wmazz

All the watercraft manufactures build their watercraft to withstand customer abuse.

Every year manufactures send riders out to ride their new watercraft nearly every day to
discover problems that may occur to a customer. Their constant testing allows them to
gain many more hours on the skis before the customer.Then manufactures send out service
bulletins, in advance of the problems occurring to the customer. Well run service departments
will fix those problems ...

Note: These instructions have been modified for bn 38mm round body carbs on a reed engine.
It assumes you have the correct impeller for your particular set-up. Read the entire thread if you
do not understand



Idle drop test
(1) Perform the idle drop test on a trailer. Set the low screw set to a rich setting. For example:
1 ½ turns out, and warm up the engine (Sam you may need a leaner initial setting between 1
and 1 1/4 turns ...

The article will be based on the assumption the watercraft is in good running condition before changes
are made. The simplest method is rejetting an oem set of carbs with the intention to correct a problem
or to increase acceleration. The worst mistake is to perform changes to your jetting or attempt "reverse
jetting" as part of a rebuild, or in conjunction with other pump, and, or engine modifications without first
developing a functional baseline to work ...

Evaluate your fuel screw settings
After you have found your initial settings, it is time to reevaluate the success of your jetting. I normally strive to
achieve a ¾, ¾ turns out on my pilot and hi-speed screws. In order to estimate changes in my jetting, I use
as a rule of thumb “¼ turn equals a jet size.”

I recommend you make it a habit to strive for pair settings of (¾, 3/4), (1, 1), (1 ¼, 1 ¼). The main reason
for this is to be able to recognize a problem ...

Jetting Basics
First off, jetting isn’t always increasing a main jet, arbitrarily changing the needle seat diameter, or
modifying pop-off psi to somebody’s standard. Jetting is all about creating or maintaining a balance.
This balance applies to any type of carburetor, and always begins with the pilot circuit. The pilot circuit
is flowing fuel 100% of the time, and the low speed circuit creates a balance between the pilot screw
setting, low ...