Carb replacement questions:

[Pale Rider]

hey Tom! what`s up!


1998 Challenger 1800
carb model: Mikuni Diaphragm BN-40i-38 with accelerator pump

factory specs:
Main jet MAG: 142.5 PTO: 145
Pilot jet 67.5
Adjustment Low-speed 1-1/2 turn ± 1/4
High-speed screw 0

I have been told that these NEW 40mm Mikuni replacements from WSS can be used with little modification on the 98 challenger 1800. I`m just guessing that it is the fuel lines orientation as those carbs have the fuel pumps attached. I have just a fuel supply end plate and no pump on the MAG carbs... These are listed for the 97 and 99 model year but NOT the 98 1800.
http://www.watercraftsuperstore.net/.../714HP002.html

specs:
MAG side carb has the following:
Low jet 67.5
Hi jet 140
needle valve 1.5
arm spring 95 gram
low speed screw set at 1.25turn out
hi speed closed

http://www.watercraftsuperstore.net/.../714HP003.html
specs:
PTO side carb has the following:
Low jet 67.5
Hi jet 142.5
needle valve 1.5
arm spring 95 gram
low speed screw set at 1.25turn out
hi speed closed
Accelerator pump added to PTO carb

To make these replacement carbs work is it just a simple jetting change to the factory specs?
I can deal with the fuel supply changes by reusing my fuel supply end plates/caps, and removing the pumps on the carb body`s. ( I have remote fuel pumps).


Thank you...PR...

[Pale Rider]

Re: Carb replacement questions:

bump?

[Technical Support]

Re: Carb replacement questions:

Hey Andy how’s things, I have used the replacement carbs from the superstore on a 96 xp and when removing the accelerator pump I also changed to the original jetting and all worked very well. I think the only reason the jetting is different is to compensate for the pump.

[Pale Rider]

Re: Carb replacement questions:

Hey Andy how’s things, I have used the replacement carbs from the superstore on a 96 xp and when removing the accelerator pump I also changed to the original jetting and all worked very well. I think the only reason the jetting is different is to compensate for the pump.

Hey Tom! From what I`m reading the original OEM carbs fuel supply/return fitting orientation is exclusive to the boats with remote fuel pumps. And the replacements more geared towards the ski`s. Besides re-jetting I would just need to swap over my cable brackets and fuel supply end plate and sort the fuel lines. The jetting could also be heavier/richer in the boats maybe bc of load/heat compared to the much lighter ski`s. but to play it safe I would just jet to factory spec.
My carbs are spotless inside and function well, it`s a shame that the original fuel supply T snapped off The MAG carb and the PO sent it out for a quick fix. I hear this is common.
Ok, Thank you Tom, for replying and verifying/confirming the replacements can be used. This will be food for thought and a good option to install new with a few simple changes... Thanks Andy...