Cleraning Pistons

Note: This site contains eBay affiliate links for which may be compensated
Not open for further replies.


New Member
I recently got some advice from a local mechanic and I just wanted to pass it along to ya'll and see if it was good/sound advice before I attempt it on my own ski...

First off I have a Seadoo 97 GTS with a 717 engine... and I have noticed as of recently that the engine is not preforming as well as it used to until it gets warmed up...

He suggested that my sluggish problems that I have been having is because of carbon build up on my piston and piston walls... he said for me to take to plugs out and spray break cleaner onto the top of the pistons and then turn the motor over and then repeat and then spray pretty liberally again... then take a rag and place it over the plug holes and press and hold the start button for about 5 sec... and then check the rag for dirt and grim... then he said for me to repeat the process until the rag is clean afterward...

He also stated that I need to be running 93 unleaded gas in my seadoo...

Please reply with any suggestion that this is a good idea or maybe any other suggestion that you might have to clean the engine...

I wouldn't use the brake clean.. If you want to clean the pistons and walls id pull the head off and use some mineral spirits because the mineral spirits wont affect seals and gaskets brake clean might eat seals. I use mineral spirits when i cleaned my motor and crank when I took it apart and put it together. I used it even leaving the crank rotary seals still on and no problems.

The sluggish sounds like carb problems.
So... once you clear all the oil out of your engine, and causes a bearing to fail... or the break cleaner eats the center seals from the engine... is that mechanic going to pay for the rebuild??

That has to be the worst advice I've ever heard.

OK... will it clean the pistons??? sure it will, but it will cause more damage than it will help.

As said above, if you feel that you need to clean the pistons... pop the head shell off, and clean them manually, and DO NOT get any solvent down in the crankcase.

With all that said, if you are loosing perfomance... check the compression. If it's low, do a top end rebuild before you have an engine failure. (it's cheaper to replace parts while the engine is still runnable) If the compression is still good, then figure out why you have lost performance.

Last thought... if your engine is running properly, and you are using an approved oil, there should never be a reason to need to clean the carbon from the piston.
Last edited by a moderator:
Thanks Tony for the advise...
and I doubt that he would pay to rebuild anything... I just know that he claims to have been doing this on boats and skis all through out his carrer...

Here's some advice for everyone reading this.

There is no easy solution for a mechanical problem. There isn't any miracle pour in, or spry on solution to a problem. If there is a real problem, things need to be disassembled, cleaned/rebuilt, and then reassembled.

This isn't a flame or a bashing... but at least once a week, I see guys saying they poured something into their fuel... or sprayed something into their carbs, and the ski still won't run.

One last thing to think about.... If a chemical is harsh enough to dissolve a problem (carbon deposits, varnish, gum) what do you think it's doing to that little bit of oil that is being transported by your fuel, to lube the engine?

On a 4-stroke, if you want to put a little carb or fuel injector cleaner in the fuel... go right ahead. But on a 2-stroke... it's a very bad idea. (it could cost you your engine)
Not open for further replies.