Pump ​impeller fail can happen in a couple of ways. 1st would be from wear & tear. The 2nd is from damage to the impeller & wear ring  from objects and debris being sucked up into the jet pump system. 3rd reason to switch out your stock impeller is for better performance out of your PWC or boat. Replacing stock impellers to get the maximum power from your jet ski or boat especially for watercraft racers is a plus.

​Do you have power loss/ performance loss? Are you having cavitation issue?
Look from the back of your ski or boat forward through exit nozzle and if you see dings are on your impeller? If So, Then that blade could be knocked out of degree and it is probably best you switch it out. 

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Impellers.com

I'm a little confused about whats right. This fall when weather started to get cold here I decided ( as I have done with my previous boats) to winterize my kawasaki jet ski. While I was searching for the best price around town I was surprised to learn that unlike boats different dealers have completely different ways of dealing with the cold. One dealer that all they've been doing throughout the years is running the motors dry until all the water is expelled. The next dealer said that I should take some part of the plumbing off and blow pressurized water through what I presume are the lines. And the last dealer said that I should run antifreeze through seawater lines to get the water out. Of course all of them Fogged the engines. What do you think is right? are all the methods okay?
Thanks Bobby

Dear Bobby,
In the cold you want to get out all the water as it can freeze and expand and possibly crack your cylinders and exhaust manifold. You want to run Jet Ski engine as it will get water out of exhaust system. You can blow compressed air through the water line that goes to the jet pump (blow air both ways). Or you can add antifreeze to the cooling lines filling up the waterjackets. Also add some fuel stabilizer to the fuel or plan on draining the gas before you go riding again and add fresh gas (You can take the old fuel and put it your car). You should add an ounce of oil in each cylinder, Charge the battery from time to time during winter.
Jetski Guru

I have a Yamaha GP 1200 and A Yamaha Waveriader 700. Both of these Jetskis had their Yamaha impellers freeze up in the Yamaha jet pump housing. My mechanic said this was the result of salt ( I run these PWC's in salt water) getting behind the impeller housing and causing expansion of housings into impellers. The JetSki mechanic suggested that I hose off the impeller and housing after each use. The Yamaha GP1200 has a Solaris SS impeller while the 700 is stock. Thanks for your assistance.
Buck

Hi Buck, Your mechanic is right and you should wash off salt every time you ride Jetski watercraft in ocean. It will help preserve your jet ski and its jet ski parts. The Yamaha Jet pump housing has this issue of becoming out of round due to a chemical reaction behind the Yamaha wear ring. We offer a solid steel Yamaha pump housing that will solve this problem.
​Watercraft Mechanic PRO

I have 2 1998 Kawasaki ZXI 1100's machines and they are both hard starting unless i pull the spark plugs and put a little gas into cylinder. If I do this they start right up. Can I put an inline gas bulb into the gas line and force gasoline into the cylinders before I try and start them?
Thanks, Mitch

Hi Mitch,
Yes, but we call it a primer kit. These primer kit will allow you to squirt gas into carbs with a push pull plunger that hooks up to the fuel line. Not only does the jet ski primer kit help with starting it also adds life to your Jet Ski starter.
Watercraft Maintenance Man

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 2001 Yamaha XL800, It runs great with one exception. after riding approximately 20-30 minutes or longer, If I stop 20-30 minutes or longer, it will not just crank up and go. If Im lucky , I can feather the throttle and it will clear up and go. One dealer says its a vapor lock caused by heat escaping via the carburetor. Another dealer says its because the engine cools off so fast that I need to choke it when restarting it. Chocking doesn't solve the problem. Once it gets going again, it runs fine. What do you think.
Steven

Steven, It sounds like you have a bad needle and seat in the carburetor. When you sit for 30 minutes the seat leaks and can flood your engine and makes it hard to start.  Get a carburetor rebuild kit.

I have a 1999 Sea-Doo GTI and I don't use the boat very much and it still runs well, but I am concerned about the pump carburetor failing from age and or wear. do you think the carburetor should be rebuilt at some specific interval?
Cory

Hey Cory,
  If the carburetor hasn't been rebuilt since 1999 then its time to rebuild carburetors. I like to rebuild my carbs every two years.
​Doo Tech Talk

I have 2 1999 Yamaha GP800's- One starts fine, the other will not start until you put starting fluid in the carburetor. It sounds like it is out of gas. Once started it runs fine, until it sits for 2 two or three hours, then it will not start. Put starting fluid in, starts right up. Been to the dealer twice with no help.
Kev

Kev,
  You could have a air leak in the fuel system.. Check all the fuel line fittings for leaks. Also, check your check-valves to make sure they are good. They should only blow one way. Also check your gas cap for missing o-ring & that it is not cracked. I would recommend installing a primer kit. It is better for your engine using starting fluid.
Tech Talk

I have 2 identical 1994 SEA-DOO SPX's. I ran them for a week at lake of the Ozarks in Missouri. They both ran generally great, however one of them experienced an issue twice during that time. . All of a sudden the one would cut out at full throttle. After sitting for the day it ran fine again. If I let off the throttle it would keep running. If I kept the throttle wide open it would die.
   It would always start an idle fine. It acted like it just couldn't get any gas at times. If I would "pump the finger throttle"  when this was happening, I could get it to get some gas and pick back up.  I got gas from the same marina all week. I check the fuel filter and it seemed pretty clean to me. There was a small amount of black grime or sludge in the bottom fuel filter, but not much. When it was having this problem, It would only go 3-5 seconds at full throttle before it would bog down. I am not a jet ski mechanic by any stretch of the imagination, however I am pretty handy and would love to learn to fix some of these problems as the arise.
SJ

Hi SJ,
 The symptoms you describe sounds like it is in the carburetors. because of the age of the Sea Doo , I would recommend a carburetor rebuild and flush the fuel system plus check the check valves that are coming off the fuel tank.
DOO Tech Talk

I have a 1998 Yamaha XL1200 Wave Runner. It is stock.  I am unable to start unless loosen the gas cap and allow the pressure to out of gas tank. This pressure/vacuum problem exists mostly when the gas tank is full. After loosening the gas cap it is still hard to start. Once started and run,  it will restart for the rest of the day. Would I benefit  from installing a primer kit on the three carburetors? Would I have to remove the choke plates in the carburetors if I were to install the primer kit?
Pedro

Hi Pedro,
 On the Yamaha XL 1200, the fuel problem you have can be with the check valves or a restriction. But first you should fix the choke or install a primer kit if the choke can not be adjusted to close all the way. They must close all the way to work.
PWC Tech Talk