Timing Chain skipped a tooth

[Khurley424]

A few months ago I replaced a faulty timing chain tensioner with an APE tensioner, thinking the simplicity of design would make for a more reliable bike. Well, riding into work yesterday I heard my bike go from running smoothly and happily to sounding absolutely god awful. I cut the engine, pulled the clutch, and coasted to a stop in the first available driveway. Looking at my bike, I saw the tensioner bolt and lock bolt were both way further out than they were set by myself at. Im almost certain the timing chain skipped. And I know that I tightened the lock bolt down securely. In retrospect APE should include a locking washer in their tensioner kit.

But now I'm stuck with a bike I had to have towed to my house, and I'm incredibly frustrated with the whole situation. My bike is supposed to be a cheap, simple, reliable way to commute to work and school, and to de stress after a day of engineering classes. I'm a fairly broke student, and I'm really not sure ill be able to have a shop fix this (I feel like it will be substantially expensive) and I'm not fully confident to do it myself.

Thanks for tolerating my rant/vent. Anyone have an idea how much it'll cost/how difficult it is to fix?

 

[iSteve]

I think the main problem is you thought using a manual tensioner that has been abandoned by just about every motor manufacturer 50 years ago would be simple and reliable. Ok simple it is but only reliable if you check and adjust it every month or so.

Oh, I'm pretty sure you can fix it yourself it's not that hard a job. And if you put a new yamaha tensioner back in you can go the next 50k miles without worrying about it.

 

[yamihoe]

you have to dig into the whole motor....I JUST put the cams back in my R1 this weekend....so you are in for a fairly long day
Do you understand the concept and how to set valve timing?
of all the things to be OCD and picky about, this is it....the notches have to be PERFECTLY lined up.

You should do a compression test on all 4 cylinders to make sure you didnt bend a valve.


I highly recommend doing it in the dark, after a full days work, and stay up till 4am gettin it all together. :thumbup:

 

[FinalImpact]

That's unfortunate but you may be looking at some parts too as the act of skipping is not all that great on the chain and gears not to mention if the valves did make contact with the piston, some may be bent. That's not to say give up but you need a thorough inspection of all suspect parts and if something is bad it will need replaced.

If we were to present to you a service manual and you were to read through it, you'll see what kind of labor is involved and be able to determine the basic tools needed. If you have time, a place and a mechanically minded friend, you might just be OK!

It would be wise to trailer it to a location you can work on it at.

Scott, could you kindly forward a FSM to this gentlemen? Tks man! :thumbup:

 

[TownsendsFJR1300]

A double lock nut would have kept the tensioner from loosening up but its a moot point now. Issues like this is why I would have replaced the CCT with a new OEM Yamaha tensioner.

As posted above, besides pulling the valve cover and rt side cover, re-setting the marks on the cam and crank is in order. A compression check or even easier yet, a valve check for clearances would show if a valve is bent (cleanances would be considerably greater with the bent valve staying open)

There's many posts on the forum re setting the cam's, checking clearances, etc. It is do-able but you will need a garage, more than basic tools and a good day set aside. (that's without any valves being bent).

PM sent as well

 

[TownsendsFJR1300]

That's unfortunate but you may be looking at some parts too as the act of skipping is not all that great on the chain and gears not to mention if the valves did make contact with the piston, some may be bent. That's not to say give up but you need a thorough inspection of all suspect parts and if something is bad it will need replaced.

If we were to present to you a service manual and you were to read through it, you'll see what kind of labor is involved and be able to determine the basic tools needed. If you have time, a place and a mechanically minded friend, you might just be OK!

It would be wise to trailer it to a location you can work on it at.

Scott, could you kindly forward a FSM to this gentlemen? Tks man! :thumbup:

Sharing a FSM is prohibited..

 

[Marthy]

Just pull the valve & side cover off and line up the timing mark. Then put the tensioner back on. There's about 1 hr of your life. If you don't ear any weird noise, popping in the exhaust or airbox... you're good to go. Make sure everything is tight. Double lock nut is not a bad idea... If it only skip 1 tooth you might be lucky...

 

[TownsendsFJR1300]

Just pull the valve & side cover off and line up the timing mark. Then put the tensioner back on. There's about 1 hr of your life. If you don't ear any weird noise, popping in the exhaust or airbox... you're good to go. Make sure everything is tight. Double lock nut is not a bad idea... If it only skip 1 tooth you might be lucky...

Is there enough play in the cam chain to move it without lifting one camshaft (with the CCT out) should it be off a tooth?

 

[Marthy]

Is there enough play in the cam chain to move it without lifting one camshaft (with the CCT out) should it be off a tooth?

What I would personally do is put adjust the tensioner so it doesn't skip any more tooth, remove the cam cover and side cover to see all 3 timing marks. From there turn gently until the engine get to TDC. From there if one cam is off I'll pull the tensionner all the way out and turn the cams so the mark line up. If a little bit more room is needed you might want to remove the pin from one or both chain slider to get a bit slack from the chain.

Very worst case, I'll pull the timing gear off... not the whole cam! You need to remove one bolt then turn the engine to TDC to remove the other one... I did it many time to get to the cam timing needed. Don't forget to make some reference mark on the cam/gear if you remove it. There's 3 sets of holes... that mean it can go back in 6 different positions.

Anymore than skipping 1T might require a bit more work and $$$. Hopefully everything is fine.

 

[Ben_H]

Like Marty said it should not take more than 2 hours that's what it took me to replace cams. First remove fuel tank battery box and radiator.

 

[TownsendsFJR1300]

I know the FJR will run (real crappy) with one tooth off, two or more, disaster.

I suspect the FZ is likely the same and the OP, shutting down immediatly, hopefully didn't do any damage.

Guess we'll see...


As a side note, for the OP, make sure when checking or re-setting the marks/cams, ALL the free play is TAUGHT in the forward run of the chain(between the crank and exhaust cam) as well as between the cams..

Slop in the cam chain should be between the crank and intake camshaft where the CCT can do its job.

 

[yamihoe]

when checking the valves if one valve is 1 thousandth tighter than the rest and also 1thousandth under the lower spec for the valve clearances would you consider that a bent valve? before running the compression check to confirm obviously..

*backstory...my bike had a valve shim come lose (NO idea how) and it was causing an exhaust valve to stick open and run super poorly...this particular valve is the one that is 1 thousandth tighter than the rest...

 

[trepetti]

Sounds like a burnt valve/seat. If the valve is not fully closing the. The combustion heat sneaking past will damage the seat and make the Val e sit higher and thereby be a tighter fit to the cam lobe.

 

[TownsendsFJR1300]

Any updates?

 

[FZ09Bandit]

A few months ago I replaced a faulty timing chain tensioner with an APE tensioner, thinking the simplicity of design would make for a more reliable bike. Well, riding into work yesterday I heard my bike go from running smoothly and happily to sounding absolutely god awful. I cut the engine, pulled the clutch, and coasted to a stop in the first available driveway. Looking at my bike, I saw the tensioner bolt and lock bolt were both way further out than they were set by myself at. Im almost certain the timing chain skipped. And I know that I tightened the lock bolt down securely. In retrospect APE should include a locking washer in their tensioner kit.

But now I'm stuck with a bike I had to have towed to my house, and I'm incredibly frustrated with the whole situation. My bike is supposed to be a cheap, simple, reliable way to commute to work and school, and to de stress after a day of engineering classes. I'm a fairly broke student, and I'm really not sure ill be able to have a shop fix this (I feel like it will be substantially expensive) and I'm not fully confident to do it myself.

Thanks for tolerating my rant/vent. Anyone have an idea how much it'll cost/how difficult it is to fix?

Compression and leak down test. Here is a tiny piece of advice, go OEM or go home. If these are interference motors (which most dohc motors are) one of three things can happen. 1: nothing, you got lucky. 2: cam spins around out of is normal routine and bam the piston slaps into the valves destroying them. 3: valve goes through the piston.

It's that reason right there why I want to only buy new bikes. People take shortcuts and half ass it molesting the piss out of their bikes. And it's that reaso right there that makes people think that 25k miles on a bike is equivalent to 300k on a car.

I'm not trying to insult you, if you would have asked first it could have saved you a headache because some members have done the exact same thing before. I understand it's fun to ride and the season is coming to an end, but was it worth it?

Get a Manual and do it yourself, probably looking at close to 1000$ and that's low balling it from a dealer. Because if you want to do it right IMO you might as well have the head rebuilt and decked, new head gasket, new head bolts, stems, that's my opinion, I won't take a head job unless all of these things are replaced, and hey get them ported and angled too! Lol

 

[yamihoe]

you might as well have the head rebuilt and decked, new head gasket, new head bolts, stems, that's my opinion, I won't take a head job unless all of these things are replaced, and hey get them ported and angled too! Lol

I thought all the I4's were studded? not head bolts.


and to kinda answer scott's earlier post, the timing chain can be rotated with the cct out but you cant set the cams correctly without at least taking out the intake cam....

 

[TownsendsFJR1300]

Thanks guys..

Well, there's really just the one short cut as the valve cover has to come off in ANY CASE to check the cam mark alignments.

Apparently, if a cam is off a tooth (or just checking), removing one cam shaft sprocket, (2 bolts), saves pulling the entire cam and then you can rotate the cam(s) accordingly. Double check the marks/alignment with the tensioner in (after a full rotation).


And +1 on OEM.

I wouldn't want another thing to have to keep an eye on, adjust. Adjusting an APE is not like putting a feeler gauge in, or clicking a torque wrench. It takes some experiance. Improper adjustment (or lock down) can be disasterous as seen above...


Checking the 07-09 Yamaha shop manual, there isn't any studs, their head BOLTS. There's also no mention that their NOT re-usable (and Yamaha likes to replace anything even remotely needing replacing), so it seems NEW bolts are NOT necessary.


Thinking about it, if the chain (with a bad tensioner) can skip a tooth (a failure while the engine is running), how worn does the chain have to be as it OBVIOUSLY CAN be moved a tooth WITHOUT removing any sprockets/cams, etc? (Ship, I'm starting to talk/think like Finalimpact, )

 

[FZ09Bandit]

O well, torquing head bolts = stretching. Just my opinion and piece of mind.

 

[FZ09Bandit]

I thought all the I4's were studded? not head bolts.


and to kinda answer scott's earlier post, the timing chain can be rotated with the cct out but you cant set the cams correctly without at least taking out the intake cam....

I'm sure you could find some ARPs if you really wanted to.

 

[yamihoe]

The R1 has head studs,, the manual goes into great detail on the torque incriments for the head nuts on the studs.....I had just assumed that the fz6 would have head studs as well....i guess we all know what assuming gets us...:spank::BLAA: