Rotax/RAVE Exhaust

[spanky]

I was gonna try to clean my power valves today for the first time since I've owned the sled. I pulled the black and red covers off, caught the spring, and that was it. I got to the round green/tan thingy wrapped with the spring and it was free and moved fairly easy, but wouldn't come out. I took out the two socket head srews but nothing came out. Does the valve pull out so I can get the crud out of there? It felt like it didn't wanna come out. It's new to me to have this set up so any pointers would be great. Also, is it better to use synthetic oil, if so, which brand?

[revrider19]

they wont come out because they are carboned up . otherwise they will pull right out when clean . you may have to lift the power valve up just enough to get some pb blaster in there . slowly push and pull valve till free. my skidoo rave valves took awhile but i did get it . my arctic zr valves are even worse to free up .
unless you use oem specified oil to keep the power valves clean youll have to clean them more . i use amsoil . but everyone has there own opinion .

[spanky]

OK, so what about the smut that I can see around the valve hole, can that crap go into the cylinder?? If and when I get the valves out and cleaned, do they need to be lubed with anything or will the exhaust do that naturally while it runs? What is PB blaster and where can I get it?

[2doo]

If you put the piston all the way up on the side you are working on, it shouldn't get into the cylinder. The pb blaster is a glorified wd-40. As far as oil goes, I use amsoil interceptor and have yet to have exhaust valves hang up in 4700 mi.

[revrider19]

i use a little bit of the 2 cycle oil and just lightly coat them . i am with previous post of just putting the piston up . good luck ! on my zr they were so bad i had to pry them out i had no choice so hopfully you dont have to . please repost when ya get them .

[spanky]

So, all I need to do is pull the plastic covers off, and then the pistons should come out? I don't need to take the other 2 bolts out? i'll give it a whirl again and see what happens. THANKS

[1fastmxz]

Yes, you need to take the plastic cover off to get to the two mounting bolts. you'll need metric allen wrenches to get the mounting bolts out. you maybe having trouble getting your valves out if the gaskets are holding them in. also make sure you don't install them upside down when reinstalling them.
If your still having problems let me know and I will go pull mine and take step by step pictures for you.

[spanky]

Actually i had the two mounting bolts out for one of the valves, I just couldn't get the piston itself out. The gasket was in good shape and also came off with no problem. I was concerned with the smut that I could see around the hole for the piston. And I didn't think I should pull on something that I didn't realy understand. So what you're saying is the piston "should" just pull out of there? How necessary is this task? I can fudge my way thru most of the other stuff on the sled, but when it comes to motor stuff, not so much. I'd rather sound like a dummy and ask questions. Too big of an investment to dink with!

[1fastmxz]

Spanky,
Just like riding a bike after you've done it once it's a piece of cake.
if your valves are that gummed up it's time to clean them. like stated before pull plug and make sure piston is up. the valves are actually flat plates, (guillotines ) you might have to work them in and out a bit to get them to come out. there pretty sturdy if your pulling straight you'll be fine.

[revrider19]

yes they should just " pull " right out ! with no effort . its certain they need to be cleaned and all that carbon junk your seeing is the reason they wont . take your time do it right and next time youll see how easy it should be . btw i clean mine before i put it away each year just so i know i will not have issuse's during the season .

[spanky]

Thanks guys! :D I'll make the time to get it done

[spanky]

Thanks again for the pointers on the RAVE cleaning. I got it done today without any trouble. Took about an hour I guess. Nasty in there though, solid black carbon!!!! So, now that they're clean, what kind of performance changes can I expect?

[revrider19]

just a thought but it will run better ! but more on my thought ! i turned out the red dial in the middle of the valve housing . about 7 clicks . which allows the valve to open a little fast due to less spring pressure . i am assuming yours is in the stuck position ? when i did turn it out the red dial was about flush with th black housing . has more top end and midrange . dont go to far youll lose som bottom end due to the valve opening to fast .
let me know what you think .
p.s i am glad you got it !