CB650C Project from P. I. Needs help of a brethren..

[Bongskit]

LMFAO.

[Volker_P]

What are the odds of damages because of the intermittent oil light and those bits of pieces I found at the bottom?

If at all, remote identification would require sharp pictures.

I was thinking that I should replace all the cam tensioner and guide assembly for the meantime and see if that fixes everything.

Nice optimism. Keep it, but don't apply it to this engine!
BTW, both parts are discontinued at Honda.

Is it really suggested that I tear apart the case and inspect everything?

This is a high rpm engine so the answer is yes.
If you are lucky, only the tensioner/guide has gone and some alumina has been grinded out there.
However also bearings might be already affected. Have a look into the oil gallery beneath the crankshaft for further metal stuff.

From my experience with engines with oil pans like that, many parts are still intact but also some hidden parts may need replacement. And especially after filter failure everything needs to be cleaned! Including e.g. crankshaft oil bores and things you don't think of now for sure.
I would inspect the calibrated oil nozzles in the camshaft oil gallery at the bottom gasket level and the crankshaft bearings in any case. This already implies a complete disassemble.

Sorry.

So no time to order any parts yet, but check out what you need and if it is worth it (or even possible due to parts unavailability) to rebuild this engine or better get another one.

I will gladly do that in no time just to get her mobile again. I want to ride her every weekend and some other work days. Nothing compares to riding the bike instead of a cage.

You will need some patience now to avoid a never ending story of failures and work.
Bad parts can kill good parts. And they will!

[Bongskit]

Is it really suggested that I tear apart the case and inspect everything?

This is a high rpm engine so the answer is yes.
If you are lucky, only the tensioner/guide has gone and some alumina has been grinded out there.
However also bearings might be already affected. Have a look into the oil gallery beneath the crankshaft for further metal stuff.

From my experience with engines with oil pans like that, many parts are still intact but also some hidden parts may need replacement. And especially after filter failure everything needs to be cleaned! Including e.g. crankshaft oil bores and things you don't think of now for sure.
I would inspect the calibrated oil nozzles in the camshaft oil gallery at the bottom gasket level and the crankshaft bearings in any case. This already implies a complete disassemble.

Sorry.

So no time to order any parts yet, but check out what you need and if it is worth it (or even possible due to parts unavailability) to rebuild this engine or better get another one.

You will need some patience now to avoid a never ending story of failures and work.
Bad parts can kill good parts. And they will!

Bob!!!! You got my back alright??!??!

I will keep this thread updated with nice pictures during tear down and rebuild. I need everyone's eyes and expertise.

[usbear]

I am checking my shipping options at forwarding office this morning for you.

"Wild Chili"

will live again!

[Bongskit]

Thats my man!

I think I know now what kind of decals to put on those 2 side covers. Thanks for the idea Bob!

Patiently waiting....

[Bongskit]

so i tore down the cam cover and took pictures. so far i have not seen anything in distress besides plenty of copper washer are missing and 1 bolt was replaced by an allen cap head bolt. 2 of the bolt holes shows signs of stripped threads. removed all the bolts according to pattern. I have a complete set of spare rocker arms, rockers, covers, etc. anything in particular you wanted to see in clear detail like if it was you that are inspecting? tomorrow i will bring down the cylinder head. i am taking it a day at a time. nice and slow.

[Volker_P]

Nothing dramatic so far.
Some of these rocker arms seem to have changed color where they run on the camshaft.
Means they were hot, probably due to a shortage of oil.
So check out these surfaces as well as the cam lobes and the camshaft bearings in the head.
Are there metal filings in the oil pool beneath the camshaft, too?

[Bongskit]

Volker: none but i will double check and take a deep inspection for sure. good point. I will update soon.

[Bongskit]

so took the next phase and remove the cylinder head and jugs. like I promised and Volker's request for sharp pictures , i brought out my dslr to snap these photos. im going to bring up first the damages.

cam chain guide:







cam chain tensioner is still holding up but not for long and replacement should be in order






the damage done in the crankcase due to rubbing cam chain. the encircled main bolt hole thread are already stripped. there's no effort when i removed the bolt in there. i wonder why no oil seeping in that adjacent head area. for sure i have low compression reading in that #2 cylinder would you agree?









this is the only cylinder that got me a bit worried when i saw it. but when i felt it with my finger, it is so smooth.












i have not seen a single spec of alumina in the cylinder head oil pool. saved by the filter?




here are more photos.















I found 3 stripped threads in the cam shaft cover to cylinder head and definitely done by the previous owner's mechanic. Can I just bring it to a machine shop and have it re-threaded one size bigger? or helicoil is the best way to fix it? That includes one of the main cylinder bolt i have shown above.

Do you have other request for pictures that you would like to see and assess? Let me know your suggestions what else I should take a closer second look.

[usbear]

1) make some plastic or small wood strips and put under piston skirts to hold pistons stable and remove wrist pin clip and wrist pins then pistons. ( Careful not to break them) Mark location of pistons for future inspection. And safely Store them. Scribe a mark in top of piston is ok but not deep , just carbon scratch. Yes, they may come in handy later.
2) Not surprised by Cyl wall marks or bolt threads.
3) Keep on keeping on to see total analysis.
4) Good work so far. Looks like PO parked it for known reasons.

Well another day, to see total picture and then make decisions sir.
Good progress so far.
Like Volker said: Check it out completely first then decide on repair path.
Bob!

[cb650]

I was given a parts bike once from a guy I raced with who ran a repair shop. Started and ran but the cam chain had sawed a hole in the cylinders.

[Volker_P]

Thanks for the pictures, all that looks not that bad.

Camshaft bearings look fine and even the tensioner may be reused, but of course not the front chain guide.

I would replace the cam chain in any case as it certainly saw unusual loads.

So all the metal might just be alumina from the block. Consequences of riding with an obviously misaligned tensioner for some time.
But you have to get it out completely out of every corner so it won't collect in some oil channel and cause seizure.
Don't forget to check the primary chain nozzle, it is close to the oil pump even still in front of the filter. Quite sure it is plugged now.

For the head cover bolts, helicoil is the first choice as material around is weak with regard to larger bolts.

[MiGhost]

The problem has deffinately been identified. The PO probably did not get the front chain guide properly located when the engine was worked on.

The good news! Everything that i see is repairable. "Wild Chili" will ride again!!

Cylinder, and Case gouges: Sand these down to smooth off the rough edges. You do not want any of that stuff breaking off, and falling into the engine when you have it rebuilt.
Front chain guide: Have a machinist turn some new bronze bushings to replace the plastic bushings on the locating pins. You will want an interference fit on the bushings. The guide material looks fine for reuse.
Cam chain: I would replace this due to the fact that it most likely has aluminum fragments in it from the contact with the case/cylinder.
Chain tensioner: This is reuseable. New replacement is avavilable from honda.
Cylinder sleeves: These look good. Factory cross hatch still visible. Check piston, and ring clearances. A light honing to remove glazing wiil alow the rings to seat properly.
Oil pump: I would find a good used low mileage replacement pump. It is Highly possible that the pump rotors/body could have been damaged by the aluminum bits going through it. This could be the cause of the oil light comming on.
Starter Clutch: While you have everything apart. I would replace the springs, and rollers in the starter clutch. These are wear items, and could go bad from have been left sitting.
Standard rebuild process: Replace wristpin clips, clean everything to make sure all aluminum bits are removed. Repair/replace worn/damaged pieces.

Pay attention to the details, and you will get it up and running again.

Ghost

[Volker_P]

The problem has deffinately been identified. The PO probably did not get the front chain guide properly located when the engine was worked on.

Moreover he misaligned the tensioner. This means a loose chain that may have smashed the front guide. Maybe both.

Front chain guide: ... The guide material looks fine for reuse.

No! I would think there should be side rims to keep the chain away from the case as for the tensioner itself. Looks like they are completely grinded away to black plastic stuff in the oil pan.

Oil pump: I would find a good used low mileage replacement pump. It is Highly possible that the pump rotors/body could have been damaged by the aluminum bits going through it. This could be the cause of the oil light comming on.

I agree that a good replacement would be a fine and safe solution.
However aluminum is not that tough, so a look inside and a measurement of clearances may decide if it may still be all right.

Starter Clutch: While you have everything apart. I would replace the springs, and rollers in the starter clutch. These are wear items, and could go bad from have been left sitting.

Good point!

[MiGhost]

Front chain guide: ... The guide material looks fine for reuse.

No! I would think there should be side rims to keep the chain away from the case as for the tensioner itself. Looks like they are completely grinded away to black plastic stuff in the oil pan.

Volker
You are correct. As can be seen in the pics on M_Hills post here.
viewtopic.php?f=2&t=6933&start=45

Ghost