95 SPX Needle Size

[eavega]

Hi all

I am trying to bring a 95 SPX back to life. First step was to replace the fuel lines and rebuild the carburetors. Therein my problem lies. I have disassembled the carburetors, and found that they have 1.5 needle valves. I've read a bunch on the interweb that recommends that these skis have the 2.0 needle valves. I have no history of how this ski ran when it had the 1.5 needle valves. I'm also fairly sure I damaged the seat trying to get it out of the carb in the first place (took a lot of grabbing, twisting, and pulling to get it to break free). I WAS trying to be careful to not push the pliers all the way down to where the needle would actually contact the seat, but I am not sure I was successful. There are no obvious scratches down at the bottom though.

So, my question: Should I
1. rebuild the carburetor, use the needle/seat that was in there and hope it was the right one and I didn't damage it getting it out in the first place.
2. Rebuild the carburetor, replace the needle/seat with the same sized 1.5 I found in there.
3. Rebuild the carburetor, replace the needle/seat with the 2.0 that the online information seems to point to being what is supposed to be in there.

Do the needle size even matter? Is it more of a case of the right pop-off pressure for a given needle/seat size for the engine? I'm not totally clear on the importance of the needle/seat size. I've only previously worked on motorcycle and outboard carburetors which don't use springs and popoff pressures. Those carburetor needles rely on floats to get the needles to open and close at the proper time.

I'm at the point now that I am ready to order the rebuild kits and needles if necessary, so any guidance or suggestions would be appreciated.

Thanks in advance.

Eric

 

[WhiskeyD]

http://www.seadoosource.com/carbreference.html is normally a great source for seadoo carb info.. though it says 2.0 for your ski?

 

[racerxxx]

The parts fiche calls out for a 1.2 NS for a 95 SPX with a 657 engine. Seadoo part# is 270500263

http://osdparts.com/index.php?main_page=product_info&products_id=945

Part #24 on the diagram

http://partsfinder.onlinemicrofiche...=28&b=15&c=0&d=-CARBURETOR-ASSY.-W/-FUEL-PUMP

 

[1of500]

Next time push the seat out from the opposite side directly under where the fuel filter is

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[LKGrider]

When I pulled mine apart on my 95 SPX with the 657x motor it had 1.2 N/S in it

 

[eavega]

So I sent a direct message to an online retailer that I eventually bought the rebuild kits from. He checked the HIN to verify which n/s were needed, and he told me it was the 2.0. Cost of the kit with the needles was the same, you just needed to specify the needle size. I would assume he had no reason to lie to me. Going with the 2.0 n/s and hoping for the best.

Thanks for the the information received.

-E

 

[1of500]

2.0 is way too big

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[racerxxx]

2.0 is way too big

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Hence the reason I posted the size and part number. I went right ti the micro fiche and got it. I've found several mistakes in that carb reference Web page over the last few years.

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[WhiskeyD]

The single carb motors use a 2.0 but it makes more sense for the dual carb 657x to have 1.2s

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[eavega]

Thanks for the additional information. I too looked up the parts catalog and cross referenced the SeaDoo part number and found it specifies 1.2s. What WhiskeyD says makes total sense with reference to the single vs dual carb setups. Since I have ordered the kits already I guess I need to fight with the online retailer to see if I can get the right N/S. Just for my own reference what would be the engine behavior if the N/S were too large? Too small? I'll assume the popoff pressure needs to be the same regardless of N/S size used?

Again, thanks for the help. I really want to get this right, as this ski is going to have enough problems without having to chase ghosts.

Rgds

Eric

***UPDATE***

Retailer made good, he checked out the reference as well as the parts catalog and did indeed find that the part number indicates the 1.2 mm N/S, so he is shipping me out the right needles free of charge. Apparently he referenced the Seadoosource.com table, and it is wrong. He has asked them to update the information there.

-E

 

[eavega]

One more question for the assembled...

What is the popoff pressure? The manual indicates 16-21 PSI, se Seadoosource.com chart indicates 22-27 PSI... The Mikuni carburetor chart doesn't indicate what the popoff pressures are on the 1.2 mm needles...

Thanks again for any help.

Rgds

Eric