Hello, I'm getting pretty frustrated trying to solve a new problem with my 2000 XP at high RPM here in Phoenix after rebuilding carburetors and adding adtermarket reeds. I've looked at many, many posts for bogging or high rpm problems but the ones for XP are mostly older ones with smaller motors or DI model 951's like GTX which often have different problems that come with the high pressure fuel. I'm going to dump a lot of info...
The main lake I ride at is at 1600ft so I would think it runs a bit rich since they set these up at sea level? I was told the Seadoo was bought new in California. This is not a pwc I just bought or do not know the recent history of- I've fixed many issues on Seadoo's and Waverunner's I've owned over the years since my first in 2015. When purchased from a long time owner I was told there was 25 hours on a rebuilt motor after his friend submerged it without clearing the water + running hard again to dry out. A local shop did the work and also replaced the grey fuel lines. Everything appears to be stock other then I use a Lithium-Iron Shorai battery that is more powerful and much lighter. The oil injection system has had Seadoo XPS it's whole life (was told) and I switched over to Lucas oil full synthetic a couple years ago for lower cost and so I don't have to use different oils in all my 2-strokes. I have put 60 hours on it in six years with good throttle response and no engine problems besides not revving past 6000 rpm all the time the last year or so. I decided it was time to rebuild the carbs anyways and maybe that would let it rev out a little further. I bought genuine mikuni kits BN46I and new mikuni jets and seats 2.0 after seeing a little wear on the the sealing tip. The internal filters looked fine and no parts in the carb were bad besides the hard to remove gaskets. I didn't change the low speed screws as they had caps with stops (didn't want to break+no low speed problems in past) and the high speed ones I returned to the same number of turns after replacing o-ring. I used the same springs that had been in the carbs after reading many posts about it. I did the blue spot facing the right direction on the clear diaphrams from what I read. The small lines from the accelerator pump were hard and brittle plus leaking after removing the carbs before the kits so I replaced them with Tygon fuel line. The accelerator pump squirts good when the arm is mechanically pushed by the throttle linkage. I rolled the dice on pop off pressure as I don't have a tool to check- that is mostly affecting low speed throttle response? Well I get out on the water after the rebuild and there is slow accelaeration off the bottom up until 3-4k rpm where it starts to get on plane and then it is better down to about 2.5k rpm. I took about three 20-30 minute rides and high rpm throttle response was great all the way to 6500+ with about another 5 mph then last year (GPS speedometer installed). I can at least go out with friends and figure the low rpm issue later (I installed some Carbon Tech reeds at same time so might be rich on bottom I've heard). Well, at the end of the day I figure it's safe to head to the other side of the lake. I cruise along at a steady 5-5.5k rpm for maybe 5-10 minutes and there is a complete bog. I figure may be low on gas so I switch to reserve- no change. It runs but as soon as you hit higher rpm of about 4-5k there is a big bog for a second or two then will surge ahead then bog and so on. I went to shore, looked over everything and added another 2 gallons of gas. I waited about 30 minutes and went back out but the problem persisted. I rebuilt the RAVE valves last year and double checked they move freely, no leaks in line and the check valve to the crankcase works after the bogging problem (didn't check solenoid yet but since I had good top end that wouldn't seem to be the issue). Since the carbs worked pretty well for almost 90 minutes that shouldn't be the bogging problem? Could it be a fuel supply problem? Pulling choke out a little right before or at bog doesn't improve things (kills motor) so hopefully not a lean condition. The reserve switch I've heard is a problem for many- does that cause a bog? The rear cylinder plug looks dry, light brown and normal while the front one looked wet and smelled a bit like fuel. Spark plugs were new about 8 engine hours ago. It runs fine out of water and idles around 2-3k. In the past I needed to use choke to keep it from revving too high out of water (another reason I rebuilt carbs). The fact it ran pretty well for over an hour after the carbs were rebuilt is the thing making me scratch my head. Is this some new problem or should I focus on carbs? I have lots of experience with quad and dirtbike carbs but these are very different!
The main lake I ride at is at 1600ft so I would think it runs a bit rich since they set these up at sea level? I was told the Seadoo was bought new in California. This is not a pwc I just bought or do not know the recent history of- I've fixed many issues on Seadoo's and Waverunner's I've owned over the years since my first in 2015. When purchased from a long time owner I was told there was 25 hours on a rebuilt motor after his friend submerged it without clearing the water + running hard again to dry out. A local shop did the work and also replaced the grey fuel lines. Everything appears to be stock other then I use a Lithium-Iron Shorai battery that is more powerful and much lighter. The oil injection system has had Seadoo XPS it's whole life (was told) and I switched over to Lucas oil full synthetic a couple years ago for lower cost and so I don't have to use different oils in all my 2-strokes. I have put 60 hours on it in six years with good throttle response and no engine problems besides not revving past 6000 rpm all the time the last year or so. I decided it was time to rebuild the carbs anyways and maybe that would let it rev out a little further. I bought genuine mikuni kits BN46I and new mikuni jets and seats 2.0 after seeing a little wear on the the sealing tip. The internal filters looked fine and no parts in the carb were bad besides the hard to remove gaskets. I didn't change the low speed screws as they had caps with stops (didn't want to break+no low speed problems in past) and the high speed ones I returned to the same number of turns after replacing o-ring. I used the same springs that had been in the carbs after reading many posts about it. I did the blue spot facing the right direction on the clear diaphrams from what I read. The small lines from the accelerator pump were hard and brittle plus leaking after removing the carbs before the kits so I replaced them with Tygon fuel line. The accelerator pump squirts good when the arm is mechanically pushed by the throttle linkage. I rolled the dice on pop off pressure as I don't have a tool to check- that is mostly affecting low speed throttle response? Well I get out on the water after the rebuild and there is slow accelaeration off the bottom up until 3-4k rpm where it starts to get on plane and then it is better down to about 2.5k rpm. I took about three 20-30 minute rides and high rpm throttle response was great all the way to 6500+ with about another 5 mph then last year (GPS speedometer installed). I can at least go out with friends and figure the low rpm issue later (I installed some Carbon Tech reeds at same time so might be rich on bottom I've heard). Well, at the end of the day I figure it's safe to head to the other side of the lake. I cruise along at a steady 5-5.5k rpm for maybe 5-10 minutes and there is a complete bog. I figure may be low on gas so I switch to reserve- no change. It runs but as soon as you hit higher rpm of about 4-5k there is a big bog for a second or two then will surge ahead then bog and so on. I went to shore, looked over everything and added another 2 gallons of gas. I waited about 30 minutes and went back out but the problem persisted. I rebuilt the RAVE valves last year and double checked they move freely, no leaks in line and the check valve to the crankcase works after the bogging problem (didn't check solenoid yet but since I had good top end that wouldn't seem to be the issue). Since the carbs worked pretty well for almost 90 minutes that shouldn't be the bogging problem? Could it be a fuel supply problem? Pulling choke out a little right before or at bog doesn't improve things (kills motor) so hopefully not a lean condition. The reserve switch I've heard is a problem for many- does that cause a bog? The rear cylinder plug looks dry, light brown and normal while the front one looked wet and smelled a bit like fuel. Spark plugs were new about 8 engine hours ago. It runs fine out of water and idles around 2-3k. In the past I needed to use choke to keep it from revving too high out of water (another reason I rebuilt carbs). The fact it ran pretty well for over an hour after the carbs were rebuilt is the thing making me scratch my head. Is this some new problem or should I focus on carbs? I have lots of experience with quad and dirtbike carbs but these are very different!
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