95' xp carb questions.. clean filters with carbs still in ski or do I have to remove.

[JKSTI&R1]

Hey guys,

So quick question. Can I pull the sides off the carbs in my 95' xp and clean the filters or are they on the insides of the carbs?
like can I get to them, or are they on the inner sides of the carbs? Also, im not to sure about the whole "pop off " thing, but i Think it has something to do with the spring in the carbs right? So if thats true, cant I, if I rebuild them, just use the original spring and not have to worry about the pop off pressure? The black springs that are in there are 85g I think and the new silver ones are 65g. So if I dont change the settings on the ski, just replace things, wont it be like it was before or am I missing something? I will be doing a full rebuild in the off season, but we have family coming out this week and Im not sure i want to pull the carbs and do all the things I was going to do during the off season. We took it out today and it is bogging and have to play with the throttle to get it to go, so I think its the fuel filter in the carbs, I just want to pull off the plates and clean the filters and be done for now. we have about a month of our lake season left and dont want to have a ski down for the rest of the little time we have left....... Thanks for the help guys :thumbsup:

 

[Sportster-2001-951C-Stock]

Hey guys,

So quick question. Can I pull the sides off the carbs in my 95' xp and clean the filters or are they on the insides of the carbs?
like can I get to them, or are they on the inner sides of the carbs? Also, im not to sure about the whole "pop off " thing, but i Think it has something to do with the spring in the carbs right? So if thats true, cant I, if I rebuild them, just use the original spring and not have to worry about the pop off pressure? The black springs that are in there are 85g I think and the new silver ones are 65g. So if I dont change the settings on the ski, just replace things, wont it be like it was before or am I missing something? I will be doing a full rebuild in the off season, but we have family coming out this week and Im not sure i want to pull the carbs and do all the things I was going to do during the off season. We took it out today and it is bogging and have to play with the throttle to get it to go, so I think its the fuel filter in the carbs, I just want to pull off the plates and clean the filters and be done for now. we have about a month of our lake season left and dont want to have a ski down for the rest of the little time we have left....... Thanks for the help guys :thumbsup:

I kinda don't think you can get to them, can't do it on my 951, they're too close together. But you're welcome to try, I just don't think you can without taking the carbs completely off.

The filter is item #22 in this drawing, it's shaped like a thimble, just a bit smaller. about 1/2 as large and there's one in each carb:

http://fiche.seadoowarehouse.com/se...asp?Type=18&make=seadoopwc&a=278&b=9&Action=O

How about your selector switch, does the ski lean-bog in the reserve position? Have you checked the water separator cup to make sure it's not lose? The o-ring when oiled won't curl up as much when putting the cup back on, it screws on and off. If there's an air leak there, the fuel pump will suck air. Item 17 in this drawing:

http://fiche.seadoowarehouse.com/se...sp?Type=18&make=seadoopwc&a=278&b=14&Action=O

And yes, you want to reuse your springs so don't lose or damage them.

 

[Mekanix]

Yes you have to pull them off to do it right.

You could do it in the the hull by removing only the aft carb but its still hard to do.

Best thing is to pull the carbs out and disassemble them where you can see everything.
You can build a pop off tester pretty easily and its important for the first 1/4 throttle.
Usually you would re-use your original springs. They come in 65,80,95 and 115 gram.
The mikuni kits usually contain the 65 and 115 springs.


First thing to do is to get a manual for that model. Then download the Mikuni SBN manual, It helps to explain whats going on inside them and all the parts/ assembly order.
The whole process takes about 3 hours with the carbs out and back in. And thats with new kits and building a pop off tester.

 

[JKSTI&R1]

Hey thanks for the reply's. Ok yeah you guys are right. I got the one side open and the filter was clogged but the other carb is on the inside so out they come. The ski doesnt have reverse but it boggs at open throttle, it idles fine, starts fine, but my daughter had the throttle full open and it wouldnt go. She had to feather it to get it to go. We were out for about an hour and a half and it got better, but not perfect. I will pull them out. I have 6 rebuild kits I bought for the down time, so I will just rebuild it. The ski also still has the damn grey lines, so im sure that is also causing a problem. I will reuse the springs and figure out how to build a pop off tester.....

Speaking of springs. I rebuilt the carbs on a 96' gtx and the kit came with silver springs, so i used the silver one cause they were new. Is that going to cause a problem? Im about 95% done with the gtx, new fuel line, cleaned the selector, empty fuel and oil tank and put in new. I tried to bleed the oil lines, but it came out in a nice flow so dont know if there is any air in the lines. When I start it I will manually hold the oil pump open to make sure..... Thanks again for the help with my noob questions .

 

[Mekanix]

Depends on how soft the new spring is compared to the old ones. You would need to check the pop off on that one too. Your probably going to find its too low or too high depending on which spring it was. The kits I've used have the 65 and 115 in them, and the carbs needed the 80 so I re-used the ones that came out each time or bought the right ones.

If you used the soft ones you might find that its rich for the first 1/4 throttle. if you used the taller one it would be lean.


Standard automotive 1/4" black fuel line, 25' should leave you with a few feet left. There's a 99.995% chance those grey lines will break down and clog the filters again in no time

 

[JKSTI&R1]

OK, I know on the gtx the spring was softer than the original spring. So do I just adjust it to the new spring? Is that where the pop off test will come in to play? Or do I have to pull it out and put the old spring in?

So on the XP, I got the carbs out, both filters were clogged. So I rebuilt them both and cleaned them and put them back together. I m going to put the new fuel lines in while I have it all apart and clean the selector and the fuel filter thing ( I think its the water separator ) tomorrow when I get up. How am I going to tell if its too lean or rich? To much smoke or not enough or fouled plugs or if I set the pop off right, will it run as it should?

 

[Sportster-2001-951C-Stock]

OK, I know on the gtx the spring was softer than the original spring. So do I just adjust it to the new spring? Is that where the pop off test will come in to play? Or do I have to pull it out and put the old spring in?

So on the XP, I got the carbs out, both filters were clogged. So I rebuilt them both and cleaned them and put them back together. I m going to put the new fuel lines in while I have it all apart and clean the selector and the fuel filter thing ( I think its the water separator ) tomorrow when I get up. How am I going to tell if its too lean or rich? To much smoke or not enough or fouled plugs or if I set the pop off right, will it run as it should?

"She had to feather it to get it to go."

Yeah, it's lean, lack of fuel. You don't want to do that very long b/c lack of fuel also means the lubrication isn't flowing properly and the fuel cools the pistons, as well. A little too rich can be okay as long as it's not running badly and fouling plugs but too much fuel offsets the oil:fuel ratio so you could potentially run into a lubrication issue if it's really rich, so do everything you can to get it close to factory setup and then go from there if it's still not acceptable.

There are four different metering springs available and several different size brass fuel inlet metering orifices as well, to arrive at the correct pop-off combination which basically helps control the fuel mixture at low throttle positions from idle to 1/4 throttle and these are often chosen to achieve fuel flow by factory engineers based on the airbox/flame arrestor dynamics(air box design has some effect on the negative pressure in the carb bore).

So you're best off to shoot for the spec'd pop-off, a weaker spring will make the low throttle range a bit richer, so if it's not too rich you might be okay but if you find it's flooding out with too much fuel in the lower throttle range you might have to put the original springs back in there. The low speed idle mixture screw might have to be turned in a bit more with those weaker springs than the factory spec to achieve a reasonable idle mixture. but if the pop-off spring is too weak it will receive too much fuel in the low range. The diaphragm metering regulator works on engine vacuum, and without vacuum (as the engine is slowing down, vacuum reduces, and engine off is no vacuum) the metering needle shuts off flow to keep fuel from flowing into the intake manifold and flooding the engine. A too strong spring will cause inadequate fuel supply because the vacuum won't be strong enough to pull on the diaphragm into the chamber and open the metering needle.

The inlet metering needle loses effect at higher throttle positions when the engine is running, much above 1/4~1/3 throttle it loses it's effect b/c the metering arm moves to full open position due to the increased vacuum signal in the carb bore, this is where the fixed jets control flow. There is a high speed mixture screw for the large venturi which can be used to supplement the fuel flowing through the main high speed jet, above 70% throttle the fuel flow through this variable orifice(HS screw) is in parallel with the fixed jet orifice.

You shouldn't have any lean bogging issues if the tiny holes in the carb bore are clean and gum free, carb solvent through them while disassembled should remove any gum by spraying it through the brass two jets under the kidney shaped metering plate in the fuel chamber.

Often, it's just a clogged filter, but gum formations can also cause fuel starvation as well so while they're off, I clean everything up.

Spray carb solvent through those two brass jets and make sure it comes through the holes well, in the carburetor bore, not good through one and a trickle through the other kind of thing.

So to do the job the right way and avoid any possibility of having to remove the carbs a second time, the pop-off should be confirmed before installing the metering diaphragm, otherwise a problem can go undetected until the startup then a complete disassembly has to be done to correct the issue if one exists.

Generally, assuming no assembly problems exist, you can just throw the original springs back in there and get away with that but I check pop-off myself, just to be certain.

 

[JKSTI&R1]

Hey thanks for the great response. I will check the pop off on the gtx. Its not too hard to pull the carbs and the ski is for my dad, so I want it right the first time when he gets it. I found this at harbor freight for $10..... It looks like it will do the trick...... The tires stem ending screws off so i can put what i need there instead.....

I Google how to check pop off and it looks not to hard, just a question? Do I leave out the diaphragm right or leave it in?

 

[JKSTI&R1]

Ok just got done testing one of the carbs and it is reading 31-32 psi. I have checked around and some say thats fine while others say 40-56? I used the same spring but one of my other 95' xp has a black spring but this one was silver. The kit came with a silver one also but the spring was way weaker than the factory one I took out ( or at least the one I took out of the carb before I rebuilt it ) So do you think maybe my other xp had a silver spring but was turned black because of age?

 

[JKSTI&R1]

Ok, just got done with the other carb and man I could shoot the person who had the ski before me. the carbs have been rebuilt before, so I guess that explains the silver and not black spring, and they stripped 4 different screw while putting it back together. I had to use my screw extractor to remove them, thankfully I had other carbs im working on so I can replace the screws tomorrow from ace. Anyways the pop off's are different. Is this normal? The carb with the pulse is at 31-32 psi while the other carb is 43-44 psi. Did I do something wrong?

 

[Sportster-2001-951C-Stock]

They both should pop the same, as close as possible. If they both have the same springs in them but way different pop then check the one that's low and make sure it's got the 1.2 metering needle seat in it. Otherwise if close but not quite, the metering lever may be bent on one of them. The carb with the pulse is the carb that has the common fuel pump mounted in it.

According to this chart, you should shoot for 40psi pop off:
http://www.seadoosource.com/carbreference.html

There are four springs:
Silver 65gram
Silver 95gram (wound in opposite direction of other three)
Black 80gram
Gold 115gram

Which seat orifice do you have in your carb? Selecting the appropriate seat and spring to match your pop off target, looks like a spec of 40psi pop-off with a 1.5 seat you could use the 95gram spring or if 1.2 seat would need the 80gram spring.

Pop-off is measured without the diaphragm installed, and some lubricant on the metering needle, such as WD-40 or other light machine oil so test results are more consistent between the three repetitive tests.

The pop-off procedure and the table of anticipated spring/seat combinations are given in the Mikuni manual:
http://www.mikuni.com/pdf/sbn_manual.pdf

If it ran well before at some point in time, I would keep the same calibration combination unless there was a compelling reason to change.

It's late and I'm fading fast, so gotta go..

 

[JKSTI&R1]

Hey Guys,
Ok so im all done with the xp and I go to start it and its not getting fuel. I bought nice clear lines for the main 2 fuel lines so i can see if I have fuel or not. But it wont suck up fuel from the tank, no matter what position I have the selector on. I have the main lines going to the bottom of both carbs. It looked like it was right with the arrows pointing, bottom arrow poiting in and top arrow pointing out. Did I do it wrong? And I took one line off at a time so I wouldnt mix up the lines. The ski runs when I put fuel/oil mix in the cylinders...... What did I do wrong? Also I ran a straight line on the main lines, got rid of the straight little connectors that were in the original line, I heard that was ok because they are only straight 1/4 connectors..........

 

[JKSTI&R1]

Ok, never mind. I am an idiot and got the lines crossed up in the front compartment....... Sorry, but hey, i just like talking with all of you guys.........:thumbsup: