HELP! Ran for 15 minutes, now loud valve tick/rattle!

[Bigace109]

Was out riding around today for about 15 minutes when I heard a louder ticking sound, almost like a rattle in the top end. Took it home, let it cool, changed the fluids (recently started using rotella), started it up again.

1 kick, starts. Still the same sound, and progressively getting worse. Within about 15 minutes, the bike was getting so loud, I decided to turn it off and take it into the dealer to see what they had to say.

Started the bike, 1 kick, and it ran for about 2 seconds, extremely loud now, and shut down. He seemed to think it was towards the front of the valve cover. Now the bike has a hard time turning over (mind you by hand now, Im not going to start it again until I pull the cover). WHAT THE HECK HAPPENED? Someone else said it might be the valve decompressor pin? Never made any sounds previously, always starts 1-2 kicks.

Edited May 13, 2011 by Bigace109

[joman2055]

well the first and easiest thing to do is pull off the valve cover and have a look.

[Lead Head]

Pull the valve cover and check your oil filter for shavings.

[Shawn_Mc]

Could be one of the cam bolts backing out and hitting the valve cover and head.

Where the shims recently adjusted?

[Bigace109]

Finally got a few minute today to pull the valve cover.. nothing looks out of place or damaged at all. Although, I did notice that one of the valve cover bolts was completely loose, and there was since of slight water able to enter the gasket there..

I cant seem to rotate the engine at all now with the kick starter. I have no clue why at this point. The bike seems to be under either great pressure or seized. I really dont have any explanations as to why .. oil was just changed 3 days before, slight metal shavings but nothing too major, always started first kick. Im going to pull both the sides monday and see if I can see anything in the cases out of the ordinary.. any ideas or things to check?

[PBWR450]

Drain the oil on both sides to inspect. About three rides after I bought my used 2002 it suddenly made a loud knock that I thought was up top or to the right side. Sounded kind of like putting an auto trans on a car in park while it's still rolling, if you are familiar with that sound.

Turned out to be two clutch fiber plates had come apart and left chunks all over the place. The problem became obvious after draining the trans side oil.

[Bigace109]

That sounds more probable... question though. If it had anything to do with the transmission, if the bike was out of gear I should be able to turn the motor right? I go to kick it over and it feels jammed. I'm going to pull the plug and drain the oils tomorrow and see what i find.

[Lead Head]

The clutch and transmission mainshaft are still driven in neutral.

[Bigace109]

The clutch and transmission mainshaft are still driven in neutral.

So theroretically if one of the plates was jammed or broken, it could cause the motor to freeze up, if the shaft was suppose to be able to spin freely and cannot now. Sounds like a winner to me. Maybe ill throw in an auto clutch.. anyone run those?

I'll let you guys know what I find out tonight.

[erichshonda]

Does the timing chain have slack. Its possible that the chain tensioner failed causing loss of valve timing. I would verify valve timing . If in time. You will have to go deeper to see what failed. Probably rod bearing since you did find some shavings.

[Bigace109]

So i pulled the plates, transmission oil didnt have any particles, pulled the spark plug and the engine still is difficult to turn over. It feels like its under pressure still and kinda makes a thud sound at a certain position. I really have no clue what went wrong. I baby the thing, keep fuilds changed regularly, let it warm up before riding... here is the spark plug...

[Shawn_Mc]

plug looks fine.

You need a crank.

[Bigace109]

plug looks fine.

You need a crank.

So pull the head, hone it, new piston, crank, bearings, gaskets and that should be about it? What pullers and parts do I need? Anyone run the big bore 500 kit?

Any way to prevent this from happening again? Bike only had about 25-30 hours on it total... ?

[PBWR450]

Unfortunately, you really won't know what it needs until you open it up. When my clutch disentegrated I had expected to spend about 800 but ended up spending closer to 1500. I used all OEM parts and decided to replace alot more than originally planned since it was a 2002 and had only had 1 top end replaced by the PO since new. The good news is that the CRF engine is pretty easy to work on. If you have some mechanical skill and a manual you will be just fine.

As far as tools you will need a special socket to remove the nut holding the crank gear on. A soft coin or washer can be used to hold the gears in place rather than buying the special tool for that. You will need a flywheel puller AND, read the instructions so you don't booger up the ingition side of the crankshaft.

If you need a manual let me know. I have one on PDF that I can send by e-mail. I got it from a link on this site but cannot recall where. Maybe someone else can help with that.

[MELK-MAN]

So pull the head, hone it, new piston, crank, bearings, gaskets and that should be about it? What pullers and parts do I need? Anyone run the big bore 500 kit?

Any way to prevent this from happening again? Bike only had about 25-30 hours on it total... ?

long detailed threads on this very subject, with pictures and everything.. 500bb? why.. Can search that topic too though. Will get way more info fast than waiting for people to post again on a topic that has been discussed many times.. Just trying to give you a fast way to get lots of info.

[Bigace109]

long detailed threads on this very subject, with pictures and everything.. 500bb? why.. Can search that topic too though. Will get way more info fast than waiting for people to post again on a topic that has been discussed many times.. Just trying to give you a fast way to get lots of info.

Thanks

[Bigace109]

Unfortunately, you really won't know what it needs until you open it up. When my clutch disentegrated I had expected to spend about 800 but ended up spending closer to 1500. I used all OEM parts and decided to replace alot more than originally planned since it was a 2002 and had only had 1 top end replaced by the PO since new. The good news is that the CRF engine is pretty easy to work on. If you have some mechanical skill and a manual you will be just fine.

As far as tools you will need a special socket to remove the nut holding the crank gear on. A soft coin or washer can be used to hold the gears in place rather than buying the special tool for that. You will need a flywheel puller AND, read the instructions so you don't booger up the ingition side of the crankshaft.

If you need a manual let me know. I have one on PDF that I can send by e-mail. I got it from a link on this site but cannot recall where. Maybe someone else can help with that.

A manual would be great, pm me! Ive worked on motors before, I think I should be ok here. I have a flywheel puller already, id be willibg to buy anyones old pullers if they are interested in getting rid of them. Maybe ill make a post about it.

I opened up the flywheel side and found black soot and metal shavings stuck to the side. How do you test for a bad bearing, it one that is failing? Also, best brand of bearings/crank? I've looked online a bit, hot rods heavy duty, weisco... preferences? Any upgrades i should do while in there?

[MELK-MAN]

?..

[Shawn_Mc]

The crank puller is pretty cheap. You have to use the correct one with the cap othewise you ruin the end of the crank (but I think yours is toast already).

HotRods cranks are ok, never used a Wiseco, and the OEM cranks arent that expensive. You'd be fine running the one you get the best deal on.

Go ahead and pull the cylinder head off and the cylinder and see exactly what youve got going on before you decide what exactly youre going to do. 20-30 hours is pretty low to loose a crank, but a bad one is a bad one.

[Bigace109]

The crank puller is pretty cheap. You have to use the correct one with the cap othewise you ruin the end of the crank (but I think yours is toast already).

HotRods cranks are ok, never used a Wiseco, and the OEM cranks arent that expensive. You'd be fine running the one you get the best deal on.

Go ahead and pull the cylinder head off and the cylinder and see exactly what youve got going on before you decide what exactly youre going to do. 20-30 hours is pretty low to loose a crank, but a bad one is a bad one.

Honestly, I want to run this bike into the ground.. so if HotRod cranks are just "ok" what is the next best option? OEM scare the S#*$ out of me now since the failure (but then again it could have been my fault or the previous owner). Should I plan on honing the cylinder regardless of the inspection?

Guys, I really appreciate the responses... ?