Rotax 500, 600, 700, 800 Top End Installation
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- čas přidán 31. 12. 2020
- This is the installation of a top end on the x93 series Rotax twin in Ski Doo snowmobiles. The head on the 793(800) is slightly different but specs and patterns are the same. I also discuss and explain base gasket thickness and its effects.
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I always bolt the exhaust manigold to the cylinders and intall them as a pair. It keeps them true to each other. Also the base gasket should have a thin film of anerobic gasket sealer on both sides to alleviate the coolant eventually deterating the paper gasket. This is per Bombardier service manual. I was a service tech for Skidoo for 42 yrs......got in on the 2001 piston recall ,where I rebuilt 40-50 of these during that snow season in Montana.
Thanks!
Hey man, what’s the best way to get the bass gasket residue off without scratching the surface?
So many people on the forums don’t any sealant on the gasket. Many of them swear they install them dry and they last a long time. Not sure if it’s true or not.
Maybe you can help identify my engine I know it's a rotax 700cc 2 cylinder stroke but that's about it I'm sure it came off of a snowmobile but it is on a drakart now but to find parts and specs would be easier if I knew what it was on I'm thinking mxz formula 700
excellent video,great explanation of base gasket effecting the port timing !
*affecting
You make that cylinder installation look so easy, I'm not sure why I'm having trouble getting the cylinder to slide past the first ring.
Piston rings upside-down?
I always use Wiseco circlips I can actually push them in with my fingers without the need of a flat head screwdriver ! They are the easiest ones to push in !
Would this be the same as the 87 ski doo 503? I Have an old stratos thats only got 65 psi in the cylinders. Runs but wont move.
Just got my bass gasket and my old one did not have holes in the middle
This new base gasket has 8 holes
Does that matter ?
It’s a double gasket 0.8 mm
Put red locktite on the exhaust bolts...the bottom ones are a bit of a pain to get at if they fall out
Thanks for the video Mac, I learned a lot. Do you know if this engine has the nikasil coating in the cylinders or a good old fashioned cast iron sleeve? I have a 2002 Rotax 600 which I am guessing would be the same as yours and need to do a top end and possibly some cylinder work. Thanks, Jon
I can tell you for sure the 500 is an iron bore, honed mine in the shop. From what I can tell 600ho is nikasil the non ho 600 is not.
@@macsgarage I'm glad to hear that, thanks Mac!
I have one of the engines on my drakart it runs good but im sure its ready for a new top end any suggestions on a place to get the parts ?
Would the process in this video be the same process when i rebuild my 2008 Ski-doo Summit X 800R 154" RevXp? Or is it different?
If it has 793 on the tag mounted to the mag side of the engine it should be the same. I don't have a manual for an 08 at this time so I can't really verify. Should be pretty similar though
The oiled assembly has been replaced by dry assembly mostly these days. There will be oil coming with the gas.
Anything that moves on startup needs oil immediately. Oil is coming eventually but it should be there right away. It should be a conventional 2 stroke oil though.
They all had cageless needle brgs. when I did them!
I’ve replace this cylinder base gasket 2 times now and still wants to seep out? I’ve tighten in a kris cross patter at 21foot pound
Many of the shop manuals show cyl torque at 21..where if you check service bulletin or the dooforum you will find it is actually 30ftlbs.
Head is 21.
What year is your motor? I have a 600 ho swap in my 800 but don’t know what year it is and I need a cylinder
This one is a 2001. You should be able to use the casting numbers to make sure you get the correct cylinder.
Looks like a top end rebuild kit for my machine, the pistons are available in three different sizes. How do I choose? Thanks!
You will need to measure your current pistons or look for markings on the top. If the cylinders need bore or hone work you could have the person doing that measure and advise.
@@macsgarage Got it, thank you!
so do you not use the loctite gasket maker on them?
I did not. Skidoo specs an anaerobic sealant and you probably should use it. However it hasn't been an issue on mine yet.
maybe its just me but my hands are covered in new 2 stroke oil (klotz cuz it smells good) when installing new pistons.. that pin going in dry makes me cringe
i got a quick question for you Mac. Just got finished rebuilding the top end on my 2001 mxz 700 deglazed and freshened up the cylinders new pistons, rings and gasket kit. they are single ring pistons and my question is is there a top and bottom to the rings? i tried to start it and felt like no compression tore it back down and both rings are stuck in the ring lands im stumped. cylinders and pistons seem to be okay.
If there is a marking on the ring it should face up
thanks so much for your reply mac! i checked my old pistons too and the markings face up. im going to flip the rings and try again cheers!@@macsgarage
One other question for you if you don’t mind. I have a 2001 mxz 700 with a mangled pilot jet. Can I use 2002 mxz 800 carbs on my 700 if I swap the main jets and the needles from the 700 to the 800 carbs. I have both sets at my disposal.
@@beerman2for1 I don't know that one off the top of my head. I'd check part numbers between the two.
They are both 40mm carbs. The part numbers for the carbs themselves complete are different. However, all interchangeable parts excluding main jets and needles are the same from 2001-2002. I’m going to build a set with my main jets and needles and I’ll let you know how it turns out 👍 thanks for the reply. Love your videos
Usually I never took the exhaust manifold off
Это 493?
Where do u buy the kit from?
eBay has them for $200
how do you add oil to crank case?
The only oil in the crank case is in the center. It's not something that gets changed like a four stroke. If the sled has an oil injection tank there is a line the allows oil to flow into the cavity when the tank is totally filled with oil. If it's a premix engine there should be a small bottle that gets filled with oil to keep that area lubed
I was really hoping there would be some information about putting the stator in properly I have no idea how and that is the thing I am most worried about. Anywhere you know that can help?
Sorry I missed this when you posted it. I'll probably do something with the stator later.
Do you need the torque specs?
@@macsgarage at least where you got them from would be nice maybe you said all that I need to know
Kind a pistons you use?
Pretty sure those are spi.
@@macsgarage thats what i have in my 700 so far so good.