how to remove cam chain 03 predator 500

gregmiller185 · #1 (**permalink**) 10-22-2011, 10:28 AM

Hey guys, just picked this up a couple days ago from the dealer i work at. Someone traded it in and I got a deal I couldnt refuse on it. I don't really have much information on it but hopefully someone can answer a couple questions.

It runs on race fuel so I'm wondering what else may have been done to it, but on the side of the head it is stamped NICHOLAS and had a Nicholas Racing sticker on it. Is this who would have done the motor work? I would like to see what octane fuel I should be running.

Anyways, I'll probably be taking it out to the motocross track tomorrow so I can finally ride it.

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**Bruce!** · #2 (**permalink**) 10-22-2011, 03:14 PM

Welcome to the board!

starpuss · #3 (**permalink**) 10-22-2011, 03:26 PM

Thats nice!!

Let us know how your Test Run was!

joshr08 · #4 (**permalink**) 10-23-2011, 02:40 AM

well i think you got yourself a nice find. not many of these motor around coming up for sale anymore. if you check the carb it should also be engraved. No telling without pulling it all apart to tell what build you have tho. This company is now out of business. I know they did builds from 520's up to 574's i think

gregmiller185 · #5 (**permalink**) 10-23-2011, 03:25 PM

thanks, well i took it out today and it didnt go so good... I went out and did a few laps then i let my brother do a couple laps, but then he stalled in a corner and I have not been able to get it to fire back up since. I have cleaned the carb and changed the spark plug and its definately getting fuel and is getting spark. So it sort of sounds like it could be timing?

Also, when I put my hand over the exhaust and turn it over it sucks in. burnt exhaust valve? cam chain jump? I'm not sure how stalling it could cause this so any info or something I could try would be helpful. I'll be doing a compression test possibly later tonghit and maybe a leakage test.

Oh, and I didn't see any markings on the carb but I'll take another look as I wasn't looking for any engraving when I had it off.

joshr08 · #6 (**permalink**) 10-23-2011, 04:00 PM

man i hope everything works out but if it stalled and exhaust is sucking in thats not a good sign. you maybe finding out what the inside of that motor looks like sooner then later. if you dropped a valve top end is shot. 1 tooth on the timing will smoke the head and valves and piston most of the time.

gregmiller185 · #7 (**permalink**) 10-23-2011, 05:45 PM

I pulled the rocker cover off and lined up one of the timing marks on the exhaust cam gear flush with the cylinder head surface, but the timing mark on the intake side is about a tooth out. Now I don't have a service manual but this doesn't seem right, also when i turn the engine to TDC on compression stroke i cant see any marks on the flywheel through the hole. Could the flywheel key be sheared or is there even any marks on the flywheel for TDC.

Heres a couple pics of cam timing

intake

exhaust

joshr08 · #8 (**permalink**) 10-23-2011, 06:07 PM

theres 2 sets of marks on the flywheel. theres a set of 3 together (not the one you want) then theres a I next to a T you want the I as your TDC the marks on the cams and flywheel only line up something like ever 27th revolution or so. those are either webb or nicholas cams as stock cams dont have those numbers engraved in them. did you do a compression test yet? That timing does IIRC look pretty close there are gold links in the timing chain if you take the clutch cover off and pull the clutch basket there also a mark on that gear on the crank. then turn it so the gold links and all timing marks are aligned to make sure everything is where its sposed to be. you can also goto my forum to get some more help from a buddy of mine that knows a bit more about these motors then i do. www.polarisproriders.com post there leo will respond.

gregmiller185 · #9 (**permalink**) 10-24-2011, 05:42 PM

I see what you mean, I checked in the manual at work and cam timing does look about right. I did a compression test and got 135 psi. To me this seems pretty low for this type of engine but what should a stock predator make? I also pulled the stator cover off and flywheel bolt and when I looked in the keyway I could not see a key. Before I bought the quad I had to replace the starter one-way clutch, and if i remember correctly it was pretty obvious that the flywheel key was intact. I'm gonna bring home the puller tomorrow and check for sure.