2000 RX - Accelerator Pump

[KyleW2]

Just bought a 2000 RX ski this weekend and before I even attempt to start it, I’m pulling the carbs and rebuilding (still had tempo lines)

I’ve done some reading on removing the accelerator pump on the 951s - looking for some opinions on this! If anyone has any suggestions, tips or advice - I’m all ears.

Thanks!

 

[mikidymac]

I would keep it and make sure it works.

 

[KyleW2]

Pulled the carbs apart today and unfortunately I’m missing the restrictor jet for the accelerator pump. I know this jet isn’t available anymore. Any thoughts? Can I just use a normal jet in the line?

Also - I’m actually shocked this ski was running recently with the carbs looking like this.

 

[etemplet]

I took some measurements on that orifice a while back but I doubt it I could readily find it. I'm not sure the purpose of the orifice in the line, be it to limit the amount of fuel allowed to the pump or help the pump retain its prime. I've had many issues with these accelerator pumps the most prevelant one is the nozzles spraying into the carb throats becoming clogged. I've only been able to unclog them by using a small drill. The fix is borderline destruction so I have to be really careful. Each nozzle has a check valve which must be properly functioning. I spend a good bit of time on these when I have them. Pain in the azz but when you get them working all is good. I don't remember exactly but I think an 80 low speed will suffice for the elimination of the accelerator pump assuming the normal size is 75 so.... (5) up for what you remove. Take all of this with a grain or three of salt. You'll have to do your own research. Hope this helps a bit. Good Luck.

 

[KyleW2]

Did some digging and I think I’m going to delete the pump, but leave the stock air box on. Problem is most of the info I’m finding is for adding ProK filters instead, trying to avoid that though.

 

[etemplet]

I'd definitely leave the stock air box in place. I got my info from a guru. If I was going to delete the accelerator pump, I'd pull the low speed jets, add 5 to it and give it a water test. Anyway... good luck.

 

[KyleW2]

After some additional thinking I decided I’m going to keep the accelerator pump. I did some reading and found that a size 60 low speed jet will work in place of the restrictor that wasn’t in the line, so I’m going to try it out. I tested the accelerator pump today and it pumps fuel, but since I have it this far apart I’m going to go ahead and put a new diaphragm in it.

 

[etemplet]

After some additional thinking I decided I’m going to keep the accelerator pump. I did some reading and found that a size 60 low speed jet will work in place of the restrictor that wasn’t in the line, so I’m going to try it out. I tested the accelerator pump today and it pumps fuel, but since I have it this far apart I’m going to go ahead and put a new diaphragm in it.

Let us know if you can find a diaphragm. Personally I wouldn't mess with anything that is working. Good Luck !!

 

[KyleW2]

Decided not to replace the diaphragm - however it does look like OSD sells it.

Does anyone happen to know the fuel line size that feeds the accelerator pump?

 

[mikidymac]

1/8" but make sure you pull the restrictor out of the orifice and put it in the new line feeding the pump.

 

[NCGator25]

1/8" but make sure you pull the restrictor out of the orifice and put it in the new line feeding the pump.

What about the fuel line size coming from the fuel accelerator to the carbs? I replaced it with 1/8 line that I picked up at Oreillys, but seemed to be too big as I was getting air in those them. I've changed to 3/32 also from Oreillys, but I'm still getting a little hesitation below 3000 rpms when it's supposed to be kicking in.

I've already adjusted the screw that controls the accelerator arm that engages the pump.

 

[etemplet]

I test the accelerator pump system before I install the carbs. I've had too much trouble with them not to and some of them require a lot of tinkering to get working properly. I don't like them but when the are working... they are great so.... I've never eliminated the accelerator pump yet. LOL

 

[KyleW2]

Interestingly enough, I keep reading that the line should be 1/8 but that line is extremely tight to get on on the inlet of the accelerator pump but the lines to the carbs feel perfect. It’s almost like it’s actually 3/16 line for the inlet on this particular carb

 

[JC-SUPERJET]

Maybe Hose Diameters are supposed to be Metric?

1/4" = 6.35 mm, NOT 6 mm

1/8" = 3.18 mm, NOT 3 mm

The 0.35 mm Diameter difference on the 1/4" Hose means that, if used as a Pulse Line from Crankcase to Carb, the Pulse line will not be snug enough to seal and will require a Metal Clamp to seal it. The Actual 6 mm Line will seal on it's own and a Zip Tie is enough to keep it in place.

 

[NCGator25]

I took my 2000 RX (carbed) out today and it wasn't running good so I brought it back in. I wonder if it's because of the smaller lines I installed after the accelerator pump. I think I may go back to the 1/8 line. I will order some better clamps for it too. I think the zip ties may be letting air into the system.

I'm surprised Sea Doo didn't mention the correct size of the lines in the service manual.

 

[KyleW2]

I took my 2000 RX (carbed) out today and it wasn't running good so I brought it back in. I wonder if it's because of the smaller lines I installed after the accelerator pump. I think I may go back to the 1/8 line. I will order some better clamps for it too. I think the zip ties may be letting air into the system.

I'm surprised Sea Doo didn't mention the correct size of the lines in the service manual.

Did yours have the in line restrictor?

If you don’t have one in there that could cause the problem.

For now I’m setting the ski back to stock but if I have running issues I’m rejetting and bypassing the accelerator pump completely. Only reason I didn’t do that yet is I don’t want to use aftermarket flame arrestors on this ski.

 

[NCGator25]

I haven't touched the inlet line. I left that one alone since it had the restrictor in it. I didn't want to open that can of worms.

I'm also wondering if the t-fitting that the fuel line from the pump connects to is damaged. It seems the PTO carb isn't getting the fuel to it from the pump like the MAG is. Looks like it isn't getting good flow to that side. I may replace it when I pull the carb out again.

Just wish I could find definitive info on the fuel line size. I've searched and searched, but can only find guesses out there on what it is for this carb.

 

[etemplet]

If it isn't squirting properly I'd look at the fitting on the carb and the nozzle. Apply some pressure VIA a hand air pump and determine if anything is coming out. I've had to go as far as drilling way into the nozzle to clear debris plugging the nozzle. It is so dang small it is difficult to clear. That fitting is also a check valve. Pair of vice-grips and a twist will easily remove it for thorough cleaning. Push it back in with Loctite 609 on the exterior.

Both nozzles should spray equally and easily when you actuate the pump VIA the lever.

Here is a picture of one of the sets I rebuilt Strangely these are on a 787 XP. All I use are Zip ties. Hope this helps.

 

[NCGator25]

Good tip on checking the nozzles prior to removing it. As suspected, the gas wasn't making it's way to the front Mag carb. I've pulled it out, and plan on going back to the 1/8in lines I had on it previously (like the yellow ones in your picture). I did some additional research on the line size, and found something from Dr. Honda that mentioned 1/8in size. I think he used to work on them.

Also, I was planning on replace the white t-fitting in your picture. I'm wondering if mine is cracked, and allowing air in. I bought a brass 1/8in t-fitting, but the white one has smaller holes on it. Not sure if that's going to make a difference or not. I figured the brass would be more durable moving forward. Here pics of what I'm attempting to use.

 

[BusyDad]

Hi guys, nice thread so far.
I’ve found (from guy on YouTube) that the “check valve” in the injector nozzles (pictured) is supposed to hold until 13 psi is reached and then spray.
Mine don’t seem to hold at all on the bench, thus allowing fuel to spray all the time.
After my rebuild, on my 97 xp, it idles great but only accelerates at first, then it completely bogs down with any throttle.
I did keep the restrictor in the accel pump supply line.(almost tossed it!)
I’ve not seen seen any instruction about setting up the accelerator pump with the adjusting screw. Enlighten me!

 

[NCGator25]

Interesting find! My guess is that you are referring to this video:

He mentions the Mikuni BN 40i series as the one's he's working on.

I have a 951 carb model, so it uses Mikuni BN 46i carbs. I haven't seen anything related to a check valve on these carbs. One of mine seemed to be clogged, but was cleared up after spraying brake parts cleaner into it. While spraying the cleaner, It didn't seem to have a restriction, which would indicate a check valve. But I could be wrong. Maybe others can chime in if they have the info on that. I'll look at the parts manual again later.

As for the accelerator pump adjustment, from what I've read, it should be adjusted so they are just touching. Just enough to make contact.