Just did mine for the first time. A couple were a bit loose but all within spec. I also went with .004'' and .006''. Not much space to get the rear cover off, so i just moved it aside and had enough room that way.

 

How many miles and hours are on it?

 

Mine has 190 miles and 18 hours on the clock.

 

Is there a set recommended time for this? Or should a guy (by the sounds of it) check them straight out of the box?

Thats kinda funny after that long of riding they're tighter!? You'd think with everything breaking in they'd be looser! Imagine what they were like new!

 

Just be sure you do this on a cold engine or else everything will be way of. Also be sure the ends on the rocker arm is paralell to the valve stem when you put the feeler gauge in between. Usually they seems to be too tight at first but when you move the feeler gauge around a little bit, the tappert end will move in place and the gap will widen up a bit.

 

The engine was 35* after setting all night. Couldn't get feeler in between the valve and the rocker arm. Had to loosen the lock nut, back off the adjusting screw, insert correct feeler gauge, then tighten adjusting screw to correct width. Double checked with gauge after tightening lock nut. Same as I've done for years.

 

i put cams in mine out of the box but checked the OE lash first. they were tight. i was surprized. but also it is critical to be accurate as to TDC. just a few crank degrees and you are on the lobe.

seems few have read the manual. the only way to ensure TDC with the engine assembled and not going through the hassel of dead stick timing is to use the crank locking pin.Cam chain and guide wear can move the cam timing enough. and you really need to know your crank timing marks. the only way to be sure, at least the first few times is with the crank locking pin. and for me, guess i am a little anal about it but it is extremly important, a degree wheel.

the locking pin is the same bolt as the secondary clutch spreading bolt. it installs just to the PTO side of the front driveshaft. in a recess so it is a little tricky to find the first time. i thread in the bolt by hand as i am rocking the engine slightly and it can be felt as the pin slowly locks the crank. once hand tight the #2 cylinder, with cam sprocket marks level with the head, will be exacly at TDC. then i set up the degree wheel at "0". after working with the #2 cyl, the engine is rotated backward 280*. the #1 cyl will now be at exactly TDC. at these points you can make your own timing marks on the Mag or at least note exactly where the marks are so it will be easier the next time. i also use a machined block to line up the cam sprocket marks. i just dont eyeball anything. it is all too important.

 

It's not rocket science. Just a knat's ass off and the #1 or #2 won't be centered in the sight window. Yes you can use a stick or block on the alignment marks on the timing gear if you need to or are cockeyed. On a brand new engine, there should be no slack in anything.

 

true, but the thing is the baseline. and checking things at high mileage.

if you dont know what it looks like good, how do you know when it is bad?

also these are odd fire engines. so the crank marks are not the same for the two cyls.?

remember when checking valve clearances you are also checking cam chain/guide wear. it is good to do things exactly the same everytime to find problems before they are problems? Murphy's Law is in full effect here. "It wont be a problem untill you are miles from home with no tools". "

i also have to giggle when i read about these guys who are all over their A/F ratios with Laptops, O2 sensors and dataloggers, dual tunes then say cam timing is "no big deal". HA HA. fools.

 

lol. Yea, they crack me up too. With a high mileage engine, it is a little more critical to make sure you are at TDC in that like you said, cam chain wear, etc. I guess a fella could gentle rock the engine back and forth to watch if the chain turns or if there is slack in the components. In my case, a worse case is the valves are a tad loose IF they were spot on in the beginning which I don't think they were. I've never encountered all valves tight before, but at least they were consistant. Made me second guess what I was seeing, which in the end was good. Made me double check my work. Regardless, it starts well, runs like a scalded dog, has NO valve clatter or ticking. Better too loose than too tight. But, I think it is spot on correct.

 

I wouldnt turn the engine backwards cause of the timing guide will suddenly be on the tight side of the chain. Maybe it isnt a big deal but it is just something I have learned years ago. It may also give you false reading on the cam because when the engine turn the right way again, it will take up the slack from the timing chain.
Again maybe not a big deal.
Does anyone have any idea why Rotax didnt make these engines with hydraulic lifters?

 

I'm not suggesting turning the engine counterclockwise. I just meant putting slight pressure on it backwards and forwards to see if there was any slack in anything. DO NOT TURN THE ENGINE BACKWARDS.

 

come-on man....what can it hurt? where did you get that? maybe you dont rotate your radial tires either? the cam chain slack is taken up. if it isnt there would be a problem. maybe you know something the Rotax engineers dont?

BTW counterclockwise is backwards. the engine runs clockwise.

 

Of course counterclockwise is backwards. That's why I said don't turn it that way. I, unlike you am not a rocket scientist. lol.....I don't know why we can't turn it backasswards. I've just always been told to only rotate it in the direction of operatin. Never thought to ask. Didn't feel I had to. BTW, I don't rotate my radial tires. I run them on a Mustang GT and they are not swapable, in that they have an arrow on them showing the direction of rotation........sort of like our Can Am belts. I run wider in the back than the front. lol

 

Ya don't spin it backwards in case of loosening the stator bolt... Twitch you would need to lock the crank, remove stator cover, replace the gasket most likely and remove the bolt completely, re loc tite it..... Etc etc.
... You can turn it back wards, there is just no reason to. When you turn over the engine the cams/lobes are naturally changing the load direction on the chains as you spin it...
Not rocket science, just mechanics.
All slack will betaken up by the chain tensioners. IMO, it is just as important to set valves as it is the chain tensioners. ..., before setting the valves.

 

In the end we all want the same valve adjustment, one that is not to tight or to loose, like the Goldie Locks porridge, one that is just right. Walrus I know from your posts that valve adjustment is something you have done before, did you check and see what the valve gap was before you did your adjustment, Can Am service manual for my 07/500 allows the valves to to have a gap between, intake, .0024 to .0055 in and exhaust, .0043 to 0075 and they suggest take the mean for a feeler guage to get a proper adjustment. I am not saying you are wrong just that if you used a .004 and .006 the gap could have felt tight, just saying. i am not sure what gap the 2012 800 call for, it seems 004 and 006 is what you have set yours at.
I see no reason why the motor could not be turned counterclockwise if done properly, the sevice manual suggests to turn the motor counterclockwise when checking the camshaft timing gear marks are parallel to cylinder head base, doing #2 first then #1, it appears to me that no harm will be done if done right. I was told by a Can Am mechanic not to turn the motor counterclockwise with the camshaft timing gear bolt as if it were to come loose and not get loctite and retorqued properly that it could vibrate loose and cause damage. How accurate does top dead center need to be, well with the marks on the camshaft timing gear parallel with head and the 1 or 2 on the magneto I am sure most people would do just fine at setting there valve gap, my thoughts are that the crankshaft could be 5 degrees before or after TDC and still be fine for setting the valve gap but TDC is what we aim for. Turning in direction of rotation puts the moving parts in there best position for accuracy and also it will tighten the 14 mm Allen bolt not loosen it. I do my valve adjust and timing chain tensioner check and adjust at the same time I remove my CVT cover to check clutchs and belt and sevice one way and turn motor over using the primary clutch with spark plugs removed to gap or replace. I hope I have the information that I put here right. I set my valve gap to .003 and .005 and use a .004 and .006 to see if they are to loose and a .002 and .004 to see if they are to tight, a bit more work but it gives me peace of mind that I have them close to right and recheck gap after all is done. I do not run the motor hard or hot.

 

In the end we all want the same valve adjustment, one that is not to tight or to loose, like the Goldie Locks porridge, one that is just right. Walrus I know from your posts that valve adjustment is something you have done before, did you check and see what the valve gap was before you did your adjustment, Can Am service manual for my 07/500 allows the valves to to have a gap between, intake, .0024 to .0055 in and exhaust, .0043 to 0075 and they suggest take the mean for a feeler guage to get a proper adjustment. I am not saying you are wrong just that if you used a .004 and .006 the gap could have felt tight, just saying. i am not sure what gap the 2012 800 call for, it seems 004 and 006 is what you have set yours at.
I see no reason why the motor could not be turned counterclockwise if done properly, the sevice manual suggests to turn the motor counterclockwise when checking the camshaft timing gear marks are parallel to cylinder head base, doing #2 first then #1, it appears to me that no harm will be done if done right. I was told by a Can Am mechanic not to turn the motor counterclockwise with the camshaft timing gear bolt as if it were to come loose and not get loctite and retorqued properly that it could vibrate loose and cause damage. How accurate does top dead center need to be, well with the marks on the camshaft timing gear parallel with head and the 1 or 2 on the magneto I am sure most people would do just fine at setting there valve gap, my thoughts are that the crankshaft could be 5 degrees before or after TDC and still be fine for setting the valve gap but TDC is what we aim for. Turning in direction of rotation puts the moving parts in there best position for accuracy and also it will tighten the 14 mm Allen bolt not loosen it. I do my valve adjust and timing chain tensioner check and adjust at the same time I remove my CVT cover to check clutchs and belt and sevice one way and turn motor over using the primary clutch with spark plugs removed to gap or replace. I hope I have the information that I put here right. I set my valve gap to .003 and .005 and use a .004 and .006 to see if they are to loose and a .002 and .004 to see if they are to tight, a bit more work but it gives me peace of mind that I have them close to right and recheck gap after all is done. I do not run the motor hard or hot.

Sounds right on the money to me. I did check in the beginning on #1 cylinder. I tried .00125 and it wouldn't go in. So, when up to operating temp, and these things grow in length, there were definitely valves not closing.

 

of course, it is your machine and you can do whatever you like. in the "good old days" things were "simpiler" and more straight forward. modern engines are just a little more tricky and tolerances are tighter. and there are plenty of ways to screw-up something that seems so simple.

learning to do this properly on these Rotax motors will serve you well if things get more complicated, for example, you need to pull the heads someday.

plenty of folks will tell ya it's "good 'nuf", but alot of those same people have unexplainable problems later.

i didn't design these motors. so i tend to listen to the people that did. and i know that cam timing is everything.

 

All true, but this method isn't much different than setting the valves on a solid lifter hotrod. I bet there aren't a handful of folks on here that have ever set a points gap either.

 

can am timing is done counter clockwise
set the rear cylinder (1-2) then counter clockwise to (1-1)
as far as the perfect spot to set valves lol, these heads can be set sitting on the bench, the gap between lobes is about 30 degrees (a guess but thats about how far you can turn a relaxed can am head that does not have a chain on it)
the only reason you would not want to turn that motor would be if your timin was off, other than that turning it backwards causes zero issues, the chain does not have a tight side, if it did you would need to change the chains before it jumps time and trahses your valves

 

Are you saying start with the #2 jug, and if so what diff does it make.

 

the correct way to set timing is start with number 2
per the can am manual

I have no idea why its timed like that but that is the way the book says to do it
I have done it that way every time I have done one and yet to have a problem

if you are setting timing I would assume that if you started with 1 you could turn it clockwise to 2 but that is not what the book says to do

 

I did #1 first. Only difference I see is if you started with #2, then you would need to cycle the chain around more to get #1 to TDC.

 

again, you start with #2 cause that is where the crankthrow for the locking pin is. and Rene1 made a good point and that is the Mag bolt. i am almost certain that the "Can-Am clunk" at idle is a loose Mag rotor banging against the crank key. it sounds like a lowerend bearing at idle.

so, because i have the lock pin (bolt) just threaded out to turn to #1 TDC, the final step is to spin the engine clockwise to check the work, then lock the crank again and torque the Mag Bolt/cam sprockets/set chain tensioners and torque primary clutch bolt. there are details and personal preferences you will develop but it must start with the basics.

 

Do you have a pic of the locking bolt location? See if I got this right. Put in locking bolt. Rock engine to get it set to TDC on #2. Adjust #2 valves. Rotate engine backwards 280* verified by a degree wheel to get to TDC on #1. Set Valves. Then check work. Also, retorque Mag Bolt because you probably loosened it by rotating engine backwards. Without a degree wheel, TDC on #1 is a guess at best? This seems like rocket science to me.

 

Walrus, you done right first time, your valve setting gap is good i am sure, this is another thing, I was just saying about turning motor back wards and yes the reason to start at #2 is the location for the locking pin bolt to match up with crank notch, no notch at #1 position. The things you learn from a post and a little research and helpfull posters, got to like it, everyone.

36 Hp VW with mechanical advance, been there done that.

 

Walrus, you done right first time, your valve setting gap is good i am sure, this is another thing, I was just saying about turning motor back wards and yes the reason to start at #2 is the location for the locking pin bolt to match up with crank notch, no notch at #1 position. The things you learn from a post and a little research and helpfull posters, got to like it, everyone

Well, you start second guessng yourself. Why all the second and third chances to get the TDC right? I mean, TDC for #2 seems stright forward enough. But why put the marks on the cam sprockets? And why put the #1 and #2 in the sensor sight hole? If all you had to do was lock up the crack, and put a degree wheel on, why all the second chance marks to get it right? To me, if you get the timing marks right, yes with a block of some kind or measure with a ruler or by dead eye dick sight, and you center the #1 or #2 in the sensor hole, not just so you can see it but really center it, it's gotta be TDC isn't it?

 

The base circle of the cam is huge. As long as your not on the up ramp or down ramp you can set your valves. You guys are making this way more complicated than it really is. Example align the flats of the cam sprocket turn motor in either direction check valve clearance then rotate back past and check it . The freaking base circle of the cam is perfectly round. The margin of error is big either side of top dead center. Putting in the locator pin and using degree wheels is going to get the exact same results.

 

That's what I was getting at. I've never had trouble. Those marks are there for a reason. They are tools to help get to TDC. Locking it up is an option, but probably not needed.

 

Now I`m a little confused, it seems pretty straight foreward on the sticky,so wich method is the correct way to do it,this is an important task,which method does a reputable dealer use? The first method is fairly simple the sticky method the second way is a little more confusing and time consuming.

 

I'm thinking sticky. There are times when you want to lock up the crank, but not neccesary for valves. Otherwise, why put the #2 in the sight hole or timing marks on the #2 cam sprocket. Seems redundant.

 

it really doesn;t matter about the crank position, when you line up the 2 marks on the cam sproket to be level with the head, the cam(which is what is really all that is important), is in the TDC position. meaning both valves are closed, and the cam is in the upmost center position for setting valves.
doing this, it doens;t matter about guide wear, chain stretch, loose tensioners etc....the cam is exactly where it needs to be....go to work.

 

Thanks rene. Maybe we can put this to rest now. Maybe.

 

Maybe,
but then my curious mind asks,
if we can use the lines on the cam gear alone to set the proper position the cam should be to set valve gap why does Can Am have the proceedure that the CPS sensor be removed and line up the 1 or 2 to a notch on magneto cover, as lunatic pointed out there is enough room on the cam that is off the lobe ramp that to be dead on accurate is not nessesary to do the valve gap job. I am just wondering if Can Am is wanting us to look deeper if in doing there proceedure of line up the 1 or 2 mark to notch that if the lines on the cam gear do not line to be parallel with the head.
I will gladly use the cam gear marks as rene1 has show knowing as lunatic said there is lots of room on flats of cam so no need for concern, thanks for this easy to do tip rene1.

 

Maybe,
but then my curious mind asks,
if we can use the lines on the cam gear alone to set the proper position the cam should be to set valve gap why does Can Am have the proceedure that the CPS sensor be removed and line up the 1 or 2 to a notch on magneto cover, as lunatic pointed out there is enough room on the cam that is off the lobe ramp that to be dead on accurate is not nessesary to do the valve gap job. I am just wondering if Can Am is wanting us to look deeper if in doing there proceedure of line up the 1 or 2 mark to notch that if the lines on the cam gear do not line to be parallel with the head.
I will gladly use the cam gear marks as rene1 has show knowing as lunatic said there is lots of room on flats of cam so no need for concern, thanks for this easy to do tip rene1.

We need the 1 or 2 along with the marks because there is a 50-50 chance that the 1 or 2 will be visible with the marks indicating TDC and a 50-50 chance the numbers won't be there when the marks are parallel.. Remember this is a 4 stroke.