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Adjusting the Valves on the Predator
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Posted by: wolffie
alright so heres the deal. the Predator is a DOHC liquid cooled engine that uses shim and buckets to set valve clearances. if your clearances are too tight or too loose your performance will suffer.
adjusting the valves is NOT as hard as some may think. i will do my best to walk y'all through it. i would also like to thank preddy08, polarisbob, THE_PREDATOR, and the rest of the predatorowners crew for helping me out. also check out preddy08's walkthrough on www.predatorowners.com i am basing my write up on his.
so first step, clean your quad! make sure areas around the engine are pretty good looking. now, make sure you have a good work area for you quad. next, i would highly reccomend a table to set parts on as you will be removing alot of items.
next, remove the gas tank, front fenders, and exhaust system. i reccomend using paper bags to place the specific nuts and bolts in so when you put your quad back together, it will be easier to find everything. label these bas as well.
Posted by: wolffie
the gas tank has a half inch bolt with washer that holds it to the frame, and all the frame mounts are held with a hex head.
ok, if you are sitting on the quad, on the left (stator) side of the motor, there will be two timing plugs. the top one is a 6mm hex head and the lower one is a 10mm. remove both of them.
NOTE= the following view is NOT a good example of what your quad should look like when you do this. make sure she's clean
Posted by: wolffie
with the timing plugs removed, you are now going to set you engine at TDC. to do this. take a ratchet with a small extension and a 19mm socket and put that on the lower nut (where the 10mm plug came off of. you will turn that a hair either clockwise or counterclockwise until you see the "T" lined up in the upper area where the 6mm plug came off.
Posted by: wolffie
The "T" should line up perfectly with the small notch. heres what you are looking for:
Posted by: wolffie
ok, so your motor SHOULD (key word) be at TDC. now you can remove the head bolts. they are 8mm bolts. remove them in a criss cross pattern and set them aside.
now the top of you head should lift off. there is a gasket around it. remove that as well, but be carefull not to "yank" to hard on it and tear it. set both of those items aside on your work table.
Posted by: wolffie
heres what you should be lookin at:
Posted by: wolffie
ok, go to the right side of the quad and bend down a bit (that doesnt sound too good, but just stay with me here), lol, you should see small "timing" marks on the cams. on the left cam (intake cam) you should see a mark at 9 oclock and 12 oclock. on the right (exhaust cam) cam you should see a mark one tooth different from the intake.
heres a picture taken by preddy08 from predatorowners.com:
Posted by: wolffie
keep those marks in mind for when you are re-assembling your quad. ok, now you are going to need to get a feeler gauge from around .002" to say .020" a feeler gauge consists of strips of metal that are different thicknesses. they measure the clearances of the valves and are your key to gettin your machine runnin properly.
Posted by: wolffie
ideally you want your intake sides to be .006" and your exhaust to be .010" slide the feeler gauge under the lobes of the cams from the inside out. its easier to show you with a picture.
here i am measuring the clearance of the exhaust side.
Posted by: wolffie
intake feeler gauge going in:
Posted by: wolffie
now, this sounds a little lame, but when putting the feeler gauge in, you need to make sure not to do to much "wiggle waggling" back and forth. you should put the feeler gauge right up the lobe and push firmly, and it should go in some what firmly. if you have to muscle it back and forth that means it is TOO TIGHT. dont try to force anything either. like i said, it should go in firm, and come out firm.
also, check the clearances from the other two bucket-n-shim areas in order to get an accurate reading from both parts of the cam. RECORD your measurings.
Posted by: wolffie
ok, so chances are things are out of wack. this is where i usually seek the help of slave labor
just kidding. bought seriousely, grab a buddy, this will make things easier.
you will need to loosen the cam tensioner. located on the right side of the quad near where the header raps around. pop the 10mm bolt off (it is really shallow) and set it with your parts. you will need to take a screw driver (i believe a 1/8) and stick it in the slot until it "catches". now, have your buddy turn the screwdrive to the RIGHT until it can be turned no more. either use a vice grip to hold the tension or just have your friend sit there and hold it. this takes the tension off of the cam chain so you can remove it. picture taken by preddy08 from www.predatorowners.com
Posted by: wolffie
heres some common screw driver sizes. i used the one on the far right which, as mentioned before, i believe is a 1/8 (my memory is startin to **** out on me, lol
)
Posted by: wolffie
ok now take the cam stay off (metal piece holding the cams). it is held down with 8 8mm bolts. (use CAUTION when reinstalling these because they are cheap bolts that like to break!!)
now, when taking the cover off, DO NOT just yank and go. wiggle it slightly to get her loose because there are little C-clips that sit on the cam and if they fly off you got some problems. you will then most likely spend the rest of your day with a magnent lookin for em. again, this picture is from preddy08 on www.predatorowners.com
Posted by: wolffie
aight, so throw those parts on a table and take the cams out. make sure you have a hand or finger on the chain because you DO NOT want to drop that into the engine. that =bad.
the cams come out a little stiff as you need to wiggle them a bit. i would reccomend taking the exhaust cam out first and then zip tying the cam chain to your frame while you get the intake cam out.
Posted by: wolffie
ok so your parts table should start to be pretty big now.
Posted by: wolffie
just so you know, the exhaust cam has little "ring" around it. make sure you dont mix up the cams! ok so now you should be looking at da buckets. under the buckets are the shims that control the clearances of your cams.
Posted by: wolffie
USE a magnet to take the buckets out, that way the shim will come with it.
Posted by: wolffie
i organize the buckets and shims a certain way so when i make adjustments it is more simplistic.
if you are sitting on the quad, picture the top two buckets Front left and Front right, and the lower buckets Bottom Left and Bottom right. the top buckets and shims control the intake cam (clearances should be .010") and the bottom buckets and shims control the intake (clearances should be at .006")
Posted by: wolffie
now, you are lookin specifically at the shims. there should be lil numbers written on them, but sometimes they will be worn off. record these numbers in relation to the chart i just showed you, and take them to your dealer with the original clearances you recorder. they should get you in the right direction.
or, if you feel ambitious, or just have a suck *** dealer, order this kit:
http://www.magicracing.com/HotCams-...p_211-1409.html
this is the cheapest you will find, even if you 2 day ship it! in fact, its 2 day shipment beats Rocky's UPS ground!!! this baby has plenty of shims to last you pretty much a lifetime.
**if your clearances are too tight, you need a thinner shim
** if your clearances are big, you need to go to a thicker shim.
example:
you measured your intake clearance at .011" and you shim is a 192, you should try increasing that to say a 197 or 195. (the shim kit i mentioned is in increments of 5.)
Posted by: wolffie
make sure to check clearances for each valve (where the bucket is)
ok, so put the new shims on the little circle marked on the valve, and slide the bucket over it. the bucket should just glide in, DO NOT push it. if it does not just set in, you are not puttin it in at the right angle. it takes a big of finnaglling to get the hang of it.
so put the cams in with the timing marks i showed you before, put the cam stay on and torque the bolts to 7ft lbs of torque and check that your still at TDC (down by the timing plugs) and then release the tension of your chain SLOWLY. now recheck your clearances. if you are doin this on your own, it may take a couple of trys to get the hang of it. it is more time consuming than it is hard.
once you got everything together, DOUBLE, TRIPLE check little things such as timing, clearances, makin sure the cams are in the right spot etc. etc. slap the gasket back on with the head cover and you will be good to go. enjoy your newly tuned machine!!!
if anyone finds ANY room for improvement in this article, just hollar at me
--wolffie
Posted by: TRX23rider
good write up! this should help alot of guys not just people with predators. lots of good info!
btw your inbox is full
Posted by: kc8pnd
Great thread. I must ask, what made you think your quad needed reshimmed? What's some symptoms to look for.
Posted by: wolffie
thanks for the comments guys (trx23rider, i cleaned the box out man )
kc8pnd, most people adjust their valves after every 25-35 hours i believe because they stretch out and you usually hear a slight "pinging" noise after you hit the throttle. For some odd reason, i had the other extreme; my intake side valves tightened WAY UP(there wasnt even any clearance when i checked them) the problem i had is the thing wouldnt start with the starter, you had to manually "pop start it". after the quad was warmed up, the clearances would stretch out and everything would be ok. of course, then after a bit they would tighten up again and you would have to redo the whole process, lol!
Posted by: kc8pnd
I went to the dealer today and talked to chadhix, he said try a plug in mine because it is not starting from a cold start. The plug never fixed anything. I have to choke + pull the carb to airbox tube off to get it to start. After I crank and crank with the starter it slowly fires up, once warm its fine, it fires right up. I think my shims are flat! Thanks for the write up, I might be doing this in the next few weeks.
Posted by: wolffie
so basically your machine wont start worth a ****, but then when you get her started shes ok for abit??
assuming you jetting is right and you have no airleaks, i would say your clearances are too tight.
Posted by: kc8pnd
It started starting hard slowly. I ride it hard most of the time for 1 to 2 hours every weekend. I would say close to 3 to 4 hours a week. As I said before it slowly started to do this, before I had to crank it over 3 or 4 times then a few weeks later choke it and now I have to take the air tube off. I think its the shims. There is no power loss that I can tell, this thing rips when its not spinning.
Posted by: wolffie
does it backfire at all under decceleration? im willing to bet you need some bigger shims. if you got time, tear the beast down and order a shim kit. just follow my guide and you should be fine. if you encounter any questions along the way, just PM me and i can do my best to help you out.
Posted by: kc8pnd
I don't notice any backfiring. It does blow gas vapor back out the carb (white mist) some times. I did order the shim kit, from hotcams so it was $90 
never seen this thread till today, ordered it yesterday. O need to download a service manual from somewhere, I seen one a while back but never downloaded it.
Posted by: wolffie
yeah download it because IMHO, the Predator's owner manual is not very good. i bought one and find it less than stellar.
they dont do alot of "explaining", and there are very few pictures.
Posted by: kc8pnd
I got filler gauge in the mail today, ran out and took the front fenders and gas tank off, removed the valve cover and loosened the cam chain tensioner. I then slid an .06 filler under my intake cam and it would not go in. ran a .10 under the exhaust and it was perfect, just a slight drag like we want. So I removed the intake cam and dropped the little C shaped bearing stop (?) down into the motor, it landed pm the bottom cam sprocket so I fetched that out with a long screw driver. After all all that I started trying shims until I found one that worked for that valve ( long process) I then put the motor back in time which was very easy once you see how its done, I skipped that stupid brass link crap, the chain will work the same no matter what tooth its on. Any way, I put it all back together and hit the start button, BAMM it started instantly just like t use too!! I warmed it up and gave it a ride around the yard and was amazed at how much better it was running. Its like a rocket now that the shims are back to normal + the HMF & air box mod that I done after it started acting up. If you pred is doing what mine was doing then order the shim kit and do this adjustment, its easy, took me about 90 minutes.
Posted by: wolffie
quote:
Originally posted by kc8pnd
I got filler gauge in the mail today, ran out and took the front fenders and gas tank off, removed the valve cover and loosened the cam chain tensioner. I then slid an .06 filler under my intake cam and it would not go in. ran a .10 under the exhaust and it was perfect, just a slight drag like we want. So I removed the intake cam and dropped the little C shaped bearing stop (?) down into the motor, it landed pm the bottom cam sprocket so I fetched that out with a long screw driver. After all all that I started trying shims until I found one that worked for that valve ( long process) I then put the motor back in time which was very easy once you see how its done, I skipped that stupid brass link crap, the chain will work the same no matter what tooth its on. Any way, I put it all back together and hit the start button, BAMM it started instantly just like t use too!! I warmed it up and gave it a ride around the yard and was amazed at how much better it was running. Its like a rocket now that the shims are back to normal + the HMF & air box mod that I done after it started acting up. If you pred is doing what mine was doing then order the shim kit and do this adjustment, its easy, took me about 90 minutes.
thats what i like to hear!!
yeah it isnt that hard of a process but it is alot of "trial and error". good to see things worked out for you.
Posted by: kc8pnd
I was nervous at first but I plowed through, I think I started 6 pm and started it around 7:45 pm, it was just getting dark. I would much rather do all this stuff myself as long as its not real hard, and you don't need any special tools. It really gives you a sense of pride.
Posted by: wolffie
yeah it does give you a good sense of pride. when i first did it, everything seemed so intimidating, but it really isnt bad at all! in some regards, i think it is just as easy as jetting a carb.
Posted by: harescrambles
Here is a chart to show the correct shim to use,,, so's to cut out the trial and error. there are examples on the chart to get you started.....
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