1998 XL1200 Cavitation

[Alabamarebel]

Hello Guys
I need a little advice.I bought this waverunner new and have lost about 7-8 mph over the years.Before last summer I pulled the top off the engine,replaced the rings,did a mild port and polish on the intake and exhaust side,removed the chokes and installed a primer kit.It did not help the mph at all.So we rode it all last summer and this summer up untill now.I have noticed for the last month it will not take off like it suppose to.When you hit it full throttle from a stand still or about 10 mph it revs wide open untill it gets to about 20 mph before it will grab and then its gone.It acks like a stick in the impeller.Today I removed the pump housing and impeller.impeller looks like new but the housing around it has a few scars and ridges in it.Is it possible this is causing the cavitation and the loss in MPH I am expercing.There is a good bit of alge and crust inside the pump and on the grate.Does the pump housing have to be replaced or can the wear ring be removed and replaced...Thanks for your help and looks like I have found a good place to hang out........AR

[Alabamarebel]

Re: 1998 XL1200 Cavitation

Wow
I thought maybe there would be at least one person that would help with my problem..The local dealer thinks you owe them something and they wont help either unless you take it to them and spend a fortune.i can put it back together and ride it another season...Thanks everyone...

[Alabamarebel]

Re: 1998 XL1200 Cavitation

Well can someone point me to a link with all the pump specs so i can mic everything .I have searched the web with no luck.Does anyone have the ride plate mod instructions for more top speed.i found the mod to cut the two center bars out of the grate to improve water flow..

[bob1100]

Re: 1998 XL1200 Cavitation

Pretty much the same here posted about a problem days ago, no help. I wonder how good the replys are when you buy a top end kit form SBT? I smoked the # 3 cylinder and really would like to talk about the rebuild and the parts .

[John Kubiak]

Re: 1998 XL1200 Cavitation

try www. pwctoday.com ...this site is specifically for SBT related issues...SBT is the sponsor of this site and pwctoday.com!

PWCToday
ALL non-SBT discussion goes here - this takes you to the new Forums for all Brands, classifieds, etc.

[mortimor]

Re: 1998 XL1200 Cavitation

Ive been pulling my hair out all summer troubleshooting a cavitation problem too. Also a xlt 1200. ok through much research and talking with yamaha dealer tech's numerous times, my problem was due to 2 small dings on the impeller...I refused to believe it for months....I replaced the impeller and now runs like new..I would have never guess that it was actually the problem....
Due to the XLT 1200 being one of the heaviest waverunners made, the pumps works extremely hard on these. Anything as small as: gouges in your pump housing, or just a bit too much clearance between impeller and the housing, or like mine just dings on the inner edge of one blade, any of these will cause cavitation... (mine cavitated only at 15mph and 5k rpm) ...hope this helps.
Dont rule out dents, dings as potential problems here...
If all is good in there, pull the carbs off and give them a good cleaning or rebuild if its time..

[Madfish]

Re: 1998 XL1200 Cavitation

First of all, anytime you plan on working on your own ski, the first thing you need to get is a service manual. They can be really helpful.

I had this same cavitation problem with a 1999 XL1200 Ltd. The problem was a rubber seal under the ski in the pump area. The seal is about 8 inches long, 1 1/2 inches wide, and 3/16 of an inch thick. The seal is under the intake duct where it bolts up to the hull. If this seal gets wrinkled or blown out you ski will act like its in neutral or act like a slipping clutch in a car.

[Alabamarebel]

Re: 1998 XL1200 Cavitation

Thanks Mortimor and Madfish
I put it back together yesterday but havent had time to try it out.There was a small ding in one of the vanes which I took my die grinder and resharpened.I also debured any small burs on the impeller.I polished everything inside the intake and outlet,I then sprayed a coat of molly on everything inside the intake ,impeller and housing and the outlet.It is very slick now and says it can withstand a thousand lbs.pressure so I think it will stay on.I also put a bead of silicone on all the seals your talking about so it should be sealed up tight.And as far as this being a SBT site,I purchased my parts from them when I did the rering job.I just hoped they would be more helpful than the local dealers are. Thanks again Guys