Shop Discount Sea-Doo Parts

To much oil, fouling plugs

Messages
123
Likes
15
Location
CO
Water Crafts
95 XP720 +3mm Bore
95 GTX657x +1mm Bore
#76
try not to get too worked up. these things can take a lot of tinkering around.

Signs still point to your issue being carb related. As Miki mentioned that needle needs to be replaced and based off those pictures you definitely should be replacing the diaphragm as well.

the best bet would be to order a full (and genuine) Mikuni rebuild kit for your carb(s) and replace everything. then pressure test and pop-off test again. While I think this will more than likely take care of your issue, at the very least you have 100% eliminated the carb as the issue if it does not (aside from tuning errors).
 


Messages
69
Likes
2
Location
central florida
Water Crafts
1998 Sea Doo XP Limited
2000 Kawasaki Ultra 150
#77
How about the lever arm? Is it level/flush with the carb body? It could be out of adjustment and still pass the pop off test.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#78
try not to get too worked up. these things can take a lot of tinkering around.

Signs still point to your issue being carb related. As Miki mentioned that needle needs to be replaced and based off those pictures you definitely should be replacing the diaphragm as well.

the best bet would be to order a full (and genuine) Mikuni rebuild kit for your carb(s) and replace everything. then pressure test and pop-off test again. While I think this will more than likely take care of your issue, at the very least you have 100% eliminated the carb as the issue if it does not (aside from tuning errors).
Needle seat and diaphragm on the way! Diaphragm would leak out of the carb into the hull but I ordered it anyway! See what the new needle and seat does. I'm reluctant to rebuild the carb AGAIN since all seams well but I'll see what the test bring back.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#79
How about the lever arm? Is it level/flush with the carb body? It could be out of adjustment and still pass the pop off test.
Yes level arm is flush! I'm seeing a quality rebuild on this carb and ready to move on to something else. New needle and seat on the way as is diaphragm but again the carb seams very sound. Had to order a new pop off gauge tester as I had a bad night lol but when it gets here the only thing carb wise I can think of is the accelerator pump. Diaphragm in it looked old but usable. Test will tell. Only place next to go would be weak spark.
 
Messages
69
Likes
2
Location
central florida
Water Crafts
1998 Sea Doo XP Limited
2000 Kawasaki Ultra 150
#80
If you end up having to test the spark, this 3 point spark tester should do the trick. I just picked it up recently to check one of my machines and it worked great. You can dial in the gap you want and determine the voltage based on how far the spark will jump. 3 point spark tester.jpg
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#81
Omg that's awesome! Waiting on parts and pop off tester for the carb but that's my next purchase! Doing a new wear ring on my xp so I have a couple things to do and parts on the way for both! I honestly shouldn't complain because I made it through most of the season. Just this GTI is killing me not being able to pin point the issue! Where is the best place to purchase that spark tester?
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#84
Ran all the carb test today and the needle and seat test didnt pass for leak. Was leaking 2 psi per 30 seconds starting at 10 psi. Would this cause my fouling issue within 10 minutes?
 
Messages
69
Likes
2
Location
central florida
Water Crafts
1998 Sea Doo XP Limited
2000 Kawasaki Ultra 150
#85
Yes, if its leaking past the needle or the o-ring for the seat. When you did the test, did you submerge the needle and seat in a puddle of wd-40 and see any bubbles coming up before it got to pop-off pressure?
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#86
I did but no bubbles. I'm gonna try better lighting tomorrow and check other areas as well.
 
Messages
69
Likes
2
Location
central florida
Water Crafts
1998 Sea Doo XP Limited
2000 Kawasaki Ultra 150
#87
If its losing pressure, its got to be going somewhere. Try putting soapy water on the pressure tester connections to see if its leaking there.
Another thought... Are the high and low adjuster screws in good condition? No ridges or worn spots where they seat? Maybe the extra fuel is getting past them.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#88
I'm gonna check all those places too and see. I have a new needle and seat coming today hopefully and I also have a rebuild kit on hand as well. I pulled the low needle and from just looking at it it seams ok but I'll check. My best guess is needle or seat because its leaking into the intake causing my rich condition. Also makes sense that after running it then letting it sit, it's even worse and drops a cylinder almost immediately. Plus the problem has gotten progressively worse with time as would the wearing of the needle or seat. Really hope I figured it out this time! Lol
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#89
Alrighty guys. Dumbstruck ass before me had a 1.5 needle in the carb when it calls for a 2.0. Think that was the issue.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#90
Ok so I put the 2.0 needle in and my pop off is at 20 when its suppose to be at 36-40. This mean the wrong spring is in?
 
Messages
69
Likes
2
Location
central florida
Water Crafts
1998 Sea Doo XP Limited
2000 Kawasaki Ultra 150
#91
I have the 1998 shop manual, not the 99. It calls for the 1.5 needle with the 95gram spring. The 99 might be different, but you might want to double check.
It also says 0 turns on the high speed adjuster and 1&1/4 plus or minus 1/4 for the low speed. Again, you'll have to double check that with the 99 manual
 
Messages
69
Likes
2
Location
central florida
Water Crafts
1998 Sea Doo XP Limited
2000 Kawasaki Ultra 150
#92
According to the parts diagram, the 99' calls for the 2.0 needle/seat. It also calls for a different spring than the 98'.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#93
High and low are set per manual. Apparently there was a spring made for the sbn40i that was 130 grams and no longer available as mikuni never made one only seadoo did from what I've read on threads. Check these pictures of specs out. Makes no sense. I'm having a rich issue so a bigger needle and seat with lower pop off makes no sense for me
 

Attachments

Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#94
Also have the option to go with 115 gram and try to run 32 pop off. I dont think the 1.5 seals all the way and is leaking fuel
 
Messages
123
Likes
15
Location
CO
Water Crafts
95 XP720 +3mm Bore
95 GTX657x +1mm Bore
#95
I would definitely double-check all of the parts you need for you specific ski.

I did think it worth mentioning though that sometimes the pop-off will be wrong even with brand new parts.

The way you would go about changing the pop-off pressure is to very slightly bend the arm that lifts the needle. the process is outlined in the manual.
 

mikidymac

Moderator
Staff member
Moderator
Messages
11,825
Likes
1,128
Location
California
Water Crafts
2003 GTI
2001 XP
1996 XP
1996 HX
1991 Superjet
2001 Superjet
#96
You need to be running the 2.0 needle and seat on your 1999 GTI and you can buy the spring directly from seadoo #270500428 or run the Mikuni 115gram. Your pop-off should be at about 32psi +-. Don't get too hung up on the 36-40 number in the book as it's probably a mispring from 1998 when they used the 1.5 needle and seat.
Also there is no 130 gram spring.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#97
Agreed. Got the needle in and have a 115 gram spring on the way. Gonna run thru my spark as well just to see if I find anything there before I put it back on the water. The 2.0 passes the leak test where the 1.5 does not so there was for sure an issue there. Any help on what to look for in the spark area would be helpful. It has a new coil and caps on it so long as the coil I got is working correctly, should be good to go.
 
Messages
64
Likes
2
Water Crafts
95 xp and 99 gti
#98
New spring and needle. Got around 34 on pop off. Works for me. Waiting for exhaust gaskets to finally test on the water. I'm gonna check spark before I go out though.
 

SPONSORED LINKS

Latest posts

Usergroup

Administrator Moderator Premium Member
Top