-TC oil, an inline oil filter and new 3/32" Tygon lines from the pump to the intake manifold. It will be cheaper than all the extra oil you will use going premix.

Easiest place for Genuine carb and oil injection parts is OSD seadoo.

 

[mikidymac]

If you can get the cable it is easy. You just line up the marks on the pump arm and body with the nut on the cable.

 

[1986toyotapickup]

If you can get the cable it is easy. You just line up the marks on the pump arm and body with the nut on the cable.

Alright, I went to attempt and start it with gas down the carbs, good spark, nothing. It ran for 1 second, then never fired back up after that. Is this turning into too much of a problem for a beginner?

 

[burtshaver2021]

Definitely not to much for a beginner, most likely a carb rebuild with genuine mikuni kit from OSD marine following mikidymacs carb rebuild thread will have you on the water

 

[1986toyotapickup]

Definitely not to much for a beginner, most likely a carb rebuild with genuine mikuni kit from OSD marine following mikidymacs carb rebuild thread will have you on the water

So what your saying is, even though I'm pouring fuel down the carb, and its not starting, its a carb issue? Healthy spark and battery.

 

[mikidymac]

Test the compression. Do not use a Harbor Freight tester.
Use a thread in tester with a schrader valve in the sparkplug side of the hose.
Good battery, sparkplug cables grounded on the orange lugs, Fuel off, throttle wide open and crank until the needle stops climbing.
150 psi is perfect and at 120 it is shot.

 

[burtshaver2021]

So what your saying is, even though I'm pouring fuel down the carb, and its not starting, its a carb issue? Healthy spark and battery.

Sorry, I thought you had said with gas down the plug holes it ran for a second. If it’s not starting with mixed fuel poured in, then I would look elsewhere first. Compression, spark are good?

 

[1986toyotapickup]

Sorry, I thought you had said with gas down the plug holes it ran for a second. If it’s not starting with mixed fuel poured in, then I would look elsewhere first. Compression, spark are good?

Spark good, sadly, my compression is at 90 Will be saving up for a SBT core, and in the meantime, restore the rest of the ski.

 

[burtshaver2021]

Spark good, sadly, my compression is at 90 Will be saving up for a SBT core, and in the meantime, restore the rest of the ski.

You’re not using a tester from harbour freight are you? I believe they are made by Pittsburgh, they are notorious for reading 99 pounds maximum

 

[burtshaver2021]

Notorious for reading 90 pounds max. Not 99 as in my last post

 

[mikidymac]

Spark good, sadly, my compression is at 90 Will be saving up for a SBT core, and in the meantime, restore the rest of the ski.

You can and should do better than SBT.

 

[1986toyotapickup]

Notorious for reading 90 pounds max. Not 99 as in my last post

You can and should do better than SBT.

Alright, here’s what happened, I borrowed a Snap On compression gauge from a friend. Mag cylinder 130 pto 128. Thought to myself that it should run, did some more research, found a thread that talked about the engine being flooded with oil after sitting. Pulled the plugs, let all the oil squirt out, and she fires up! Will be doing gas lines and carbs now that I know it runs. Here’s everything else I found out, Im restricted to premix due to the previous owner JB welding the oil inlets on the rotary cover and the pump. Wear ring is in great shape! Hopefully with a carb kit I’ll be out on the lake.

 

[burtshaver2021]

Alright, here’s what happened, I borrowed a Snap On compression gauge from a friend. Mag cylinder 130 pto 128. Thought to myself that it should run, did some more research, found a thread that talked about the engine being flooded with oil after sitting. Pulled the plugs, let all the oil squirt out, and she fires up! Will be doing gas lines and carbs now that I know it runs. Here’s everything else I found out, Im restricted to premix due to the previous owner JB welding the oil inlets on the rotary cover and the pump. Wear ring is in great shape! Hopefully with a carb kit I’ll be out on the lake.

Well that’s good news, must not have been to much oil in there since it rolled over for you to check spark. Just out of curiosity did you check compression before you took the plugs out to get the oil out? I would be interested to see what compression is after it has ran on the water for a ride. I always crank my machines over in the spring with the spark plugs out and plug wires grounded just in case. It’s a good habit

 

[burtshaver2021]

If you end up rebuilding the carbs make sure they are genuine mikuni kits, I always buy mine at OSD Marine, the back to OEM kits. And re use your old spring, I’m pretty sure the spring on the 657x is impossible to get now, but either way, just make sure not to throw out the old spring

 

[1986toyotapickup]

Well that’s good news, must not have been to much oil in there since it rolled over for you to check spark. Just out of curiosity did you check compression before you took the plugs out to get the oil out? I would be interested to see what compression is after it has ran on the water for a ride. I always crank my machines over in the spring with the spark plugs out and plug wires grounded just in case. It’s a good habit

Yes I did, but with a harbor freight compression gauge, 90 psi.

If you end up rebuilding the carbs make sure they are genuine mikuni kits, I always buy mine at OSD Marine, the back to OEM kits. And re use your old spring, I’m pretty sure the spring on the 657x is impossible to get now, but either way, just make sure not to throw out the old spring

Took the air cleaner assembly, someone has definitely tampered with or rebuilt the carb at some point. Hopefully it was a mikuni kit. Honestly enjoying this process! May have to buy myself a XP or spx to tinker with

 

[mikidymac]

Alright, here’s what happened, I borrowed a Snap On compression gauge from a friend. Mag cylinder 130 pto 128. Thought to myself that it should run, did some more research, found a thread that talked about the engine being flooded with oil after sitting. Pulled the plugs, let all the oil squirt out, and she fires up! Will be doing gas lines and carbs now that I know it runs. Here’s everything else I found out, Im restricted to premix due to the previous owner JB welding the oil inlets on the rotary cover and the pump. Wear ring is in great shape! Hopefully with a carb kit I’ll be out on the lake.

Hang on!
Do you still have the oil lines to the rotary gear?
If you can't get oil to the rotary gear the engine will be ruined especially with leaking inner crank seals. You have to supply the rotary cavity/gear with oil, no way around it. You are going to have to pull the fittings, clean out the JB Weld and reinstall them. Then supply oil with either the oil tank or the "Looped Hose" method.

 

[1986toyotapickup]

Hang on!
Do you still have the oil lines to the rotary gear?
If you can't get oil to the rotary gear the engine will be ruined especially with leaking inner crank seals. You have to supply the rotary cavity/gear with oil, no way around it. You are going to have to pull the fittings, clean out the JB Weld and reinstall them. Then supply oil with either the oil tank or the "Looped Hose" method.

Hold up, are you talking about the two fittings that go to the crankcase? Those are alright. I'm talking about the 2 little nipples that get oil from the pump and go into the intake. Rotary Valve Cover Replacement Exchange for Sea-Doo Wouldn't premix get oil to the rotary cavity? While running the oil lines to the crankcase? Sorry for all my questions!

 

[mikidymac]

The oil pump and 2 little fittings are just for the rotary valve, cylinders and crank so premix is fine.
The two large lines on the crankcase lube the rotary shaft and gear.

 

[burtshaver2021]

Yes I did, but with a harbor freight compression gauge, 90 psi.

Took the air cleaner assembly, someone has definitely tampered with or rebuilt the carb at some point. Hopefully it was a mikuni kit. Honestly enjoying this process! May have to buy myself a XP or spx to tinker with

I thought I remembered you saying you were going to change out the gray fuel lines, good idea. I would clean the micro filter in the carb and if it’s running good; I wouldn’t even rebuild the carbs, but if it’s not working as it should in the water then I would go ahead and rebuild the carbs at that point, I’ve heard that simply cleaning them never works and it’s true, I’ve tried multiple times to just clean them and both times I ended up rebuilding them, but as I said if it’s running perfect at all throttle positions I wouldn’t spend the 169.00 for a rebuild kit. If when on the water it doesn’t run perfectly, stop driving immediately and fix it, don’t try and run it, in the hopes that it will clear itself up.

 

[1986toyotapickup]

I thought I remembered you saying you were going to change out the gray fuel lines, good idea. I would clean the micro filter in the carb and if it’s running good; I wouldn’t even rebuild the carbs, but if it’s not working as it should in the water then I would go ahead and rebuild the carbs at that point, I’ve heard that simply cleaning them never works and it’s true, I’ve tried multiple times to just clean them and both times I ended up rebuilding them, but as I said if it’s running perfect at all throttle positions I wouldn’t spend the 169.00 for a rebuild kit. If when on the water it doesn’t run perfectly, stop driving immediately and fix it, don’t try and run it, in the hopes that it will clear itself up.

The oil pump and 2 little fittings are just for the rotary valve, cylinders and crank so premix is fine.
The two large lines on the crankcase lube the rotary shaft and gear.

Thank you guys so much for the tips, I truly appreciate it. Just a couple of things that i want to confirm before I order the oil pump block off plate. When looping the crankcase oil lines, do I install a ball valve on the input line to stop possible crank seal leaking during winter? How do i get the nylon gear out that powers the pump? How do I bleed the crankcase oil lines?

 

[burtshaver2021]

I believe you need to take the air box off, intake manifold off, believe there’s a gear in the back of the intake manifold to take off but not sure. I’ve never had a 657x apart, took a Quick Look at the manual but never sure until you’ve done one. You can find free manual at seadoomanuals.net section 7 . No need to bleed the loop for the rotary valve, just fill the hose with oil and air will come out the other side where your vent hose is attached beneath the exhaust , you should have some type of check valve that will allow air in and out at a few pounds for expansion and contraction .

 

[mikidymac]

You don’t need to buy anything.
The intake nipples have been plugged with JB weld. Just pull the intake and remove the nylon oil pump gear and reinstall and I suggest a new o-ring.
For the rotary valve gear a ball valve on the intake side isn’t a bad idea if you suspect leaking crank seals. Nothing to bleed on the rotary gear as it self bleeds.