Possible bent cam? Ways to check?

Ok, thanks! I'm definitely not trying to argue, but I didn't understand and my default position is that I'm being a dummy.

 

I can't agree with that........if that were the case then it would go slack like that for all 8 of the valves. The lifter follows the cam lobe.....there is a ramp up and a ramp down. The valves don't snap shut. They slide open and slide shut.

 

i'm glad somebody pays attention. next time you have a cam chain off try it. i found it by spinning the cam to get the sprocket bolts lined-up.
anytime a valve is closing, it's pushing the cam, most of the time the lifters don't touch the cam. so if a lifter pushes on the top close part of the cam, it has enough leverage to push the cam until another lobe goes through it's clearance and touches.
so how's that work with four valves...? i don't know but it does, mine did.
we have to agree it's not jumping a tooth and it's not the sprocket bolts hitting

 

What's that thing that's rubbing on the top of the crankshaft when the crank is being turned?
It kind of looks like a guide of some sort, but there is no guide in that position.

 

Wow I never noticed that before! I was so focused on the cog teeth and the chain! But I'm sure that's the one guide that has recently been removed/ replaced I'll try to find a pic

 

This should be what you were seeing

 

I don't like how the chain is so much to one side.

Also, what quality chain did you buy, and where did you get it

 

Almost looks like there are two of the same guides...

Also, is it possible that part of a lower guide has broken off!?! I can't see well enough

Or was one installed wrong?

 

That's a question better suited for @TheCrazyGnat as he has the guides at his house.

 

K&L Dec-97 1993-2001 Suzuki Gs500Ep~Ey/K1 Cam Chain 219H X 120 https://www.amazon.com/dp/B0055DQISU?ref=yo_pop_ma_swf this is the chain I got

 

The guide on the left is the same as the left, I ordered replacements, the one on the right is what was on and bent

 

https://www.ebay.com/itm/Endoscope-5-5mm-Inspection-Camera-For-Android-PC-Laptop-Borescope-Waterproof-LED/272969087508?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649


right click and open in new tab this is a handy tool

 

Already have one of those, they don't work very well...

 

mine does I hook it to my laptop

 

I use mine on my phone, i just get frozen images if I get anything at all

 

The lower part of the front guide seats in the case below and in-front-of the chain. Same for the rear guide. Neither guide should ever touch the crankshaft, and both guide the outside of the chain to prevent it from hitting the cases and cam-chain well. The only guide that runs inside of the chain is the top guide.

In the video it looks like the guide is resting on the crank, and sitting on the inside run of the chain. That would cause the chain to bind, and then release.
https://www.yamahapartsnation.com/oemparts/a/yam/500421c6f8700209bc7873b8/camshaft-chain

 

Saw those advertised in the " you just GOTTA have this" stuff on facebook... those kind of ads all say "look at me -- don't waste your money here" to me

 

Huh?

 

I see crap like that on Facebook ads all the time. It's all junk

 

For my chain? I found that after over an hour of trying to find an aftermarket chain that was over priced....

 

The guides that were in there were the correct guides. The front guide that was all buffered up had to have been installed wrong, or it was severely mangled before installation and they thought it was good enough. I haven't been able to get the rear guide out yet, it is in there pretty good. I can tell it is the correct style (it has that second curved metal piece).

It wasn't on the inside of the chain, the guide was located in its slot in the head.

 

No!.....the 5mm camera that doesn't work

 

I think he is talking about the 6$ bore scope

 

Oh! Bahaha forgot we even talked about that! Yeah I forget what mine cost but worked for like a week and died lol

 

1. The rear guide is held in by a special bolt. It's just below the cam chain tensoner. There is a locknut below it. Removal is easy. Installation requires a simple procedure where you tighten the bolt until it lightly touches the tensioner, and then hold the bolt in place with the locknut.
2. Then what is that in the video that's rubbing on the crankshaft? Nothing should be in that position.

 

Good question...... We will have to look into that further

 

Where can I find an engine diagram?

 

www.partzilla.com

this is link you want
https://www.partzilla.com/catalog/yamaha/motorcycle/1981/xj650-xj650h/camshaft-chain




www.yamahapartsnation.com

 

I can't figure out what that piece is...

 

those are the parts to install chain guide the long bolt holds rear guide in place

 

i think if you get guides and a tensioner in it your problem might go away by itself

 

I mean the piece in the video that's rubbing on the gear.....I can't figure out what it is

 

I'm sorry, I watched the video three times and I can't seem to see what everyone else is. I see the chain starting to go slack and sort of folding in on itself... Are you seeing something to the side?

 

Watch the top of the screen as the teeth come up, I'll send you a screenshot to show you where to look, took me a few times to spot it too

 

Ok, I think I see it. What it looks like to me is that only the top part of the front cam chain was located correctly and was just resting on the cam chain. So when the chain was getting a little slack, the guide was pushing the chain towards the crank. I imagine that is how the guide got so messed up.

 

After watching again at 2:10-2:20 on the video you can see it's the chain, the guide was probably bent when the chain snapped in 2016 and the shop left it like that

 

Facepalm.............

 

Wouldn't surprise me one bit... Who knows what else is messed up

 

Well.... @crazygnat and I have identified the problem....not 1, not 2, but 3 THREE bent valves!!!!!! AcordAcco to the shop there was only one bent valve and they fixed it.....if I put on here how I actually feel about this I'd probably get banned from this site! I've got three valves ordered on next day delivery in hopes that they arrive in time so I can get them lapped and back to crazygnat to get them installed so I can make it to the carb clinic!

 

Is this where I say "I told ya so"? Lol

 

I think you already did once today but if you must! I just hope we can get everything done in time! If it starts looking like my bike won't be done in time we might have to switch thing up crazygnat's wife's bike so I can ride that! Lmao! Hard to say at this point...

 

Do whatcha need to do--

 

What can I use to remove heavy carbon build up when carb/ brake cleaner ain't working?

 

soak with atf/acetone mix

 

BG products makes an air intake cleaner that works extremely well at removing carbon deposits. Have it at my shop. Only issue is it has to come from a distributor or shop that carries their products. Food for thought, was the first thing that came to my mind. I'm sure there's other products that are cheaper and more readily available

 

i had the heads off a 289 once and scrubbed the chambers with dish soap and water rinsed and covered then with a wet rag, next morning the carbon came out with a garden hose.
that being said, if you take that carbon out you will lower the compression ratio

 

And follow up with a medium stiffness brass wire brush.

 

I really don't know anything about compression so would that be a good this to lower it or bad?

 

I was using a "heavy duty" grill cleaner but notice it said don't use on aluminum so I rinsed it quick, but it did seem to be working! Lol