My 1996 SPI Resto

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Back to working on this project, Carb is off to clean and it was pretty dirty :
IMG_20180526_170946.jpg
Got all the corrosion off and cleaned up pretty good though and the other pulse side where the little filter is was quite clean, even the filter was ok.

Unfortunately, one of the 2 inner screws I need to take off is stuck and stripped, even tried notching with a dremel and using a bladetip but wont budge and is stripped worse now. Other screw under the muck came off easily and I have the proper screwdriver as well. Tried soldering iron heat trick and also lots of PB blaster over 2 nights. Looks like I'll have to drill the head off and hope I can extract the rest of the fastener.

Are there 1 or 2 jets underneath?
 
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Finally got the screw out! thought I would try one more time and use a cordless drill and more pb, tightened a bit and then unscrewed with my weight on it. Now to wait for the screws on order and finish cleaning. Looks like 2 jets underneath, a small one and a bigger one.
 
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Picked up the screws today that the auto parts place brought in for me(Metric M4 philips head fastener 14mm long), .30 cents each (they're stainless steel as well). Local Sea Doo dealer wanted $8 each! Part number for the Mikuni screws just in case anyone needs them in the future is "C5=0414-G" but the M4 14mm ones fit as well and are much cheaper. Pics of the carb after removing stripped screw :
spi carb jets.jpgspi carb jet cover.jpg
 
Carb is back together, looked at the oil injection lines and they are original so out they come. All the local places seem to not have tygon line at all but another type that's everywhere, translucent yellow, made by Oregon who states :

  • Oregon Fuel Line is a specially formulated gas and oil vinyl tubing - made
    for use with lawnmowers, chain saws, and snowmobiles
  • Maintains air tight seal on fittings - even in extreme temperatures
  • Translucent material resists swelling or hardening
  • Compare to Tygon
NON-COMPLIANT with EPA and CARB regulations

Oregon Part Number: 07-261
 
Hey man... you did a great job with that. I sure didn't think that screw would cooperate but you out lasted it and WON !! :D
 
Picked up the Tygon line at Home Depot and installed, cleaned out the fuel selector valve, changing fuel lines and am wondering about the vent line - do I need to change it and do I need to test the check valves in the two ends of the vent line setup? As I understand, these are the only check valves in the fuel line system in the SPI.
 
I recently replaced my gray vent lines only because I was having problems. I wouldn't worry about the gray lines but if you do... be gentle with the fittings. I cut the gray lines off because I knew I would break them if I kept struggling with them The valve check is simple.... just apply a little pressure they shouldn't leak. They only allow air in one direction.
 
Don’t clean the fuel valve, replace it.
The fuel selector valve? Mine wasn't dirty actually and it was functioning but I put some cleaner thru it anyway. Have seen others say theres were gunked up.Why do you recommend replacement instead of cleaning and would that be only if its gunked up?
 
No, they are 20 years old and the rubber inside rots and it sucks air. Cleaning them only makes it worse. If you are pulling air your are not flowing fuel.
 
No, they are 20 years old and the rubber inside rots and it sucks air. Cleaning them only makes it worse. If you are pulling air your are not flowing fuel.

Thanks for the explanation, will order a new one.

How about the vent line check valves, does one let air in (top?) and the other hull side one let air out?
 
That is correct. Some of the ones on the side are actually a pressure relief and pop at about 3 psi.
 
Ready to put carb on today, the 2 intake to carb nuts I have are non self locking with lock washers - Mikuni manual states use flat washers with self locking (nylocks?) nuts. Mine were not very tight when I undid them, guess nylocks are beat to retain torque and flat washers better to clamp evenly the carb to intake.
 
That is correct. Some of the ones on the side are actually a pressure relief and pop at about 3 psi.
Hmmmm..... when I applied pressure to the carb return line the air would come back out the return line. It was pressuring up the fuel tank. I didn't read how much pressure was on the fuel tank though. but it seemed strange to me.
 
Ready to put carb on today, the 2 intake to carb nuts I have are non self locking with lock washers - Mikuni manual states use flat washers with self locking (nylocks?) nuts. Mine were not very tight when I undid them, guess nylocks are beat to retain torque and flat washers better to clamp evenly the carb to intake.

THe factory uses lock washers and standard nuts. You will be fine
 
Hmmmm..... when I applied pressure to the carb return line the air would come back out the return line. It was pressuring up the fuel tank. I didn't read how much pressure was on the fuel tank though. but it seemed strange to me.

All of the ones I have seen pop at 3-5 psi except the HX. For some reason is just has a check valve going in under the seat area and a check valve going out at the bond line so the tank doesn't hold any pressure.
 
I will give that a try. I sure thought it was strange. If the tank pressures up won't that slow down the return line and back pressure the carbs? If this happens would this pressure be enough to decrease fuel flow? I'm just asking but we loosened the gas cap when having problems and it had no effect. We had other issues but this may still be a lingering problem.
 
So after carb cleaning and istall the SPI started up fine and I ran for 15 seconds 4 consecutive times so all seemed well. Cold started it 4 days later and ran fine and stalled after 15 seconds and wouldn't restart anymore. Pulled carb and rechecked everything including taking out needle seat this time and checked needle which looked fine. Re-installed and was hard to start and when I finally got it restarted had to keep applying throttle to keep it going, lots of smoke and oil and gas out the exhaust.

Is this a needle and seat issue? Was running fine when it would start the other times but after I checked the seat this time its running rough and needs throttle to keep it going.
 
Sounds like leaking needle and seat.
1. Did you use only Genuine Mikuni parts?
2. Did you pressure test and popoff test the carb?
 
Sounds like leaking needle and seat.
1. Did you use only Genuine Mikuni parts?
2. Did you pressure test and popoff test the carb?

Yes, genuine Mikuni parts, and no popoff done as I don't have the tool/gauge.

Needle and seat are original, is there a way to fix if they're sticking which would be the issue for them leaking possibly? Saw online some fixes by polishing inside seat and the outside of needle to stop them sticking/leaking.
 
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