I have a 1995 Kawasaki JS750 ZXI Jet Ski. The previous owner removed the oil injection system with Oil Pump Block Off Plate and mixed it the gas 40:1. I was wondering if it is worth it to put the oil pump back on? Or if it would be better for the machine. If not what is the best fuel ratio to run, and is there anything I should check to make sure the owner did everything right when he took off the oil system?Also, my machine doesn't seemed like it is as quick or fast as it should be. Is there anything else I should check, Like impeller or reeds.
Russ

Russ, Reasons for removing oil pump is that Oil pumps can fail and You are able to pre-mix to a precise measurement as different oils offer different mixtures. I usually go 40:1 with standard oil and 50:1 with Synthetic oils.
  I would definitely check the Kawasaki impeller for nicks in the blades and the gap between the Jet Ski impeller and pump housing. If they have any issues that could defiantly cause a speed issue. Your ski is pretty old and I would recommend putting in some new reeds. I would do a head compression check and make sure all three cylinders are within 5lbs of each other. If they are more then 10psi between them you will need to do a rebuild top end piston kit.
​Ski Mechanic Tech Talk

I have a 2002 Sea-Doo GTX DI, It ran perfectly, and then I winterized it, and, after taking it out of storage, it lost approximately 5 mph. The engine only gets to 4000 rpm until its been run across the lake, then it loosens up and reaches 5500rpm. weird. Do you have any ideas? Do the exhaust ports need to be cleaned every so often?
Chris

Chris,
Sea-Doo recommends annual cleaning of the RAVE valve guillotine to remove carbon build up. But a bad water regulator valve, low fuel pressure or a jet-pump problem can also cause this problem.
Tech Talk

I'm wondering if you can help me with winterizing my ski. I have heard to put fuel  stabilizer in a full tank, partly full ect. Also make sure no water in system and put a bit of motor oil in each spark plug hole. Kind of a variety of efforts, and I'm wondering if you could help me in the correct way to winterize my jet ski?
Henry

Hi Henry, When winterizing a ski, I put fuel stabilizer in a full tank of fuel and run the motor to make sure that the fuel stabilizer gets into the fuel system completely. Then while ski is running, pour antifreeze into cooling system until it comes out at the exhaust, then squirt fogging oil into the carburetor until the motor stalls. This whole operation should take about 30 minutes with no water hooked up. Then you remove the spark plugs and poor about an ounce of motor oil in each cylinder and turn the motor over to make sure that the oil coats fully. Then you should check the pump for water under the cap and re-seal the pump if it has been exposed to water. Then you should lubricate all fittings and moving parts (steer, trim ect..)

​Tech

There is a difference in battery life between wet, sealed, gel and lithium batteries. A wet-cell battery is a good basic battery, but has its weaknesses. One problem is that these batteries are available in a wide range of quality, and price is not always the indicator of how good the battery actually is.
    These batteries fail mainly from non use, which causes permanent damage in the form of sulfation. Some better quality wet batteries have a chemical additive to help prevent this problem,but eventually the battery will be damaged. The other main problem is lack of maintenance keep the electrolytes to the proper level with distilled water.
  sealed Batteries are usually high quality batteries but may have a lower amp capacity compared to wet or gel batteries.The high the amperage rating, the more cranking power you have.
   Lithium & Gel Batteries are the best quality being a "maintenance free" battery, they don't suffer when ignored as badly as a wet battery. Of course you pay the price for this convenience.

Battery Chargers
The Best battery charger I have found for maintaining is a battery tender. It can be left on the battery indefinitely without damaging the battery like a trickle charger. For charging your battery use a maximum of 3 amps. High amperage chargers will damage your battery.
Tech Talk

Seizure occurs when the piston expands and sticks to the cylinder, stopping the engine. Lack of lubrication, a major reason for PWC engine seizure, occurs when fuel and oil are mixed in the wrong ratio, or your oil runs dry. Problems can also be caused by using cheap or non-recommended oils that do not have lubricating qualities required by PWC engines, Failures of oil injection systems are very rare.         Over heating is probably the most common cause of seizures. Other possible reasons for seizures are improper tuning of the carburetor; Advanced ignition timing; lack of cooling water; air leaks (causing lean mixtures) at the carburetor or intake manifold, head or cylinder gaskets, or crankshaft seals.
​  The way to prevent seizures is to have your carburetor adjusted properly by a professional mechanic then leave it alone, use good oil, and make sure your water cooling system is working. (keep an eye on the bypass-water should always be flowing when the engine is running).
​Tech Talk

Making adjustments to the Jetski carburetor air/fuel  mix is pretty easy. nearly all watercraft carburetors are fitted with high speed (30-100 percent throttle) and low speed 90-30 percent throttle fuel mix adjustment screws.  In a stock application the screw closest to the mounting plate of the carb is always the low speed screw; The one nearest the air intake is the high speed adjuster. turning them out (from bottom closed position) will richin the fuel mix.

The relationship between pop-off pressure and low speed jets. " those two circuits overlap" although the low-speed jet continues past 1/4 throttle engine operation, whereas pop-off pressure has little to no effect due to increasing air velocity in the carb. also, one can make up for slight inadequacies in the other.
"For example, if your pop-off pressure is a bit high, you can compensate by increasing the size of the low speed jet, The opposite is true, too: a slightly undersized low speed jet can be compensated for by using less pop-off pressure."

When does it become necessary to adjust the pop-off?
"Pop-off pressure refers to the pressurization of the needle valve with compressed air, through the fuel inlet," "this is a reference to the amount of pressure needed to open the needle valve-- or 'pop' it off its seat. The higher the pop off the more pressure required.

"When personal watercraft or Jetboats come from the factory they have fairly high pop-off, due to the fact that they also have somewhat restrictive air intake systems that cause the engine to generate very high manifold pressures. The higher the manifold pressures, the higher the pop off pressure required to properly regulate fuel delivery to the engine"

As you modify or change your flame arresters to a less re-strictive type ( meaning more flow), you are lowering this manifold pressure--- and are inadvertently creating a 'lean' condition in your engine. Changing the pop-off pressure--- which is nothing more then switching the Needle Valve Arm Spring in the regulator to a spring with a softer compression (gram) rating. "sometimes in order to achieve the desired pop-off pressure it's necessary to also change the needle valve size. Just remember its always better to use the smallest needle valve size to obtain the correct pop-off"
​Tools Use Pop-Off Gage

Remove the choke and replace its function with a primer kit. Though most PWC enthusiasts tend to regard the use of a carburetor primer as "band aid" for an ill tempered engine or comp device, it offers benefits for virtually any watercraft.The single biggest limitations to a carburetor operation is airflow; anything you can do to improve the flow (and velocity) of air through the carb will usually result in increased performance.  Choke assemblies, which incorporate regulatory devices similar in appearance to throttle plates (but located at the top of the carb) are an obvious impediment to air flow.

There have been a number of diffrent carburetors used to for feeding PWC over the years, primarily by mikuni, with the end result being the popular mikuni super BN carb. It is designed specificaly for watercraft -- meaning it is essentially a sealed unit that canot vent its fuel chamber to the atmosphere (which would allow fuel to leak into the hull in rollover situations).
 Though accurately tuning this (or any) carb for your application is limited by other possible weal linmks in the engine,  Use this procedure for calibrating tune-able circuits during testing - 
1 - Low Speed Adjusters: to adjust for smooth idle
2 - Pop-Off Pressure: just off idle to 1/4 throttle  ( in conjunction with low-speed jet).
3 - Low Speed Jet: just off-idleto 1/3 throttle
4 -  High-Speed Jet: 1/3 -to 3/4 throttle
5 - High-Speed Adjusters: 3/4 to wide open throttle

Learn how to change your Sea Doo pump oil in this easy to follow video.
​
For Sea Doo pump oil change you will need tools such as a 10mm open end wrench, 10mm socket, 13mm socket, Jet Pump Oil , Grease and O-ring if yours is damaged. If your o-rings are in good shape you can re-use them. 

​This Sea Doo pump maintanance should be done once a year.

The following video will work for all Sea Doo 2-stroke pumps. And Lonnie we thank you for posting video.

NOTE: If you find water in your Sea Doo pump oil? That means you have a bad pump seal and that the pump should be rebuilt with one of our jet pump rebuild kits 

By Robert Boop

When the weather outside gets chilly, it's important to take proper care of your watercraft to make sure it is in shape for when the water gets warmer and it's time to ride the waves again.
Winterizing your PWC will help protect it against the off-season elements during storage and get you on the water sooner when the riding season starts.
If you don't take your Jet Ski, Sea Doo or Waverunner into a professional shop for winterization, here are a few tips on how you can do it yourself and save a little money in the process. (Be sure to read your owner's manual and all product instructions for proper safety and maintenance information.)
Drain the engine
Get ready to store your personal watercraft for the off-season months right after you take your final ride of the season.
The first thing you'll want to do when you take your PWC out of the water is drain the water from the engine. The best place to do this is right at the loading dock when the craft is out of the water and the trailer is tilted so the stern is lower than the bow.
Start the engine a few times letting it run for no more than 30 seconds to prevent the engine from overheating. While the engine is running, turn the handle back and forth. This drains any excess water out of the engine.
Clean It Up
Take extra care to thoroughly clean your PWC one last time.
Wash down the exterior of the craft using the same kind of soap that you would use to wash your car. It might take some extra elbow grease to remove all the build-up, but removing the algae and grime now will be much easier than trying to clean it off after the storing period.
When you're finished cleaning make sure there is no water in the hull, and the interior and exterior of the watercraft are completely dry.
For extra protection on the exterior, finish your wash with a wax job and use a light coat of multi-purpose lube to coat any metal surfaces such as latches and hooks.
Gas It Up
Fill up the gas tank to prevent condensation over the storing period.
Top off the fuel tank with the appropriate amount of gas stabilizer, according to the instructions on the container. Using stabilizer prevents the gas from getting gummy, which can eventually clog the carburetors and make for a messy problem.
Start up the engine a few times for no more than 30 seconds. This not only allows the stabilizer to work its way through the engine and the carburetors but will drain any excess water out of the engine as well.
Remember to be cautious of where you store the PWC with a full gas tank since gas is extremely flammable. Storage near any heat source or source of sparks is very dangerous.
Oil It
The next step is to spray fogging oil through the carburetors and spark plug cylinders.
Begin by removing the air cleaners. This will allow you to spray the oil directly into the carburetor throat.
Start the engine and spray the fogging oil into the throat of both carburetors while it is idling. Continue spraying until the engine stalls and then replace the air cleaners.
Next remove the spark plugs, making sure the wires are grounded, and spray fogging oil into each hole for a couple seconds.
Place a rag over the holes and push the start button of the craft. This will not start the engine but will allow the oil to coat and disperse internally. Clean any oil that may have dripped and then reinstall the spark plugs.
Remove the battery
Check your battery and battery chargers for specific safety instructions.
Remove the battery by first disconnecting the negative terminal followed by the positive terminal.
Store the battery indoors in a warm place such as a shed or garage. We do not recommend storing the battery in your house, as it can give off dangerous fumes.
If the battery case is older, place the battery on a rubber mat for storage. Placing an older battery on concrete may cause the battery to conduct a current and eventually discharge it.
Attach the battery to a trickle charger and remember to check the battery water level every month throughout the storage period.
Storage
Because your craft will have a full tank of gas, remember to be cautious about the location that it will rest.
Put your trailer in a level position in the place where you intend to store the craft. The best way to prevent flat or corrupted trailer tires over the storing season is to take the tires off, store them indoors and use concrete blocks or a jack to hold the trailer in position.
If you choose to leave the tires on, cover them with tarps or durable plastic bags. To prevent rotting, place boards under the tires if the ground is gravel or dirt. Once the trailer is in place, unlatch the seat of the PWC to allow air to circulate through and prevent any moisture from being trapped inside.
Place steel wool or a rag inside the exhaust to prevent any animals or bugs from nesting there.
Finally, place your cover over your PWC to keep it clean and protected while it's being stored.
If you follow these simple winterizing instruction you will have a longer lasting life of your Jet Ski, Sea Doo or Waverunner.

By Bobby Boop

START EARLY: It's a good idea to get your Jet ski out of storage a little early and start it up. If you're taking it to a Jet Ski dealer to be summarized or get some PWC repairs, try to do it before the summer, when watercraft dealers tend to get overwhelmed.
WARM UP: Coax your PWC out of hibernation. If you stored your Jet Ski with some fuel in the tank and did not use a fuel stabilizer, condition the fuel by adding a conditioner Fuel System Cleaner and Stabilizer or drain out old gas (that's what I do). However, if you experience a no start and the fuel seems stale, then take your pwc to a qualified Jet Ski technician where trained Sea Doo mechanics are equipped to drain and dispose of fuel.
MAINTAIN LUBRICATION'S:  If you own a 4 Stroke engine, and didn't do it last fall, now's a good time to change the engine oil and oil filter, and drain and replace pump oil. You will also want to add grease to all grease fittings to keep bearings and seals lubed. For those of you who own 2 strokes, top off the oil reserve with fresh two-cycle oil, then drain and replace pump oil. You would want to grease fittings too.
SECURE LOOSE ENDS: Check for loose wires. Check throttle and trim cables to make sure they work properly.
CHARGE YOUR BATTERY: Charge and reinstall the Jet Ski battery.
 
These tip will help you get a good start to keeping you Jet Skiing on the water and out of the shop.

If your Jet Ski, Sea Doo, Yamaha or Honda has a problem when you take off from a dead start (slipping)? Then you need to check the pump area to see if you have an obstruction. First look through the exit nozzle with a flash light. If you see rocks or debris in the pump veins. Odds are that is the problem. You also want to look at the back of the impeller blades to see if they are damaged/dinged. If you see dings or it looks damaged the odds are you need a new impeller and possibly a new wear ring. If you don't see anything from the back, then look from the front of pump to see if you have any rope, string or weeds attached to the shaft in front of impeller.

If your impeller is old and worn out? this would also create a slipping feeling when you take off.
Impellers For Kawasaki Sea Doo Yamaha Honda