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Cam chain/ timing chain

Started by FJTillDeath, November 24, 2011, 06:30:05 AM

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FJTillDeath

Something thats troubled me for a while has gotten a bit too much. I am going to try this using the correct words for extra clarifications. For reference a cam chain is probably a timing chain or vice versa or the whole setup/ drive

When I replaced the tensioner gasket  a while back(as some of you recall) I thought I had done everything correctly, though now I am not so sure as the steps seemed a little confusing. So I want to ask.

When I took the cam chain tensioner out:
I satrted with the cap bolt, then the 2 securing bolts and pulled the unti out of the engine(cylinder block I think)
I cleaned it.

When I put it back in I:

First set it to its tightest setting(fully compressed it), when I applied pressure to one part, it auto adjusted itself back to its lowest setting(popped back out)I purposely did this to see how the mechanism worked.

So I repeated the above making sure it did not pop out of setting. I then Slotted it into its fitting and started tightening it starting with the 2 securing bolts and then the bolt cap(i did tighten the bolt cap a little however as the spring would pop out if I didnt), expecting it to click into its correct setting automatically..I however did not here it click. At all. I thought "ok maybe its still cool and Im not supposed to hear it". Other info, it was really difficult to put back in its slot and I had to use a great amount of force to get it in(was worried I would bend the springs or damage them), stay in and tighten it up again - the spring was always stopping it from sitting nicely. So basically I think its either at its max or lowest setting currently

I do know that I installed it the correct way up/down(one way cam was facing down), but I dont think I adjusted it to the right setting as the manual said"set the tensioner rod to the length listed in the specifications - and as I said I had just set it to its full setting and just put it in the motor -against my better judgement I was following what somebody told me to do - as I said I didnt think anything of it at first as I had no problems riding the bike afterwards.

Now I had thought all was well and my oil leak was gone, but as noted the oil leak was not. Every now and again I heard lurching sounds from the motor that I thought was just the motor being cold. Now the sounds have gotten progressively worse. Now when I am at idle and hold the rpm range at about 2000rpm there will be a random clunk from the motor that sounds a lot like a chain is missing a link or slipping on a sprocket. T0compare it sounds as if the chain on your sprocket sitting way to slack that might skip or slip off the sprocket. I am not sure how the internals of an engine work, but in some of the mebers pictures I have seen a chain inside the motor that runs on gears which I am told is the timing chain or the chain drive. Its not only when I idle as the noise also happens when I sometimes pull off or ride in a slightly lower rpm(1500 to 3000, though I have heard it at 6000)

So I took the FJ to a friend of mine who deals exclusively with old bikes (moto martin, verdera etc - he also collects old and scrapped/ totalled bikes and restores them) and while listening to the bike he said it sounds for definite that the timing/cam chain is too stretched. He put his hand over the exhaust muffler asked me to rev the bike a little and when he removed his hand there was a sound from the motor like a chain lurching inside, he said then that it is definitely the timing chain.

He as never worked on an FJ but his knowledge of old mechines is quite good so I wanted to come to the forum and ask for first hand opinions.

Did i replace the cam chain incorrectly, if so, how must I do it as I am sure I followed the manual.
I know that if the timing chain snaps it can rip through the top end of the motor - my friend says he thinks that will happen and very soon, do you guys agree?
If i did infact replace the cam correctly does this mean I need a whole new cam chain and timing chain assembly? or what do I need.

I know the only way yopu guys can make a 100percent accurate guess at this is to see the bike for yourselves and thats whyu I am hoping to give as much description as possile, if you guys need me to tell you more I can, if it requires taking the motor apart that I can do too as I have another bike to use..

Thanks for the support
Jesse
Life behind bars - is actually quite thrilling

andyb

You don't absolutely have to set the proper length on the tensioner at installation time really, the trick you missed is installing it and then turn the motor over by hand (a big socket on the bolt that holds the ignition timing plate will do, it's on the left side of the motor [assuming you're sitting on it], the cover is 4 screws to remove).  Important to turn the motor over in a forwards direction, incidentally.

I'd imagine that you camchain isn't really that bad, though it's possible.  More likely the starter chain is the one being noisy, and it's pretty major surgery to get access.  There's no tensioner on it, kinda a silly design really, and it gets pretty noisy.

If you want to be certain, you can pull the valve cover and check the cam timing.  With the cover off, looking through the largest cam caps (they're in the middle), you'll note they have little holes in them.  As you turn the motor over by hand (forwards, never turn an engine over backwards without good reason), you should be able to see a pair of small drilled spots go past.  When you see them align, then you can refer to the spark plate (ignition trigger) to see where you're at, though ideally you'd manually check and find top dead center (TDC) and see if everything lines up.  Honestly, it won't, as it's a production engine and various tolerances change engine to engine, but you could compare the two cams and see how much difference you see between them (they shouldn't be too far off when new).

Honestly?  Do a compression check, as that'll tell you roughly where your cam timing is.  Eventually the starter and camchain will need replaced, but unless you're really comfortable splitting the cases it's probably ignored.  When it does become time to split the cases (for this or any other reason, i.e., trans is not working or such), then you should definitely rering things, fresh bearings, new chains, new gaskets, new chainguides, the lot.  No point in opening it up unless you're doing it all and doing it right, or it'll all have to come apart anyhow again eventually.  It's possible that your timing jumped when you put the tensioner in, a compression check would show it (all four would be low).  Typical chain slap is just something to live with otherwise.


FJTillDeath

Thanks Andy, I'll definitely take note of it to check.

I finally found an ex FJ owner(from many many years ago) last night, had a chat with him and so on> He told me to bring the bike around and would have a look at it. Turns out he is in my club and says he wont charge me for anything other than the parts I need. I asked him if I could watch him when he works on the bike just so I can learn a bit myself..

Well when I finally drove the bike to the guys house last night he said that from the down the street he could hear the chain was out and about to snap, he said all is definitely not well with the motor. Just on hearing the bike, letting it idle and so on he said that the timing chain is either severely damaged, the bike may have dropped a valve(woorst case scenario) or the starter unit may be suspect. He said there was also a lot of missing in the bike and so the carbs were unbalanced and probably had holes in them.

Due to the shitty weather last night we couldnt get into the motor to actually check things out, but tonight or on the weekend he said he would open her up and have a look at everything starting with the runners and chain and so on. He said that although the body work(apart from the side scoops) had been well kept but many of the internals have not been looked after.

So it seems like the bike will finally get some professional attention and a good service..will report back when we find what horror awaits and maybe include some pics..
Life behind bars - is actually quite thrilling

FJTillDeath

So, me and the guy took apart the top cover of the FJ and this what we found.

1: The valve cover gasket was stuffed. Cracked in 7 places and whoever had previously tried to fix it had stuffed it full of silicone. So you guys were spot on with the leak, now I just have to see how much of the silicone is in the motor.

2: The guy who was helping me upon evaluating the condition of general parts said it looked as though the FJ had been standing for a REALLY long time before I got it.

3: The timing chain is stuffed, no make that fucked. Not stretched a little, just really really kaput.

4: We checked the compression of the cylinders. Sitting on the bike - left reads 70 psi
                                                                                              inner left reads 30 psi
                                                                                              inner right reads 20 psi
                                                                                              right reads 90 psi
The guy went on to say it looked as if I had been running on a portion of 2 cylinders since I basically got the bike, so who knows how long its had problems

5: We used what I think is called a feeler guage to measure clearance. On the port closest to the left, there was absolutely no clearance and on the port next to that there was quite a bit of clearance

From this the guy said that a valve had probably been sitting open and this could either lead to a bent,/ dropped/burnt valve

Next week we will go into the top half of the motor and actually check just to make sure. For now the guy says I definitely need a new timing chain and valve cover gasket
Life behind bars - is actually quite thrilling

fj11.5

hey jesse,  sounds like yours has gone out in sympathy with mine, burnt valve ,, hope you can get her sorted mate, , oh ps i found that clutch lever , if yours has a smallish spring behind it it should be it, may need your address again though (popcorn)
unless you ride bikes, I mean really ride bikes, then you just won't get it

84 Fj1100  effie , with mods
( 88 ) Fj 1200  fairly standard , + blue spots
84 Fj1100 absolutely stock standard, now more stock , fitted with Fj12 twin system , no rusted headers for this felicity jayne

andyb

If your compression is that crap, you will probably wet yourself riding it with a healthy motor for the first time.  I suggest doing strengthening excersise for your shoulder girdle muscles, as you will have your arms ripped out of their sockets when it runs properly!

FJTillDeath

LOL thanks Andy, I donno who actually remembers but I got on the FJ after riding my little 125 commuter bike, when I first got on it I thought wow its fast, but easy to ride, maybe now I see why it was sooooo easy from what I thought it would be...

Although In a way if I was actually riding a "2 cylinder" bike it would be good training for when I have the FJ completely up and running..like working my way up as they say
Life behind bars - is actually quite thrilling

racerrad8

My Q&A is in bold below.

Quote from: FJt!llD3@th on December 01, 2011, 12:16:50 AM
1: The valve cover gasket was stuffed. Cracked in 7 places and whoever had previously tried to fix it had stuffed it full of silicone. So you guys were spot on with the leak, now I just have to see how much of the silicone is in the motor.

1A) Easy fix, it need a new gasket, make sure you replace the eight grommets as well. You found one of your leaks...

2: The guy who was helping me upon evaluating the condition of general parts said it looked as though the FJ had been standing for a REALLY long time before I got it.

3: The timing chain is stuffed, no make that fucked. Not stretched a little, just really really kaput.

3A) What is wrong with it? There are usually only two things wrong with the chain; it is stretched or stretched until it is broken. If he is saying it is stretched because the cam timing is way off, who is to say someone did not install the cam(s) properly at some point? Please pass along some more detail and/or photos documenting the chain issue.

4: We checked the compression of the cylinders. Sitting on the bike - left reads 70 psi
                                                                                              inner left reads 30 psi
                                                                                              inner right reads 20 psi
                                                                                              right reads 90 psi
The guy went on to say it looked as if I had been running on a portion of 2 cylinders since I basically got the bike, so who knows how long its had problems

4A) See answer 5A.

5: We used what I think is called a feeler gauge to measure clearance. On the port closest to the left, there was absolutely no clearance and on the port next to that there was quite a bit of clearance

From this the guy said that a valve had probably been sitting open and this could either lead to a bent,/ dropped/burnt valve

5A) I would get the valves adjusted correctly, then run the bike for  a good run and the recheck your valve lash after it cools down. You might need to adjust the valves with no clearance a few times to get them in the range. Once you get the valves adjusted properly and any carbon on the valve face or seat cleaned off your compression numbers might be within range. I would take these steps prior to jumping into the engine. I recall another member removing his head after determining "burnt valves" and they were okay when it was disassembled.

Next week we will go into the top half of the motor and actually check just to make sure. For now the guy says I definitely need a new timing chain and valve cover gasket

For now I agree about the gasket & grommets, but I need you to show me about the T/C

My last word; I do not know your mechanic so I cannot speak to his qualifications. I hope you have faith in him as you have selected him to work on your bike. But, with that said, you need to be an educated consumer in dealing with any mechanic. You have posted here and with more information we can determine if you really need all of the repairs he is recommending or if some adjustments will resolve the issue. If you brought your bike to me as you have described, (absent the unknown T/C issue) I would adjust the valves install a new gasket and run it, followed by another check of the valves, adjustment and running. Then I would recheck the compression. If the valves are tight, the compression will be low.

Also, make sure the throttle plates are open when checking compression. If your carb sync is way off, those two really low cylinders might have the carbs closed completely and with no incoming air, there is no compression.

Randy - RPM
Randy - RPM

FJTillDeath

Thanks Randy, I appreciate the info

The guy I have selected as "my mechanic" is a guy in my motorcycle club who loves the FJ and used to own one many years ago, he has owned many of the older bikes. He is a qualified bike mechanic but he works at a car workshop. He isnt charging me at all for the work as he says he enjoys working on engines and would really like to help me get the FJ back up and running.

As for the Timing chain, I will get pictures of everything next week again when I see him(hes going on a rally today). But the timing chain is finished, super stretched to the point where its about to snap, its already hanging/ skipping a tooth on the rear gear, there is also a link that is rather damaged. I asked him if maybe it could still be used he said no way. I will try get more info and bring up the cam issue with him though

It wouldnt surprise me if the cams were not installed properly, I was told that the dealership I bought the bike from have made many stuff ups on the bikes people bring them, it really is a gamble to buy from them.

We are going to replace the gasket, and do the shimming/ valve clearances. I was just wanting to jump ino the engine as to ascertain everything that would need to be replaced and all I would need to save up for. If you agree with the mechanic in saying I should just get the top work done before jumping into the engine then I will have slighttly more peace in me. If it is just grommets, valve cover gasket and a chain that need to be replaced I may not have to wait too long to get the FJ up and running again. As it is I have to wait 3 months until I have cash available, or maybe my mom can help me out.

Lastly the dealer that sold the bike to me said they might have a timing chain in stock but needed a sample. They qouted me at 900ZAR, which I think is 110 US$. Is that reasonable? I havent seen the timing chain on your site..
Life behind bars - is actually quite thrilling


racerrad8

Don't forget, the engine must be completely torn down to replace the timing chain. After the rods are installed on the crank the T/C & starter drive chain are installed and then the crank is set into the case.

So, you are going to be doing a complete rebuild. Tear it all of the way down and look at everything. I have every engine part in stock with the exclusion of the new cases, barrels, cranks, heads and studs.

I can get everything for your 1100 with the exclusion of the pistons & piston rings.

I have the new undercut transmission in stock, and you might want to replace the starter drive with an XJR unit while you have it torn down.

Let me know what you need. It is much easier if you email me your list if you need something not listed on the website.

Randy - RPM
Randy - RPM

FJTillDeath

Thanks Randy, I will let you know, we are going into the heart of the beast today to see everything..

Apparently there is a guy who deals specifically with yamahas, mainly xjrs and things who said that he would redo everything in my top end, set the rings right, straighten valves etc -basically rebuild it properly for me all for 450zar - about 55 us dollars which I am told is peanuts compared to what these things normally cost to fix..

Though I will probably have to supply some of the parts like valve stem seals etc. I am gonna make a list of everything I will need, consumabls included.

I might be getting a xmas bonus so that might help a bit with things :good2:
Life behind bars - is actually quite thrilling