Tech Q & A

Q. Does Impros balance each impeller they service?
A. Yes. Each and every impeller that we service is checked for accurate balance within 2/10ths of a gram. Slight rock damage and especially with impellers requiring weld, checking the balance is absolutely required with PWC impellers. Sometimes we’ll find new impellers out of balance right out of the box. We balance each impeller as the finish is applied, eliminating any chance of throwing it out of balance during the polishing process. These measures are proudly taken to insure our customers the highest quality impeller repair available. Ask our competition if and how they balance impellers, we’ve found that they typically rely on the original factory balance.
Return to Top

Q. My bearings went out in my pump, can Impros fix my impeller so that it fits tight in the pump like it did when it was new?
A. In most cases, yes. We are a full-service impeller repair facility, which enables us to weld the outside diameter of the impeller, cut it to the correct diameter to fit the pump, machine the excess material, re-finish it and re-balance it. Most other repair shops do not offer a complete rebuild, usually because they are not capable of balancing the impeller after adding material, another reason to trust Impros for all of your impeller needs. These measures are proudly taken to insure our customers the highest quality impeller repair available. In cases where the diameter is worn beyond repair, it is usually less expensive to purchase a new impeller rather than incurring additional costs to save the damaged one. Impros also offers used, reconditioned imellers for many watercraft.
Return to Top

Q. Does the number that my impeller is labeled mean that is literally the pitch of my impeller?
A. Not exactly. The numbers refer to the outer blade angle of each impeller blade. Although commonly used in this industry, the word pitch does not apply to a PWC impeller the way it does a boat propeller. Where the pitch on a boat prop refers to the distance the unit moves forward per revolution, PWC impellers use numbers that reflect the outer blade angle, which identify how aggressive the impeller is, and also as stated in the question is a “label” to distinct between other labeled impellers for ease in applying each impeller to a particular watercraft. The number of that angle cannot always be taken literally, because all of the impeller manufacture’s today have been known to slightly change an angle or length of the blade to optimize performance, and not change the ID of the impeller because the label of that impeller is already known to perform with certain characteristics on certain watercraft. This is one of the most important reasons that you will benefit by purchasing your impeller from us, and sending your damaged impeller to Impros for service, we understand the differences between each manufacture, and assure the pitch to returned to factory specs- not to that of some type of angle device or boat prop gauge.
Return to Top

Q. Does Impros use correct pitching techniques specific to each brand of impeller?
A. Yes, Impros is proud of our ability to pitch each brand impeller to the manufacture’s specific range of blade angle variation. Impros has a master gauge for every stainless-steel impeller made, assuring an accurate pitch and uncompromised performance, eliminating common guesswork. Each and every manufacturer builds the impeller geometrically different from one another and gauges the outer blade angle in a different way. Only a company with experience will accurately understand, manipulate and repair the blades of the impeller to its original state. 
Return to Top

Q. Does making a few modifications to my PWC like changing the pipe or raising the compression mean that I have to purchase a brand new impeller with a different pitch?
A. Not usually. People commonly feel that they need to purchase another impeller with every modification made to the motor. This is usually not the case, however sometimes you can squeeze a little more performance out of your craft by having Impros change the pitch of your existing impeller to maximize performance. Our impeller recommendation charts will give you a very good idea of the type and pitch impeller that works best on each watercraft. Owners of watercraft need to remember that a higher pitch does not always mean more speed, motors have a range that peak horsepower is produced, and the impeller can limit or allow the RPM’s to reach a certain level. 
Return to Top

Q. Does the combined weight of me and my passenger(s) make a difference on which impeller pitch I should use?
A. Sometimes. The original impeller is designed for good general performance, but every riding situation is different. Sometimes people will drop down a step-in pitch to maximize the acceleration of the watercraft when normally carrying heavy loads, or in another case, a single rider on a craft intended for towing or multiple passengers may want to have us raise the pitch of the stock impeller slightly to increase performance of the craft. Read more about this subject in the “Impeller Basics’ section located at Impeller Basics.
Return to Top

Q. How do I know if I should change the impeller on my craft to a performance type impeller?
A. This needs to be answered case by case, but the fact is, most of the later models of watercraft are coming straight from the factory with excellent impellers in them. They have either borrowed the latest design characteristics from the aftermarket companies or are having companies like Skat-Trak or Solas manufacture them for them with their very same designs. When there is an impeller available that is promised to gain performance, it is usually miniscule, and we can usually get the very same type of gain by re-pitching the existing impeller. 
Return to Top

Q. What’s the difference between a polished finish like Solas provides and a textured finish the way Skat-Trak does it?
A. We have not found any performance gains by polishing impellers. Some people prefer the cosmetic appearance of the Solas, and some like the ground finish that Skat-Trak performs. We have found the finish that the O.E M. companies use in the latest high-performance craft to work exceptionally well compared to a high polished look. Most professional engine builders/tuners prefer a textured finish on the impeller, with the pump being as smooth as possible. Since we have not found any performance gains one way or the other, our recreational finish used on our repairs provide exceptional performance. Each of our “Power-Tune” impellers are returned with our recreational finish unless you’d prefer our race finish as an option because we balance the impeller to a higher degree as the finish is applied, eliminating any chance of throwing it out of balance during the polishing process. 
Return to Top

Q. Will I save money having my impeller repaired or modified, compared to buying a new impeller for my craft?
A. Absolutely! The cost to have Impros repair or custom pitch an impeller ranges from $65.00+, while an aftermarket impeller for most late model watercraft typically range anywhere from $175.00+. 
Return to Top

Q. Does the pitch of one brand’s impeller compare in performance to a different brand’s impeller with the same pitch?
A. No, unfortunately it is not as easy to compare impellers on watercraft as other types of drivetrain like typical gearing on other types of vehicles. Each of the impeller manufacturers today (including the original impellers on current PWC) measure the blade sweep in a different way. Which means the percentage or amount of blade length per angle of progression varies from impeller model to impeller model. There are also many geometric differences between the different brands and models of impellers, for example- blade length, hub size, root angle, and position of the impeller in the pump. These and many other factors are at least as critical as blade pitch, and all have a large effect on the load and efficiency within the pump.
Return to Top

Q. Can Impros modify my stock impeller to increase the performance of my craft?
A. Usually. The original impeller is designed for good general performance on that particular craft in stock form, but every rider’s performance desire and riding situation is different. Sometimes people will drop down a step-in pitch to maximize the acceleration of the watercraft when normally carrying heavy loads, or in another case, a single rider on a craft intended for towing or multiple passengers may want to have us raise the pitch of the stock impeller slightly to increase performance of that craft. Also, when you add modifications that increase the power of the engine, we can make the impeller more aggressive to more closely match the added horsepower. High altitude is another concern, Read more about this subject in our
“Impeller Basics” section located on the Technical info page.
Return to Top

Q. Is my impeller going to be as durable after being repaired?
A. Yes, the process does not stress or weaken the impeller in any way, however in a case where a particular impeller has been repaired several times, eventually the blade thickness may become thin and weaken them.
Return to Top

Q. Can Impros turn my straight pitch impeller into a progressive pitch?
A. Yes, but as with all re-pitching, it depends on what you’re starting with, and where you want to go in pitch. Please be aware that we have to take other geometric traits of each impeller into consideration like the blade’s root angle, so if for example, we pitched a 15-degree straight pitch impeller to a 9/17, it may not perform exactly like an original 9/17, but will be close. We recommend that you email us or call and discuss the situation with a tech prior to sending the impeller in. 
Return to Top

Q. Can Impros turn my conventional style impeller into a Swirl or Concord?
A. No, some people cut the leading edges of various conventional style impellers giving them a radial “Swirl” look to them, but the design differences that make a Swirl or Concord work the way they do runs far deeper than a radial edge of the blades. Although sometimes, when we modify an existing impeller for specific applications, which requires an alteration of the blade. 
Return to Top

Q. How do I change the impeller in my craft?
A. Impros has complete impeller installation instructions for Yamaha, Sea-Doo, Kawasaki and Polaris PWC located at Impeller Installation instructions for the person that likes to get in there and do things themselves.
Return to Top

Q. I bought an impeller that is too aggressive for my application, can Impros help?
A. Yes, Impros can reduce the pitch of the impeller, which will limit the amount of volume passing through the pump, therefore making it easier for the motor to rev to the ideal range. Unfortunately, in some cases, a person may have an impeller that is drastically incorrect for the application, and we may be limited on the amount of pitch we can change it, but it will still provide a positive gain. Contact us beforehand, so we may advise you of all your options. 
Return to Top

Q. I was very happy with the performance that the OEM impeller produced with my craft, do I need to replace my damaged impeller with an aftermarket type, or can my original impeller be repaired.
A. If you liked the performance that the original impeller provided, you will save money and retain the performance you were comfortable with by sending Impros the impeller for repair. The fact is most of the later models of watercraft are coming straight from the factory with excellent impellers in them. They have either borrowed the latest design characteristics from the aftermarket companies or are having companies like Skat-Trak or Solas manufacture them for them using their very same designs. The result of this is that usually, the aftermarket companies are unable to produce an impeller with very large gains at all. The O.E. impellers are also being made with higher quality stainless steel than they used to, making them as durable as the aftermarket brands available.
Return to Top

Q. If I buy an aftermarket performance impeller instead of having my original one repaired, will my watercraft gain top speed?
A. Not always. Some impellers are designed to increase top speed of the watercraft, some are designed to increase the acceleration, but usually the performance gains are minimal. We also provide perfomance modifications to impellers, and are able to more closely match an impeller with the engine mods.  It is always best to specify the type of performance increase that you are looking for when re-pitching an impeller, from there, we can discuss the options available. 
Return to Top

Q. If I install an aftermarket impeller on my watercraft, how much performance gain should I expect?
A. The increases an impeller will provide whether it is top speed or bottom end, vary with each application. Sometimes the manufacture can get a specific design impeller to produce 1-2 mph top speed with no other modifications, and sometimes they can only promise to retain the top speed with gains only in acceleration. Some impellers are designed specifically to reduce ET (an increase of bottom and mid-range power), which are very popular for closed course racing, and recreational riders interested in more acceleration or towing power. Also, when an impeller is developed that is more efficient than the original impeller, they offer a variety of pitches to accommodate the many different applications and variables that are usually present, like rider weight, altitude, motor modifications, and the rider’s performance desires. As stated in the question above, you might want to contact us and discuss modifying your existing impeller, chances are we can squeeze the performance out of it, for a lot less money.
Return to Top

Q. Will a Swirl or Concord type impeller make my watercraft go slower?
A. Not always. Like all other impeller designs, there is a specific pitch recommended for each watercraft, and by installing the wrong pitch on your PWC in an attempt to maximize performance gains, you can actually lose performance. In most cases, the Swirl/Concord design maximizes low to mid-range acceleration, while retaining top speed compared to the original impeller. This style is very desirable in closed course racing, or conditions where the water is usually rough. In some applications, we find top speed gains, and some losses as well. 
Return to Top