i like how you seem to ignore our advice and just post something vague. Anyways, from that picture how can you tell if chain slipped? turns and see if you can get them to look like this


if you can't, then you have a problem.

 

while you're at it, check the valve clearance. also, white build up may be a sign of a coolant leak.

 

I apologize if it seems that way. I usually work on my bike at a FOAF's shop with access to any tool I can think of, but my garage only has a set of sockets and various wrenches. I was saving money before continuing. I'm ordering a compression tester of my own now and I guess feeler or tappet gauges, I just pulled the valve cover off during a break today to see what it looks like/if anything looked strange. I've never adjusted motorcycle timing so never mind. I will update with more info. when I have it.

 

It's been awhile, sorry for such a long update. But I like to be thorough.

Hey guys! It's been just over 3 months since my last update on this post. Over the past 2 weeks I dove hard into the engine. I finally managed to dismount it after a few days lacking proper tools. And this evening I removed the valve cover, cam shafts & sprockets, and the head. Originally I was going to take it to a shop who agreed to diagnose it for $80. But a few days ago I emailed the mechanic again and his response changed my mind.. He told me that I "Definately slipped a tooth, which resulted in bent valves and messed up head. And I would have to pay the $80, plus $240 to R&R the head, plus $330 to service the valves, plus the cost of valves, gaskets, and anything else used." All based on a hunch. And I am not trying to pay $800 for something if I'm not positive it's broken. Info recap: My bike has a USB ignition key, it will not start without it, and will eventually shut off the fuel supply until the engine dies where it will then stay dead until the key is reinserted. My CCT had rattled loose on the highway, and on my return home I noticed a loud knocking noise at idle & when revviing. I noticed it when I was decelerating and at first thought it was my chain making the racket. Until now all evidence has pointed to bent valves due to a slipped timing tooth from loose CCT. Until I studied the engine and found that the cam chain sprockets were timed correctly, and the sprocket under the crankcase cover was aligned with the notch in the crank case. I was thrown at this point not knowing what could have happened. I pulled the head off and behold, the pistons looked fine albeit some normal carbon and a little surface rust over 3 mo. storage, and the valves appear fine (to me). definitely not the appearance of such a racket causing culprit. Going back to the CCT loosing it's tension I examined the guides. Every guide looked perfect with lots of life left, then I looked deep towards the bottom sprocket and saw a metal piece of the engine which looked like as if high speed chain had been lashing away at it. It was the uppermost crankcase bolt housing, which rests 1.5-2 inches in from the cam chain itself. Right now it's my no. 1 suspect for that awful noise. It didn't have a natural curve as if it was designed that way, it looked filed down. So I'm going to examine that closer. I feel silly tearing apart my entire engine and having to buy gaskets when I could have just re-tightened my CCT. But better safe than sorry! This is assuming this chain slapping was the cause. And based on the evidence and events leading to this I have a good feeling about either that, or knocking from a fuel/air ratio. Here's the events:
1) My FI light would always blink consistently. I didn't know that could mean any number of fuel/air sensor malfunctions.
2) My USB ignition key unknowingly fell out of it's port during the ride. Meaning the computer would begin it's anti-theft job and start cutting off the fuel.
3) Vibration from the high RPM ride on the highway, and a lack of threadlocker on the CCT nut caused the tension to loosen until the chain was so loose it slapped against the crankcase bolt housing. Thankfully not slipping a tooth.
4) The knock/racket was most noticeable when decelerating, or at idle. And it persisted when I was in neutral just using the starter. But when I turned the crank by hand there was nothing unusual, just compression and release. Although there was a small pshhh that I would hear each manual rotation that lasted ~5-10 if I stopped turning when I heard it, otherwise it would just release a quick pshh.
5) I remember hearing the knock during neutral using starter, ignition switch on, but USB key missing. And I remember hearing the knock EVERY turnover. It didn't sound isolated to one cylinder because it would have knocked every other compression and it was consistent. The knock occurred after I had shut it off and tried starting it again without the key. At that point the engine would not have allowed spark, so now I guess the detonation theory is ruled out?

I never got to do a compression test sadly. I would have had to rebuild a new USB key for it to even start The bike was disassembled to the point where checking out the inside was easier than buying a tester (I don't even have a spark plug socket), then building the key, reassembling the bike, and letting it run while hearing such a bad knock/racket.

Is there a chance it's still valves? If it isn't the cam chain slap, based on the info what else could it be? I understand this is an unusual case, that I know of no other F4i uses this USB type of key since I handmade it. And keys don't just fall out of keyholes causing a mid-ride anti-theft event. I plan on trying the solvent test for the valves to see if they seal properly. The camshafts looked perfect, the valves pretty good (nothing bent or visual to me), the pistons fine. It turned over by hand, as it should, just fine BUT only if I applied good pressure to the tensioner with my finger. Otherwise the chain would lift off the first half of the sprocket until it hit the top chain guide mid-sprocket. But with no manual pressure to the tensioner it would be jerky and hard, and a few times I thought I did slip a tooth by not applying pressure, but I checked each time and both sprockets and the crank sprocket still were correct. Could this rise and forced seating of the cam chain have caused the back of the tensioner to slap against the head housing? I'm trying to think of all possibilities and get input on what the smartest next move would be. Could I reattach the starter and turn it over with no head if I oiled it, to check for noise? I do need to check the valve clearance but it didn't seem to jump at me from looking at it to be the cause of a loud knock. I apologize for the long post, I just wanted to be thorough.

I'm linking a photobucket folder including all of the pics I took after taking off the head. Look through them if you have experience and think could spot something I'd miss. This is my first 4-cycle to take apart, so I'm not used to much of this yet.
Thank you everyone for trying to help, I don't have much money because of school and trying to help my gf save for a car downpayment. It's very slow and frustrating doing everything by myself with no experience besides a 2-cycle dirtbike rebuild. To be honest it scares me knowing it could be anything from rod knock, to valves I can't properly fix. When I rebuilt by 2-cycle RM-125 I was very proud, it was bought for $700 and had such bad compression it required a rollstart. It was like new when I finished, and then a rod bearing shot 2 weeks later during a ride. It seized up my engine, scored the cylinders, destroyed the pistons, head, and ground metal in my trans. One of the worst days I can think of. So you can understand why I'm thorough right now.

Here are the pictures.
1_29_13 Bike Update Photos by jacksla3 | Photobucket

 

I watched just about every YouTube video I could find on CCT noises, spun rod bearings, valve noises. I think I was overly optimistic about the CCT alone causing such a persistent LOUD tapping/knocking. I think when I first looked at the valves I saw one set dropping lower than it should. That may be hitting a piston. Maybe it did jump a tooth, and even though it didn't hurt the piston it might have damaged some valve guides or assemblys. Tomorrow I'll spray some solvent in the valves and check their seals. I think at least one will leak. And who knows if more will fail in the future. I'm pretty bummed out about the whole thing. The head gasket price alone is enough to make me cry just thinking about a valve job on my broke budget. I don't think it's a spun rod bearing since it was so sudden. Any further advice is appreciated.

-Jack

 

Ok... you are in a bit of a mess .... the fastest way to find out what is going on is drop your oil pan ... look for brass/gold colored shavings in the pan..

look at the oil pick up see if it is clogged up.. take a flash light look up at the piston skirting look for fractures.... with a bike properly in time with a hard knock sound like a rod knock... but i always expect the worst...

rod knock can come on extremely sudden....

i had a spun bearing and didn't hear it ,couldn't even feel it except under certain conditions and it was right before failure.... when the oil gets hot and the engine moves more freely....

good luck

 

Okay, thanks for the reply! I'll try that next.

Today I did a seal test on the valves and only one exhaust valve leaked, on the far right cylinder from drivers position.

 

may have missed it .. did you check and verify clearances??? clearances can get tighter over time.. causing piston slap... could account for leak down just a thought i would put out there

did you leak down with the cams out or in???

exhaust will have a larger amount of carbon build up than intake... before calling the valve burnt go ahead and compress the valve open and clean with carbon removal spray or ATF and perform a leak down again to verify that it wasn't just build up...

after valve cleaning you will need to verify clearances again cause they will change....

if you are going to need to scrub use a gray scuff pad not brown it's finer and will not remove valve or head material and will ensure proper re-seating and wont risk harsh scratches into the valve or head.

 

Did u check any of the cylinders if it had excessive fuel, at the time u first took your engine apart? Hydro-lock caused my engine to knock before, but nothing damaged. Had to let it sit for awhile, sometimes up to 3 days before the engine would crank over. Bad FPR was the culprit. I replaced it and now everything been fine for 7,000 miles already.
FPR can have too much build-ups causing some cylinders to flood. You did mention revving your engine too. And hand crank pshhh sound, did it sound like liquid squirting out?
Anyways, I'm not saying it's the problem, but it's something to look into.

 

I didn't think about that. I checked the valve seals with the cam's already out. I don't have any measuring tools like tappets (i think) to really check the clearances yet. I'll have to order those, although I think they are fairly inexpensive.