Greetings to all. I hope someone can help me with this.
I have a 92 XP with twin carb 587 engine - hull no. ZZN2484A292 pwc. (The motor appears to be a 91, not 92) This motor has the rotary valve cover (RVC) with the oiling lines running from the bottom of pump to the top right of RVC and from the top of the pump to the bottom left of the RVC as pictured below and as pictured in every friggin' manual photo I can find! The RVC is numbered 810 038 and has a divided circle with the numbers 9 & 91. (I think this is the manufacturer's date code for Sept 91?)
(see 91RVC photo attached)
I also have what i believed to be a 93 XP twin carb 587 spare parts motor. (can't verify by tag at top of mag cover as it is gone.) This motor has the same 810 038 part number RVC as above and it's divided circle has the numbers 8 & 93 (August 93?) This is a very different RVC. The oiling lines go from the pump top and bottom to lines nozzled directly into the left and right ports as opposed to the surface oiling holes used in the setup described above. In other words, this RVC has the same surface type oiling holes located in the same position (offset from the ports and spreads lube across surface) but the castings were not ever drilled there.
(see 93RVC photo attached)
Here's the what and why I need to know. The 91 RVC is pretty grooved and worn and needs replacing. The 93 looks much better and I like the idea that maybe this was an improvement in the part over time and the oil was (should have been) routed into the ports. The casting of the part number 810 038 hasn't changed but it no longer gets oil routed to the old slot style ports in the surface but directly into the port. Both engines used the same intake manifold and carbs but the throttle cable pulley on the 93 was front mounted and much bigger than on the 91. The 93 RVC has "odd" porting that appears to be larger than the 91 RVC. The obvious question now is can I use this 93 RVC on my 91 engine with either set of carbs and intake? Does any of this make sense?
I'd appreciate any help. Thank you.
Dave
I have a 92 XP with twin carb 587 engine - hull no. ZZN2484A292 pwc. (The motor appears to be a 91, not 92) This motor has the rotary valve cover (RVC) with the oiling lines running from the bottom of pump to the top right of RVC and from the top of the pump to the bottom left of the RVC as pictured below and as pictured in every friggin' manual photo I can find! The RVC is numbered 810 038 and has a divided circle with the numbers 9 & 91. (I think this is the manufacturer's date code for Sept 91?)
(see 91RVC photo attached)
I also have what i believed to be a 93 XP twin carb 587 spare parts motor. (can't verify by tag at top of mag cover as it is gone.) This motor has the same 810 038 part number RVC as above and it's divided circle has the numbers 8 & 93 (August 93?) This is a very different RVC. The oiling lines go from the pump top and bottom to lines nozzled directly into the left and right ports as opposed to the surface oiling holes used in the setup described above. In other words, this RVC has the same surface type oiling holes located in the same position (offset from the ports and spreads lube across surface) but the castings were not ever drilled there.
(see 93RVC photo attached)
Here's the what and why I need to know. The 91 RVC is pretty grooved and worn and needs replacing. The 93 looks much better and I like the idea that maybe this was an improvement in the part over time and the oil was (should have been) routed into the ports. The casting of the part number 810 038 hasn't changed but it no longer gets oil routed to the old slot style ports in the surface but directly into the port. Both engines used the same intake manifold and carbs but the throttle cable pulley on the 93 was front mounted and much bigger than on the 91. The 93 RVC has "odd" porting that appears to be larger than the 91 RVC. The obvious question now is can I use this 93 RVC on my 91 engine with either set of carbs and intake? Does any of this make sense?
I'd appreciate any help. Thank you.
Dave
