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RSRBOB, Technician
Category: Boat
Satisfied Customers: 1074
Experience:  Former Yamaha Factory Service Rep, Dlr Line Tech, Serv Mgr, G/M
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I have two 1990 kawasaki js 440 stand ups, does any oil go

Customer Question

I have two 1990 kawasaki js 440 stand ups, does any oil go in the motor besides the mix? for example like a motorcycle, gear oil, motor oil, primary drive chain oil etc, also they have been sitting for several years winterized, what should i check for upon using again?
Submitted: 6 years ago.
Category: Boat
Expert:  shane j forrest replied 6 years ago.
The engines in those should be 2 strokes.You will mix the oil with the fuel for the engine lubrication.Go to your local Kawasaki shop and find their water craft 2 stroke oil and on the back of the bottle it will give you mixing instructions.
Customer: replied 6 years ago.
yes i knotow this but it is hard for me to believe that the bottom end has no source of lubrication....your tellin me the mix will lubricate the crankshaft, and all bottom end bearings?
Expert:  shane j forrest replied 6 years ago.
Yes the fuel in the crankcase mixed with the oil is plenty of lubrication for the the bottom end. Unlike a 4 stroke where the fuel only enters throught the intake valve and then in the combustion chamber the fuel in a 2 stroke enters the intake and then the carnkshaft basicly takes it and pushes it up in to the intake port of the sorry i trying to make it sound as simple as possible I hope this helps.
Customer: replied 6 years ago.
aritre sounds good not tryin to break your balls just looking to get rid of em and dont want to sell crap...last question shane, one runs and starts if i put the mix directly into top of carb, checked fuel lines they are not clogged (i think... there are four of them and one has a one-way valve, reserve, reg, return and the last i know not) took carb off and apart to check for blockage didnt find there something i am missing? the other runs fine but idles high thinkin either gunk in it or choke stickin...thanx for your help
Expert:  shane j forrest replied 6 years ago.
The line that your not sure about is probally a roll over valve.the roller over valve is designed to prevent water from getting back in the fuel tank once the water craft is tipped over. do a compression test on the engine you have to pour fuel down to get started. the engine has to have good compression for it to be able to pull fuel through the carburator into the crankcase.If the compression is good then check to see if you have fuel to the carburator.If there is fuel present there then take carburator apart and look for debris or a problem with the float if equipped.
Customer: replied 6 years ago.
shane i appreciate your help but you gave me all info that i already knew....
Expert:  RSRBOB replied 6 years ago.

The lines coming out of the tank are in fact On, Reserve, Vent (w/roll over valve) and Return. The On and Reserve lines go into the petcock, and the fuel supply line for the carb comes out of the petcock, goes through the fuel filter/water separator and into the carb.

One common problem on PWC carbs that have been sitting is the float needle gets stuck in the needle valve seat. These carbs are a floatless design, and depend on engine vacuum, fuel pressure and atmospheric pressure to lift the needle valve off the seat. If it becomes stuck, the normal forces exerted are not enough to move it, so you must un-stick it manually. That would require taking the carb apart and either pressing on the opposite end of the float arm or removing the pivot pin for the float arm and pulling the needle out of the seat, then putting it back together.

Also, make sure the vacuum line from the intake to the fuel pump on the carb is connected and not cracked or split. It is a pulse type fuel pump that depends on the positive and negative pressures generated in the crankcase to pump fuel to the carb from the tank.

If the ski that is running has a high idle but it is not in the water, that is normal. When the jet pump that drives the ski is in the water, it creates a load that will bring the engine speed back down to a normal idle.

These carbs do use a legitimate choke, not a fuel enrichening circuit, therefore if it were sticking, the ski would not want to run past start up, so that is highly improbable that you have a sticking choke. There is an idle speed adjustment on the side of the carb, where the throttle cable attaches to the pulley, that you can adjust the idle speed with, but you should only adjust the idle speed with the ski sitting in the water.
If you have any more questions, feel free to ask.


Edited by RSRBOB on 11/2/2009 at 1:32 AM EST
Customer: replied 6 years ago.

thanx for the info...i had the carb apart and the needle jet along with the pivot arm was not stuck, but there was a metal plate, screen, and gasket that was held together by two screws, (i am assumming it is where the fuel is directly injected into the carb due to there is a small hole in a brass piece that leads into carb) and the gasket was so dry that i could not remove it to see what was im wondering is there anything that could block fuel flow and or possitive pressure under that gasket? i did not want to take it out for fear of ripping it and then having to travel to kawi!!! so lastly i ask if then this is not the case and the fuel lines are not clogged, and none are cracked, and the lines inside the tank are not broken, cracked or clogged, what could possibly stop flow? and both do run ive had them running

Expert:  RSRBOB replied 6 years ago.
Here is a link to a diagram of the carb. Please use the reference numbers to describe what you are afraid to take apart.

And it is not the float arm that gets stuck, it is the needle that it lifts.

I understand both are running. One you have to pour gas down the carb to get started, the other idles high.

Customer: replied 6 years ago.
36 37 38 39, sorry used wrong word
Expert:  RSRBOB replied 6 years ago.
OK, those components should not cause the symptoms you are experiencing.

My next question would be have you double checked the routing of all the hoses connected to the carb? The easiest way to do that in your case would be to compare the running one to the non starting one.

Next, the fuel has to come in through the cap, #51, and then work its way down through the check valves, #47, then out to the perimeter and pass through the holes around the edges of #41 -#48 and into the fuel chamber area.

Also, I would advise removing the fuel screws and shooting carb cleaner and compressed air through those passages to make sure they are open. Again, set the fuel screws in the same position as the running ski. Set position is defined as the # XXXXX turns out from a LIGHTLY seated screw. Fuel screw adjustments are made in 1/4 turn increments, and specs can also be described as 1/4 turns as well.


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