Carburetor Adjustments

hfgreg

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#26
Agreed Bill, any posts should be adding to the content of this thread. We may need to get a better system down for the How to sections.
 


blown1993

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Raleigh NC
Water Crafts
1998 GSX Limited and a 1997 GSX
#27
Bill,

does this hold true for every seadoo out there including 947's? You said the low speed screw farther out is richer. I believe the manual says opposite.

I believe on the 947, only the low speed screw and the idle stop screw is accessible.

I am still sort of confused on what the low speed screw is really doing. Sounds just like a slow jet to me, why have both.

Just the other day I set mine to the factory spec of 2 turns, next try out, the ski died and one spark plug was black and soaking wet, the other looks nice light brown.
 

93 SPX

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Michigan
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Two 93 SPX and One 98 xp
#29
:thumbsup:Thanks for your posting on Carburetors...I do have one question. How can I know that my carb needs a rebuild or if it is just a adjustment issue? I have a 93 SPX that idles fine, but does not rev really high in water. I have adjusted the high speed screw in small increments, but the engine does not seem to run any different at all at one full turn each way.
 

Bills86e

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Sea Doo 95, XP, SPX, GTX,
SPI, XP, 97 Polaris Hurricane
#30
Thanks, but this thread is for members READ ONLY. PLEASE POST/START a new thread in the forum, as that is where our members can ask & get ANSWERS quickly !! Everyone is wecome into Seadooforum.

DO NOT POST IN A STICKY


You can easily start a NEW THREAD at forum, the top left button, OR you can send a member a personal message.
 
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bthacker

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Tennessee
Water Crafts
1998 GSX Limited
#32
Thanks Bill for this post, It is very informitave and has help to clear up several questions and gave me a better understanding of how this type of carb works and when each jet and adjustment is in use.
I have a problem with my 1998 GSX Limited. It has a hesitation from about 1/4 throttle to about 3/4 throttle (runing rich). Have cleaned it twice without help(With Kits). I am going to replace the jets because the carb has been apart before I got it and not sure if it has the proper jets in it or if the jets that are in it has been tampered with but I am getting several different answers to what size jets should be in it.
1998 GSX Limited with silver engine.

SeaDoo Spec book shows 80 Pilot and 160 Main
SeaDoo WareHouse shows 82.5 Pilot and 165 Main
Another parts Warehouse shows 82.5 Pilot and 165 Main
bhatch21 in another post states that it should have 75 Pilots and 162.5 Mains

You seem to be the person who would know. What is your suggestion on jets and what should the high and low speed adjustments be set at. The high speed adjustment is very hard to get to so I would like a specialests advice to get me close before going to the lake and working all day. Right now they are set at low speed= 1 1/4 turn out and the mains are all the way closed.

Thank You
Brian
 

RodInEscondido

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Water Crafts
2000 GTS
98 GTS
96 XP
94 GTS
91 SP
90 SP
89 SP
77 SeaRay Sundancer 25
#33
I hate to appear stupid here, but ... I see reference to carb cleaning and spray into "pilot jet". I looked at the Mikuni manual and see only low and high speed jets; would "pilot" be referring to one of these?

thanks,
Rod
 
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Location
Wheaton
Water Crafts
2007 Wake
1994 SP
1985 Four Winns
#36
Great info! I am rebuilding the carb on a 94 SP and the seloc manual doesn't have specs for high and low speed mixture screws.
The appendix has "idle speed" screw is 3/4 to 1 1/4 turns out. is it the same for the mixture screws? I should have checked them on disassembly.
 

Molotok

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NW Florida
Water Crafts
99 SeaDoo XP Limited
Previously owned 89 Kawasaki 650sx
#38
Mikuni Pocket Tuner (Mods remove this, if its somehow illegal)

Mikuni_Pocket_Tuner.jpg

Not as useful as having the actual sliding paper version, but should still help.
 
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Location
florida
Water Crafts
1995 seadoo gts
#39
Hello Im new in tho forum but i used your instruction for setting the carb in a 1995 seadoo gts that i swap the single carb set up to a dual car set up. I put a new engine last year and everything was working great. i use to turn the jet ski every month with no problems at all. The jet ski is practical new. I want to put dual carb and i find a set from a 1992 seadoo xp. The person rebuil the carb last year and he was using the jet ski last year too. Everything is in great condition. But i turn the engine and both carb work for 30 second but the one from the Pto stop. I take the spark plug out and the pto side they are flooded in gas and the one for the mag are ok. i check the spark and both cylinders have spark. I adjust the carb almost to close and still puting to much gas in that cylinder. I clean the needles high and low in both and i clean the diaphragm in both carb too, just to make sure. But again both star working find both the one for the PTO stop.

So im looking for ideas what can that be. Spark is good. Needles are clean. low and high are set withing spec. What else it could be.
 
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Location
Rochester, NY
Water Crafts
1997 Seadoo XP
#40
I just bought a 1997 XP with K&N air filters installed on the carbs by the previous owner. I want to switch them out for the stock air filters so water will stay out better. I am new to jet skis and will probably roll it a few times and get water in the hull (I hear the XP is not good at keeping water out).

I also want to service/rebuild the carbs and the mounting screws are cover by the K&N bracket so the carbs cannot come out until the brackets are off.

I am having trouble getting the mounting bracket for the K&Ns off the carbs. There are two 5mm hex screws holding each bracket. I have got one of the 4 out and stripped another one (hopefully I'm not screwed).

I have long and standard hex sockets but the standard are too short to reach the screw past the bracket and the long are too long and the hull interferes with the socket. I also tried to use handheld "T" hex wrenches but cannot get enough torque to get the overtightened hex screws out and am afraid of stripping them.

Any suggestions?

carb1.jpg
 

Attachments

countryboy

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australia
Water Crafts
honda dory and a seadoo 97 xp
#41
hi just hoping u can help me as i have just got a 97 xp seadoo and it is cutting in and out after half stick and what is that lil pump looking thing on the rear of the motor that is hooked up to ur carbs
 

Bills86e

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Sea Doo 95, XP, SPX, GTX,
SPI, XP, 97 Polaris Hurricane
#42
PLEASE................................................POST YOUR QUESTIONS IN THE GENERAL FORUM< Below the STICKIES!......................................

NOT HERE
 

mike23

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Location
ohio
Water Crafts
1997 seadoo spx, 95 seadoo SP
1979 searay 21ft
#43
I have a 97 SPX that runs fine at full throttle and idle. but won't run at half throttle is this an adjustment problem?
 

sselzer

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Location
Springhill Florida
Water Crafts
96 Seadoo SPX 97 Seadoo GSX
#45
I just redid my whole 97 GSX. It's having a starting issue, it will start for a few seconds then stall whether or I give it gas. When if check the spark plugs they are soak with gas and oil " I run premix" I also believe their some assembly lube still in the bottom of the case. What do I adjust so that the engine doesn't flood anymore?
Please give me simple instructions.
Thanks,
Sean
 

Bills86e

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Sea Doo 95, XP, SPX, GTX,
SPI, XP, 97 Polaris Hurricane
#46
Always leak-down test your carb(s) After reassembly. Yours are leaking, so replace the needles and the seats.

To do a leak-down, pump pressure into the inlet nipple and put your finger on the outlet, pump up til a few psi's short of pop-off setting.
If it holds five minutes, the carb passes, and now its ready to go on the motor. If you have a rv cover in proper spec, the ski will be easy to lake tune. Use WD-40 when adjusting your needle lever. Read the Sticky, watch the vids, or go to Mikuni's website.
 

Bills86e

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Water Crafts
Sea Doo 95, XP, SPX, GTX,
SPI, XP, 97 Polaris Hurricane
#47
Please everyone, POST your questions in the two stroke seadoo forum, These STICKY's are only for reading, How-To, ECT.
 

sselzer

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Location
Springhill Florida
Water Crafts
96 Seadoo SPX 97 Seadoo GSX
#48
Always leak-down test your carb(s) After reassembly. Yours are leaking, so replace the needles and the seats.

To do a leak-down, pump pressure into the inlet nipple and put your finger on the outlet, pump up til a few psi's short of pop-off setting.
If it holds five minutes, the carb passes, and now its ready to go on the motor. If you have a rv cover in proper spec, the ski will be easy to lake tune. Use WD-40 when adjusting your needle lever. Read the Sticky, watch the vids, or go to Mikuni's website.
I installed new needle and seats. Don't have the knowledge to do all that other stuff. Thanks
 
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Location
North Carolina
Water Crafts
2002 GTI LE
2007 Sportster 155hp
2007 RXT
#50
Hi Bill, I have a 2002 GTI LE with the 717 engine, and it runs up to 20-22mph then may jump up to 42mph but then won't run faster than 22mph. It starts without any throttle, just using the choke and idles well after it warms up. I replaced the regulator/rectifier (the square black module attached to the MPEM) and I still have the same results. I had a defective MPEM (blown diode due to jumping the battery 2 years ago) I replaced the diode which fixed the MPEM and installed it and I still have the same issue. I would appreciate any additional troubleshooting that you can offer. I have all new fuel lines, fresh gas, cleaned fuel filter and even added inline filter, cleaned the selector valve, removed the fuel baffle from the gas tank and cleaned it and assured all ports are clear. I installed new spark plugs and a new coil with wires and spark plug boots. The front cylinder measured 120psi and the rear 125psi compression test. The carb has been rebuilt by me and a long time Seadoo mechanic, I am stumped!
Thanks!!
 

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