I just finished disassembling my 1993 MX 470 because the #2 piston was stuck. Using your video, I came to realize that the pistons were installed backwards by the previous owner and this caused the ring gaps to align with the exhaust port. The end result is a scored cylinder by a broken ring on #2. The #1 cylinder was also scored and the ring was already bent - caught it before it broke! Will be getting new pistons, rings and cylinders. Thanks again for the video!
awesome explaination man... this is my first time rebuilding a 717 rotax 2 stroke engine from my 1997 Seadoo GTS jetski and i didnt have much idea of how emsanbling everything... i got a manual, but i still need someone watching how they do it but thank much man ! good bless you for sharing your knowlegdes with the world !
@davison1021 Check the float and float needle in the carb. floats are getting stuck of the needle isn't sealing. It causes the bike to flood when you let it sit
@1skiinIan Hey there.I've rebuilt a couple of 521 rotax motor's.These are one amazing motor.I've got the manual for this motor.In the rebuilding section it say's a good rule of thumb for keeping you jug's straight is a feeler gauge inbetween the jug's both end's and centre when torking down the jug's to keep it as straight as possible.Just thought I'd throw that out there.Chee's Bud.
@BriZav squeeze the rings with one hand and lower the cylinder over the piston. Don't force anything. Make sure you line up the ring gaps with the ring stoppers
@117nathanmyers i don't know it seems pretty clear to me. you can see the pin in the center of the ring gaps where they have to be when you install the cylinder over the piston. That pin stops the ring gaps from moving to a place where when they are installed could potentially catch on one of the ports in the cylinder. It doesn't matter in a 4 stroke because there are no ports in the cylinders.
@KeepItRoostin658 make sure you tighten them all the same amount then, using a torque wrench, or if you are very experienced you can do a pretty good job at getting them all around the same tightness
@ballockybill they are power valves. dirt bikes have them too but they are internal. They are like sliding plates that close off the exhaust ports a bit and open at higher rpm so that you can still get good power and torque at lower rpm's without sacrificing high rpm power and torque. good question though thanks
@KeepItRoostin658 you keep doing it like that and you'll end up with a warped mating surface , every motor has been giving recommended tq specs by the factory usually a looser spec to seat the surface than the second spec to tighten the seal.
@danceGIRLIES101 It's very rare that the piston get damaged without damaging the cylinder as they are in full contact but, if so, you still need to measure the bore of the cylinder in at least 3 different spots to make sure it hasn't worn in a taper or too much in an oval before you figure out the size of piston you will need to order. if your standard piston has become too small you will need to have the cylinders bored and honed for the larger sized pistons. always hone
@KubotaTee Thank you for that post. this proves to @DangerZONEpixel that pistons have to be installed a certain way so that the ring gaps don't end at a port
@haloass123 yeah, in a 4 stroke they would be. in a 2 stroke you don't have a choice. you have to lign them up with the groove on the piston and install the piston the right way so that the ring gaps are in between the ports. Typically in a 4 stroke you want to have the ring gaps 120 degrees away from eachother. In this case, they are only about 90 degrees because they didn't have a choice because of where the ports were
@danceGIRLIES101 A lot of the newer 2 stroke motors can't be honed and therefore you must send them off to a machine shop to be re-plated or resleeved.
@MegaDanTheMan1987 you're going to have to take the jugs off to see if you have a crack anywhere. if there isn't it's probably the base gasket. replace it and reassemble
@kaseycoleman993 thanks for the explaination i already found it out myself, its just commen sence when a piston at the turning point to from up to down or down to up the g force will be extreem high on the clip i think it will never go wrong at a max 5000rpm engine it wouldt go wrong on a 8000 to 12000rpm engines what do you think!
@1skiinIan no its a yamaha dt i already did the top end the other day and it is actualy really simple i put a wiseco forged piston in as i didnt want to let it break in the first place
@1skiinIan yeah I stopped letting friends borrow my tools years ago . Every time I lent out a tool, it never returned, so I decided I cant be the local rent a center anymore lol.
@Maximusfool The head has been planed for higher compression. I have it tuned pretty well. It's bored .20 over, so maybe 5hp more than stock? so like 120? ish
Oh yea.... thats right.. I never take the manifold off... just the pipe!! Duh lol. Yea ours sucks cause we just have no snow all winter. barely 4 inches in some spots. Good video!
@LegittGod39 no, if it's oil injected, reattach the oil injection hose and loosen the bleed bolt untill oil starts coming out of it. after that, pull over the engine with the oil injection lever wide open untill you see oil coming out of the tiney holes in the bottom of the ports (this is with the carbs off of course). also, just to make sure I always mix oil into the first tank of gas on top of the oil injection. (mix at about 100:1)
not sure if it would apply here but many new rotax engines call for the head pipe to be installed befor the torquing of the cylinders to prevent leakage
Do you use gasket seal? and also, im doing a top end rebuild on my yz 85 dirtbike, would i HAVE to use a toque wrench, or would you say two fingers on a ring ended spanner would be ok?
@117nathanmyers The ring gaps should NEVER end in the same spot on the piston in any type of engine. This would result in a loss of compression. In most 2 strokes though, there is a tab where the ring gaps have to be so that they don't spin and catch a port.
hey if i have to crank my bike many times really quick to get it started with full throttle but once started i can start it no probe for like 24 hours and yesterday full of gas started coming out of the expansion chamber near th cylender? what would you say that is bad fuel mix or spark plug?
I noticed the base gasket moving around when installing the cylinder, shouldn't this have had gasket adhesive installed between crankcase and gasket? I'm asking because im getting ready to do my motor.
@outdoorsman310 no, there are groves made in the piston. This is what I am talking about in the video. you lign the ring gaps where the notches are on the piston. You also make sure once you put the piston in that the ring gaps don't end at any ports
@1skiinIan i have a problum i was opeing a techumas engine 2 stroke from a snowblower toke the connecting rod of the crankshaft but needle bearings fell all over the place and i dont know how to put them back cause theres no cage to hold then ? can u help me out please i dont know how to put them back on lol (they fall out) Thankz
hey, i have a question..... i have a 1997 ski-doo formula 583.. its leaking anti-freeze in between the right cylenderand the block.. what should i do to fix this?
@1skiinIan yea i noticed LOL but would u know how to put the bearings back on cause i wanna put it together cause its not mines LOL its my freinds Thankz
what happens if there stay a little piece of viber of that cloth in the engine or on the cilinder.I aint NO monteur but still tried to fix my bike after my engine filled up a little with water but cause i aint no expert i made a big fauld with making it dry and a little piece of cloth stayed stuck between the wholes and cilinder how you see it at 6:01min. It were some really small tinie vibers that stayed stuck but i think vibers went more into the engine and now i got BIG problem won't start :(
Let's say a piston gets damaged in a 2-stroke and you want to rebuild it, do you have to hone the cylinder if it looks good? Or can you just replace the pisons as the cylinder is?
@farisman09 Yea i think i might try the heavy grease cause i tryed looking around and like non of them seem to be the rite size cause techumseh fcked them up and also u cant even get parts for these motors can u suggest any heavy grease i might be able to use (one things for sure iam never ever gonna touch another techumseh engine in my life) LMFAOO if i cant get it with heavy grease i know were that engines comin ...... into the lake behind my house Thankz bro
@1skiinIan hey would u know why my 110cc atv wont start well i know that part lol theres no spark. but it cant be cdi cause it starts rarly like if i crank it for 5 mins it MIGHT start for 2-7 sec then off and wont start again.I cant get the vavle cover off to set the timin cause the screws are in a spot were its like impossible to work on this pieace of shit. would u know why iam not gettin spark all wires are good and gas is good but compression isnt that good but cant get to the vavle cover
@DangerZONEpixel "To prevent ring breakage, make sure all port edges are chamfered @ 30 angles with a radius of 0.9 to 1.4 mm" so suppliers are wrong in this statement?
I just finished disassembling my 1993 MX 470 because the #2 piston was stuck. Using your video, I came to realize that the pistons were installed backwards by the previous owner and this caused the ring gaps to align with the exhaust port. The end result is a scored cylinder by a broken ring on #2. The #1 cylinder was also scored and the ring was already bent - caught it before it broke! Will be getting new pistons, rings and cylinders. Thanks again for the video!
see this guy right here? this is a smart man that will do well in life. Thanks for watching!
extremely well done video, best engine rebuild video that i have found on youtube
Very helpfull video for all 2 stroke engines, it's basicly the same.
awesome explaination man... this is my first time rebuilding a 717 rotax 2 stroke engine from my 1997 Seadoo GTS jetski and i didnt have much idea of how emsanbling everything... i got a manual, but i still need someone watching how they do it but thank much man ! good bless you for sharing your knowlegdes with the world !
I'm in the process of rebuilding a El Tigre 6000, and Exciter 540.
Nice tips...
THAT'S HOW i learned to change my moped rings
@davison1021 Check the float and float needle in the carb. floats are getting stuck of the needle isn't sealing. It causes the bike to flood when you let it sit
@TaKeItLiKaMaN Correct! 1993 formula Mach 1 670
The purple heads are found on the 670HO (high output) engines that had a bit higher compression.
very nice vid man keep them vids a coming your good at rebuilding engines
@1skiinIan Hey there.I've rebuilt a couple of 521 rotax motor's.These are one amazing motor.I've got the manual for this motor.In the rebuilding section it say's a good rule of thumb for keeping you jug's straight is a feeler gauge inbetween the jug's both end's and centre when torking down the jug's to keep it as straight as possible.Just thought I'd throw that out there.Chee's Bud.
Thanks man helped me a lot! :)
@rfphm The 2 wiseco pistons with wrist pin, wrist pin bearings and gasket set I think were 280. ot it off ebay
@BriZav squeeze the rings with one hand and lower the cylinder over the piston. Don't force anything. Make sure you line up the ring gaps with the ring stoppers
Seems like the manifold would have given you a little trouble putting it on after words. Always great watching rebuilds.
good vid man
good work man, hope she runs nice
@BrownLabRanch yeah no problem. glad to help. Nice sled btw
@117nathanmyers i don't know it seems pretty clear to me. you can see the pin in the center of the ring gaps where they have to be when you install the cylinder over the piston. That pin stops the ring gaps from moving to a place where when they are installed could potentially catch on one of the ports in the cylinder. It doesn't matter in a 4 stroke because there are no ports in the cylinders.
@dmainesYZ85 you have to use a torque wrench and you have to use new gaskets
great motor
Thanks. This was very usefull!
@KeepItRoostin658 make sure you tighten them all the same amount then, using a torque wrench, or if you are very experienced you can do a pretty good job at getting them all around the same tightness
ROTAX =MONSTER POWER
@ballockybill they are power valves. dirt bikes have them too but they are internal. They are like sliding plates that close off the exhaust ports a bit and open at higher rpm so that you can still get good power and torque at lower rpm's without sacrificing high rpm power and torque.
good question though
thanks
@ed563 these cylinders came back from the machine shop bored and honed. Ring gap was checked by them too
@KeepItRoostin658 you keep doing it like that and you'll end up with a warped mating surface , every motor has been giving recommended tq specs by the factory usually a looser spec to seat the surface than the second spec to tighten the seal.
@honda1296 who knows? sometimes they last a long time and others don't even last a few minutes. make sure that arrow is pointing to the exhaust
@1skiinIan thanks, i new you needed new gaskets, but do you need to use any sort of gasket seal aswell?
@dmainesYZ85 I usually never do. just make sure the surface is clean and smooth
Gr8 video thanks
Excellent vid, by any chance do you have kinda info for Rotax 447?
@danceGIRLIES101 It's very rare that the piston get damaged without damaging the cylinder as they are in full contact but, if so, you still need to measure the bore of the cylinder in at least 3 different spots to make sure it hasn't worn in a taper or too much in an oval before you figure out the size of piston you will need to order. if your standard piston has become too small you will need to have the cylinders bored and honed for the larger sized pistons. always hone
@maxamo007 I had to get a new one because it was so worn on the joint from rubbing with the expansion chamber, so it wasn't an option
@KubotaTee Thank you for that post. this proves to @DangerZONEpixel that pistons have to be installed a certain way so that the ring gaps don't end at a port
@impakt750 yeah dt's are air cooled so they're very easy to do
@haloass123 yeah, in a 4 stroke they would be. in a 2 stroke you don't have a choice. you have to lign them up with the groove on the piston and install the piston the right way so that the ring gaps are in between the ports. Typically in a 4 stroke you want to have the ring gaps 120 degrees away from eachother. In this case, they are only about 90 degrees because they didn't have a choice because of where the ports were
@danceGIRLIES101 A lot of the newer 2 stroke motors can't be honed and therefore you must send them off to a machine shop to be re-plated or resleeved.
@morominaolenmina yes 670 piston that's 0.020 overbore. The cylinder was too damaged and had to be bored out a bit
@MegaDanTheMan1987 you're going to have to take the jugs off to see if you have a crack anywhere. if there isn't it's probably the base gasket. replace it and reassemble
piston circlip opening can be at 6 or 12 o'clock...
Where did you purchase your gasket kit and piston assembly?
@TheMos2818 Thanks man
@joesudbury yup, seals were done too
@kaseycoleman993
thanks for the explaination
i already found it out myself, its just commen sence when a piston at the turning point to from up to down or down to up the g force will be extreem high on the clip
i think it will never go wrong at a max 5000rpm engine
it wouldt go wrong on a 8000 to 12000rpm engines
what do you think!
@1skiinIan thanks for the advice, i appreciate it(:
thanks for video!
@1skiinIan no its a yamaha dt i already did the top end the other day and it is actualy really simple i put a wiseco forged piston in as i didnt want to let it break in the first place
@iamchevyman5 So set aside a full day and do it RIGHT!
@yak55x You need a clutch puller
@1skiinIan yeah I stopped letting friends borrow my tools years ago . Every time I lent out a tool, it never returned, so I decided I cant be the local rent a center anymore lol.
@Maximusfool The head has been planed for higher compression. I have it tuned pretty well. It's bored .20 over, so maybe 5hp more than stock? so like 120? ish
Oh yea.... thats right.. I never take the manifold off... just the pipe!! Duh lol. Yea ours sucks cause we just have no snow all winter. barely 4 inches in some spots. Good video!
@TheNoisePolluter most of the time they actually snap or bend causing catastrophic engine failure. I've seen it happen many times
@LegittGod39 no, if it's oil injected, reattach the oil injection hose and loosen the bleed bolt untill oil starts coming out of it. after that, pull over the engine with the oil injection lever wide open untill you see oil coming out of the tiney holes in the bottom of the ports (this is with the carbs off of course). also, just to make sure I always mix oil into the first tank of gas on top of the oil injection. (mix at about 100:1)
@1Rugbrn I never have used gasket adhesive. I've never had a problem
@1skiinIan when you replace pistons and/or rings
not sure if it would apply here but many new rotax engines call for the head pipe to be installed befor the torquing of the cylinders to prevent leakage
Do you use gasket seal? and also, im doing a top end rebuild on my yz 85 dirtbike, would i HAVE to use a toque wrench, or would you say two fingers on a ring ended spanner would be ok?
@117nathanmyers The ring gaps should NEVER end in the same spot on the piston in any type of engine. This would result in a loss of compression. In most 2 strokes though, there is a tab where the ring gaps have to be so that they don't spin and catch a port.
@morominaolenmina you mean what overbore?
@1skiinIan i see that now because i took apart my engine i read that in an auto book from the 80s
@GunsClap315 yeah of course! 1500 km's now
@gasperantonic it's from a bombardier Snowmobile
@justinyoface911 yeah just 2 stroke oil
@1skiinIan its liquid cooled its the dtr
hey if i have to crank my bike many times really quick to get it started with full throttle but once started i can start it no probe for like 24 hours and yesterday full of gas started coming out of the expansion chamber near th cylender? what would you say that is bad fuel mix or spark plug?
shouldnt the arrows on the pistons be pointed towards the exhaust.?
to take that motor apart and reassemble do you have to have special tools
Just did a fresh top end on my 787 SeaDoo Rotax, 0.040 over.
@ballockybill I was going to make a drag bike out of my yamaha warrior, or finding a banshee with a siezed engine
I noticed the base gasket moving around when installing the cylinder, shouldn't this have had gasket adhesive installed between crankcase and gasket? I'm asking because im getting ready to do my motor.
@outdoorsman310 no, there are groves made in the piston. This is what I am talking about in the video. you lign the ring gaps where the notches are on the piston. You also make sure once you put the piston in that the ring gaps don't end at any ports
dont the rings sometimes turn when the engine is running?
I have a 97 Skidoo MXZ 670 I don't know how good the pressure tester is but it said I had 75 and each cylinder could that be it or is it this tester
im getting a 2-stroke 125 if the piston brakes on it do you think replacing is a job for a semi novice eg.never taken a 2-stroke apart just 4t's
where can you find the rotax parts? i cant find any for mine.
@1skiinIan i have a problum i was opeing a techumas engine 2 stroke from a snowblower toke the connecting rod of the crankshaft but needle bearings fell all over the place and i dont know how to put them back cause theres no cage to hold then ? can u help me out please i dont know how to put them back on lol (they fall out)
Thankz
hey, i have a question..... i have a 1997 ski-doo formula 583.. its leaking anti-freeze in between the right cylenderand the block.. what should i do to fix this?
@1skiinIan yea i noticed LOL but would u know how to put the bearings back on cause i wanna put it together cause its not mines LOL its my freinds
Thankz
@yoshman139 yes, usually that's the case
@ComicalFerret used lots of 2 stroke oil
What lube did you use or oil?
what happens if there stay a little piece of viber of that cloth in the engine or on the cilinder.I aint NO monteur but still tried to fix my bike after my engine filled up a little with water but cause i aint no expert i made a big fauld with making it dry and a little piece of cloth stayed stuck between the wholes and cilinder how you see it at 6:01min.
It were some really small tinie vibers that stayed stuck but i think vibers went more into the engine and now i got BIG problem won't start :(
Let's say a piston gets damaged in a 2-stroke and you want to rebuild it, do you have to hone the cylinder if it looks good? Or can you just replace the pisons as the cylinder is?
I need to rebuild my 583. How do you get the clutch off?
What oil you use ?
are you using 2 stroke oil or assembly lube?
where did u get the piston and how much
the Exhaust y pipe works too Aline too
@farisman09 Yea i think i might try the heavy grease cause i tryed looking around and like non of them seem to be the rite size cause techumseh fcked them up and also u cant even get parts for these motors
can u suggest any heavy grease i might be able to use (one things for sure iam never ever gonna touch another techumseh engine in my life) LMFAOO
if i cant get it with heavy grease i know were that engines comin ...... into the lake behind my house
Thankz bro
@1skiinIan hey would u know why my 110cc atv wont start well i know that part lol theres no spark. but it cant be cdi cause it starts rarly like if i crank it for 5 mins it MIGHT start for 2-7 sec then off and wont start again.I cant get the vavle cover off to set the timin cause the screws are in a spot were its like impossible to work on this pieace of shit. would u know why iam not gettin spark all wires are good and gas is good but compression isnt that good but cant get to the vavle cover
is this the engine used in lynx rave?
what type of oil are you using? is it ok if i just use something like wd40? or is that too liquid-y??
if coolent gets in ur crank can it blow up ur sled
Yeas what sizi is that piston? 670 cc engine piston??
@allegrobas thanks man
why do you have to assamble a piston clip facing down always!!??
@DangerZONEpixel
"To prevent ring breakage, make sure all port edges are chamfered @ 30 angles with a radius of 0.9 to 1.4 mm"
so suppliers are wrong in this statement?
rotax austria power!