717 single carb Help

[rkkoeb]

I need some help with carb setting on a 97 GS 717. I purchase two of these jetskis and took them up north for the first time. One ran outstanding and the second one started off good but then had issues. It was bogging all the time and when I pulled the choke it would kill the engine. I am going to pull the carb apart and rebuild them completely include replacing all the jets. I did notice a difference for some reason between the two jetski carbs. The one that ran good has no fuel pump but the one that has issues does. not sure why. Either way I need to know the correct jet sizes and what the set the two fuel screws at and what to look at that may be causing my problem 150 PSI on both cylinders and the grey fuel lines have already been replaced in past. Any help would be great

Rick

 

[rkkoeb]

I need some help with carb setting on a 97 GS 717. I purchase two of these jetskis and took them up north for the first time. One ran outstanding and the second one started off good but then had issues. It was bogging all the time and when I pulled the choke it would kill the engine. I am going to pull the carb apart and rebuild them completely include replacing all the jets. I did notice a difference for some reason between the two jetski carbs. The one that ran good has no fuel pump but the one that has issues does. not sure why. Either way I need to know the correct jet sizes and what the set the two fuel screws at and what to look at that may be causing my problem 150 PSI on both cylinders and the grey fuel lines have already been replaced in past. Any help would be great

Rick

 

[WhiskeyD]

Do you have the service manual? All the questions you asked are answered in it.

 

[rkkoeb]

I will have to look tonight when I get home. I know I have one for a 97 GSX I believe and not sure if all the 97 models would be listed in there?

 

[Spider4real]

All models should be in there. But if required you can download it here:

1997 SeaDoo Manuals - FREE PDF Download!

 

[rkkoeb]

Perfect thanks… I do have another question I see for the two GS models I have one carb has an accelerator pump on and the other doesn't. Is there a reason why and does this change the carb settings at all?

 

[awdunn]

[My experience rebuilding [2] 97 GTIs with the 717 engine... ] I think your two skis have diff carbs because at some point, one was replaced with what was available. -- 97s did not have an accel pump. 98's onward did. It appears the 97 carb verson is no longer available - or at least I cannot find one. All new carbs for that model include the pump. Here's another person in this situation: "1997 seadoo gti carburetor type" ... ALSO, the replacement carb sold at OSD "OSD Sea Doo 717 OEM Mikuni Replacement Carb with Accel" says, "Even if your Sea Doo didn't originally come with an accelerator pump, this one will work" -- // The carbs sold have the same body, but the jetting and adjustments are slightly different --
1997 SeaDoo GTI Carb# 270500297 BN-40I (SB) MAIN-175 PILOT-67.5
Needle 1.5 Spring 270500267 Pop 23-43 Adj LOW- 1 HIGH- 1-1/2 - no accel pump
1998 SeaDoo GTI Carb# 270500328 BN-40I-38 MAIN-167.5 PILOT-70
Needle 1.5 Spring 270500313 Pop 36-40 Adj LOW- 1-1/4 HIGH- 0 - has accel pump
ALSO, the low speed orifices are slightly different - in addition to the hole controlled by the low mixture adjust screw , the 97 has 3 tiny holes, the 98 only 2.
See Sea Doo PWC Carburetor Reference
-- Now why the diff? I am supposing that Rotax, Mikuni, and SeaDoo engineers made the changes as an improvement [see OSD description. The OSD page does not list that carb as a repalcement for the 97, but the body and cable mounts are identical.] --- One more note -- there appears to be a "California version" where the low and hi mix adjustments are semi-permanently capped off with a brass cap [adjustment screws are underneath and not available for adjusment.] I have purchased such version in the past and it workd off the shelf with no adjustment just fine, but my preference would be to have the adjustment available.

 

[rkkoeb]

Ok I went through and clean the carb and took it for a ride today. Not bad but for sure have a mid level bog. I have not replaced any parts in the carbs yet just cleaned it. I think I will order a carb kit but does anyone have an idea on why I have a mid bog?

 

[awdunn]

Suggest a genuine Mikuni kit... On a recent pair of 96 SeaDoo 2xcarb each rebuild, my client supplied [4] 3rd party kits he purchased, so I put them in. All bench tests for all 4 carbs were good; dry runs on trailer were good. But in the water, neither boat could accelerate much past idle without killer bog - but accelerated better with half choke [=lean bog] SO, I rebuilt all 4 carbs with genuine Mikuni. In doing so, I paid particular attention to differences in the kits. TURNS OUT, the 3rd party check valve [#12 on the Mikuni part list - and past which all fuel passes] was .010 thick from the 3rd party kit, vs the Mikuni being much thinner at .002 thick [same as human hair - and so more flexible. NOT particularly noticeable without a caliper!] After the Mikuni rebuild, both boats ran great in the water - making me think that the thicker - and stiffer - check valve just let less fuel past the check valve body. ===== POINT IS, even though yours seems to be a RICH bog - a cheap 3rd party carb kit can have unforeseen issues [even when bench and trailer tests are good.]
Good luck!

 

[rkkoeb]

I just order a rebuild kit from OSD. I just picked up this jetski so never had it on the water until a couple of days ago so not sure how it ran before. I agree OSD kits are the only way to go so hopefully this will take care of my issue. should I replaces the plunger on the accelerator pump also when I have the carb pulled apart?

 

[awdunn]

KITS - Be aware, "OSD" kit is not same as "Genuine Mikuni" kit - OSD sells both - that being said, OSD is pretty reputable and trustworthy, and the OSD kits contain some bonuses [carb top gasket, socket screws to replace JIS [japan phillips-like] screws], so I'd say if you purchased OSD kit, you are OK. PUMP - if it works, 6's. However, there is a school of thought that says - you have it, use it, to preclude any wear or defect you cannot see.
==== A TWIST - WHILE carbs are off, IMHO, it is wise to remove the oil pump flange and measure the RV clearance. My pure guess is, better than half of older SeaDoo RV covers are worn past specification. With carb off and end of season is the ideal time to remedy that, otherwise it will haunt. [not cheap, but worth the investment.] Download a shop manual, it will tell you how. Get a set of angled feeler gauges [amazon, cheap.] Attached is a pic of a 97 GTI with RV cover out of spec. [Spec is 010-014, pic shows one at 018.
Oil pump flange fasteners [the lower two] are not particularly frendly to remove, helps to have some metric ball-end allen keys [mine have 1/4"drive on the other end, peachy!] 3rd pic below shows that tool reaching the RV cover bolt [also a pill to reach], arrows point to 2 of 6 oil pump flange bolts [4 are easy to get, 2 more are way underneath.] Good luck, have fun!

 

[rkkoeb]

The kit I order is a Genuine Mikuni kit. Only ones I use for years now

 

[Venturian1]

I need some help with carb setting on a 97 GS 717. I purchase two of these jetskis and took them up north for the first time. One ran outstanding and the second one started off good but then had issues. It was bogging all the time and when I pulled the choke it would kill the engine. I am going to pull the carb apart and rebuild them completely include replacing all the jets. I did notice a difference for some reason between the two jetski carbs. The one that ran good has no fuel pump but the one that has issues does. not sure why. Either way I need to know the correct jet sizes and what the set the two fuel screws at and what to look at that may be causing my problem 150 PSI on both cylinders and the grey fuel lines have already been replaced in past. Any help would be great

Rick

If it’s idling ok and runs good at the top end, but lagging at midrange, check you pop-off pressure, and do it with the round diaphragm out. A small hand held pressure / vacuum pump from harbor freight works fine for this. You need to plug the fuel return outlet with a finger or rubber cap,
I leave the diaphragm cover off, and pour a little 2-stroke oil over the needle and seat and watch for bubbles to see if anything leaks while pumping it up, but wear safety glasses. 30 psi is what I like, and is achieved by using the proper spring under the arm. If two carbs, make both the same.

 

[mikidymac]

The OSD "Kits" are not the same as the Genuine Mikuni "kits" only in that the Mikuni kits come with a lot of parts that are not used. OSD makes his kits with only the parts you actually need and he uses only Genuine Mikuni parts in his kits.

 

[rkkoeb]

OK update: Rebuilt carb using OEM kit. Low setting at 1.25 turns and high at 0. Pop off pressure is at about 35, was getting 60 so I changed the spring. Pressure test carb and no leaks. Jetski has new OSD rectifier and a new coil and plugs. Compression on motor is 145 on both cylinders. Started off running great for about 10 minutes then issues again. top end is good but now when I punch it starts off great until about mid rang and then bogs down to the point it will kill the motor but doesn't happen all the time. W
hen it bog does if I back off and feather the throttle this it helps out. What can be my issue?

 

[rkkoeb]

my other jetski the twin to this one doesn't have the carb with the fuel accelerator on and runs great

 

[rkkoeb]

Bump

 

[rkkoeb]

I just read this on the carb link. Does this make sense as this is what is happening to mine

Motors that have the accelerator pump on the carbs cannot take off from a standstill without a big hesitation followed by normal acceleration, or the engine just dying out completely, causing you to need to restart it.

 

[Jenks13]

Swap the carbs out and if the good ski then bogs, its the carb. If the good one runs good then its something else. Possibly cavitation or a fuel line issue like a small air leak.

 

[mikidymac]

I just read this on the carb link. Does this make sense as this is what is happening to mine

Motors that have the accelerator pump on the carbs cannot take off from a standstill without a big hesitation followed by normal acceleration, or the engine just dying out completely, causing you to need to restart it.

If the accelerator pump isn’t working then yes, they will be really bad off idle when taking off and can even die. They a jetted much leaner than the carbs without the pump so when you don’t get that fuel squirt they aren’t getting enough fuel to get going.

 

[rkkoeb]

how can I test the accelerator pump to see if it is working correctly? I heard there is a check valve, location and how can I test or clean it? Can I replace the accelerator pump with a new one or does it only come with a new carb?

 

[rkkoeb]

I also just found out there is a small restrictor inside one of the small hoses coming off the accelerator pump. I know I replaced these lines and never new about this restrictor. Can this be my issue and if so how can I get a replacement one?