took the bike in for a valve adjustment a few weeks ago.  they also did an oil change as it needed it.  took the bike out for an hour this past thusday, another hour on saturday and then a half hour today.  bike ran great but then sputtered once, almost like a bog and then again, but on the second one the motor locked up and it locked up the rear wheel.  kick start is locked up tight.  now i'm huge into sleds and i know my 2 stroke motors.  if this happens on a 2 stroke you either blew your top end or your bottom end.  but what could be my problems on a 4 stroke?  i have a total of 2.5 hours since my service at the shop, so i'm kind of wondering what the hell happened.  if i needed to have vlaves replaced i would have thought they would have told me that.  what are my possible problems?

You won't be able to tell what happened until you tear it down. Start at the top and work down. Did the shop put oil back in the bike?

i bet the intake cam siezed.  wont know until you take it apart but thats my 1st guess.  they over torqued the cam cap bolts and the center journal siezed.

if so i can be fixed pretty cheaply

yes before i left the shop they started it and showed me the oil level.  should i bring it back to the shop and have them do fix the issue?

It depends if you trust them or not. A sleazy shop will find the problem whether they caused it or not and charge you an arm and a leg to fix it. A very honest shop will find the problem, admit they screwed up and fix it for you free of charge. How mechanically inclined are you? They are pretty easy engines to work on especially with the manual but you kind of need to know what you're looking for to notice something wrong.

Is the bottom end all original ?   My sons 02 yzf seized the crank a few years back. I just happened to be on it at the time as we had switched bikes for fun. As you describe it , it sounds exactly as mine reacted just before seized. It was crank. The rod stuck. Ended up getting the head redone and doing a total bottom end. I would say at that time it had roughly maybe 200 hours on it.

i'm not sure if the bottom end is original or not.  i just bought it in june.

as for the shop, it used to be a dealership where i had my ski-doo's serviced, they closed up shop and thier head mechanic stayed and opened up a repair shop, so i know they are good.  i can tunr wrenches but i don't have much experience with the 4 strokes, with sleds being mostly 2 stroke my experience is mostly with them, but i have plenty of friends who can help me.

my buddy told me to take the plug out and see if it would turn over, said if its a valve it would turn with no plug in it.  no go, still locked up.  the plug looked fien with no deformation or metal on it.  color looked good as well, maybe a bit darker than perfect but def not lean.  i guess i'm going to have to start really tearing into it some night this week and into this weekend.  if i had to guess i would say bottom end is junk.

Did you check the oil filter for shavings ? If there are shaving, for sure you will have to tear down completely . It would almost be impossible to flush them out. I had shavings all over.  You could see where they had scarred the oil pump.  All in all I think I ended up spending about $1100 on the whole thing. Valve job by Forward Motion. And another $700 in parts. All new bearings, seals, gaskets, etc. If you can wrench and have a manual you should be good to go. I found all the info I needed for tear down and rebuild in there. And if you can't find it there . You can find it on this site. Good luck.

Edited by sndmn2, 07 August 2012 - 06:32 PM.

You said the kick start wont kick through. Are you sure its not on the transmission side of things? Just a thought.

if it was on the trans wouldn't it lock everything up?  i was abel to put it in neutral and push it for a ways.

yes if it the cams wont turn over it wont kickstart

i'll bet all the hair on my head its a cam siezure issue

SUnruh, on 08 August 2012 - 04:55 AM, said:

I thought you were bald?

so i'm hoping tomorrow i can leave work early and get a jump on this thing.  no time tonight so all i did was drain the oil and check that out and then take the filter out.  besides the fact that no mater how many times i run it and drain the oil it still looks like mud, the oil didn't have much in it for metal.  when i took the filter out i noticed some fine metal in that small amout of oil in the filter cavity.  there was some dirt and fine metal in the filter as well, tought to see though, the fiter was dark grey from the dirty oil.

my bike kick start seized but the motor still turns if i roll it in gear can anyone help?????

Motoguy please start your own thread instead of hijacking others. As mentioned on another thread you need to tear into it. Even if we had X-ray vision it's still not going to fix itself so you're going to need to get in there anyways.

Tb19- sorry, does the oil look like coolant got mixed with it like a blown head gasket?

no, no coolant, it was just grey and dirty.  when i bought the bike the first thing i did was an oil change.  i have done 4 in the last month having only ridden it 8 hours total and it still is the same color as the day i picked this gem up.

so the motor is out, started from the top and worked my way down and it seems as though the bearings on the rod are cooked.  i'm going to split the cases and check out the bearings later this week.

what do i have to do to split the cases?  i'm trying to limit the amount of stuff i have to take apart in order to replace the rod bearing and rod.  what is the minimum that i have to do?  i kow the flywheel and stator, but can i leave the trans intact?