Cam Troubles/Timing?

[Anonymous]

Hi everyone,
Yesterday I replaced the headgasket and all other topend gaskets in my 850. After I buttoned it up I tried to start her up. I got the engine to turn over and eventually start but there was a very high pitched and LOUD squeeling as the bike attemped to idle. I shut it off immidatedly. From that i deducted that something may be off with the timing/cam chain tensioner or something wasnt lubed properly or i bolted something on too tight. Today I went back and opened the head back up. When i installed the cam chain I did just as the book said and lined the no.1 mark with the gasket and no2. pointed to the first pin in the chain and counted 20 pins to the Intake Cam. I also checked with a trusty McDonalds straw in the 1 and 4 spark plug holes to see if the timing was adjusted to TDC and that is affermative. The thing i am curious about is that the lobes on the IN and EX cams are not completly opposite, that is if EX is facing right than the corresponding IN lobe sould be facing left. Could that be the problem (that they are not completely aligned) or is the 20 pin thing not quite accuarate in the book, or I just did it wrong? Or could it be the cam tensioner (a whole other can o' worms)
Any ideas guys??
Thanks,
Justin

[Anonymous]

Hey, the only thing i can think of...considering that the timiing is all correct, is something with the tensioner. i would take it off, clean it thoroughly and ensure proper function. there is a specific procedure for tensioning the chain too...and it should be in your manual. this is all i can think of, use lots of oil too when reassembling.

Ian

[Anonymous]

Re: Cam Troubles/Timing?

Hi everyone,
Yesterday I replaced the headgasket and all other topend gaskets in my 850. After I buttoned it up I tried to start her up. I got the engine to turn over and eventually start but there was a very high pitched and LOUD squeeling as the bike attemped to idle. I shut it off immidatedly. From that i deducted that something may be off with the timing/cam chain tensioner or something wasnt lubed properly or i bolted something on too tight. Today I went back and opened the head back up. When i installed the cam chain I did just as the book said and lined the no.1 mark with the gasket and no2. pointed to the first pin in the chain and counted 20 pins to the Intake Cam. I also checked with a trusty McDonalds straw in the 1 and 4 spark plug holes to see if the timing was adjusted to TDC and that is affermative. The thing i am curious about is that the lobes on the IN and EX cams are not completly opposite, that is if EX is facing right than the corresponding IN lobe sould be facing left. Could that be the problem (that they are not completely aligned) or is the 20 pin thing not quite accuarate in the book, or I just did it wrong? Or could it be the cam tensioner (a whole other can o' worms)
Any ideas guys??
Thanks,
Justin

heyjustin;

If it started up then the cams are probably right or at least close. if it was a high pitched screech it might be the cam shafts are torqued down to tight or not torqued in the proper sequence. did you remove these at all? If it had been a clearance problem with the valves and pistons it would have sounded quite different. or if the chain was hitting the head it would sound tinny. check the camshaft cap bolts and make sure everything there is cool.

[Anonymous]

Hey guys,
I went ahead and loosened the cam bracs and then torqued them down to spec. I will reassemble the head and try it out after dinner. I am hoping not to remove the cam chain tensioner because that requires a lot more disassemblely (carbs, air box and the stubbern throttle cable). But Ill do what i have to do.
Thanks,
Justin

[SqDancerLynn1]

TAKE the time and CHECK the tensioner. Did you remove it from the block? The 850 has an idler gear for the chain, could it be on backwards? Assuming that nothing was dropped into the engine when it was appart, even if the cam timing was off a tooth it would not cause it to make noise CHECK the tensioner and the chain guides. DOn't worry about where the lobes are because it will not tell you anything make sure the sprockets are installed correctly with the correct bolts if they are too long it could be rubbing? did you remove the pistons? did you install new
C clips for the wrist pins

[Dink]

have you re-torqued the head gasket?
Dink

[daveo]

did you lube the cam bearing journals?

[Anonymous]

I disassembled the engine down to the heads but i didnt get as far down as removing pistons. I removed the carbs/airbox assembley and the exuast. I made sure to lube the journels with oil, and tork the headbolts in sequence to spec (27 lb/ft i think). I did remove the cam chain tensioner and replaced its gasket. My buddy Vince did the adjusting to the tensioner. He loosened the nut and closed the screw inside before we removed the tensioner. I am still a little unsure about how that thing works exactly, something about a springloaded plunger? Anyway I think that may be the problem. I will check the idler gear to make sure thats on right. All the bolts are in their respective homes, no extras or nothin!
Oh yeah, what are C-clips and wrist pins? Are those the little rubber half moons for the valve cover? I did replace those.
Thanks,
Justin

[Anonymous]

I have a feeling of what could have happened. I removed the carbs and airbox again to get a look at the tensioner. I figured out how it works and set the spring all the way back. I first made the mistake of closing the tensioner without installing the ider pulley. So i went back and installed the ider pulley FIRST and then released the tensioner to pick up the remaining slack. Or at least thats what i am hoping for. I am waiting for a few parts so hopefully i will be up in running by next week.
Justin

[SqDancerLynn1]

Sounds like you may have figured it out Good luck!

[Anonymous]

arrrrrrghhhhhhh, I went ahead and put everything back together. Went to start it up again and I am hearing the same LOUD squeeling like shes wined up too tight. I made sure to lube the journels again and oil is getting up to the cams. So thats ok, i guess.
I am unsure what to do now.
The only thing i can think of is strip the engine back down to the heads and take a look around. I hope nothing dropped on top of the pistons and killed the cylinder walls.
Could carbon deposits that i cleaned off get lodged in the combustion chamber?
Any ideas all?

[Anonymous]

Maybe you could go into more specifics as to what you did for repairs, what the squeeling sounds like (constant, pulsing, etc), when does it squeel (all the time, only at idle). Have you tried turning the motor over with a wrench to check for any problems? Have you run a compression test?

[Anonymous]

Is your starter jammed up?

[Anonymous]

When i attempt to start the bike the engine turns over freely. Once the engine starts to pick up and combust some fuel theres a squeel in time with the engine. The bike doesnt want to idle if i give it more gas it reluctantly and very loudly squeels. The engine dies if I let off the throttle. One time I gave it a little throttle and saw a bit of smoke...not a good sight also smells a little. I was tempted to dump the throttle just to see if i could shoot anything through, then i came back to Earth and figured that would probley do more harm than good.

[Anonymous]

Is your starter jammed up?

I havent looked at the starter. I do have an idea how it works tho. Its basically a motor connected to a small gear that turns the crank in the bottom of the engine. So could the starter be sticking so that once the engine is started the starter is still engauged and is spinning at Mach 11?
Wow I think I just convinced myself to take a look.