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Author Topic: Engine trouble (from the main boards)  (Read 7175 times)
knowsnothing
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« on: December 08, 2010, 01:15:42 PM »

Some of you know this but eh

Bike: 

K8 with 30,000+ miles on it. 




Background: 

I purchased the bike about a year and a half ago.  It is my first bike purchase ever and it was running when i got.  I definitly paid too much for it (blame it on naivety) and the PO i got it from didn't know the history of the bike.  However, it looks like everything has been gone through by someone (i will get back to that later) at least once.  It was in pretty rough cosmetic shape so I decided to tear it down and build it back up.  It was also my first venture into any type of mechanics so it was a learning experience if nothing else.  I ended up picking up another K8 in better shape for a 3rd of the price and got side tracked.  That bike is now my running beater bike so I am back to working on the 1st one.  From what i found while tearing it down, i don't trust any of the previous work so I have decided to take at least the top end off and see what i see.... I am glad i did.....

Current:

First off, please admire these fasteners -





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knowsnothing
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« Reply #1 on: December 08, 2010, 01:16:13 PM »

I took the cover off and this is what I found -









As you can see, there are pretty significant gouges from the chain as well as 2 large holes.  In the last picture (i know its a little blurry sorry) you can see that the chain is also eating a little of the head on the right.  I am pretty sure the holes aren't supposed to be there, but i could be wrong  Tongue  Is this cover just scrap now?  Or can i repair it?  Or does it not matter?
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knowsnothing
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« Reply #2 on: December 08, 2010, 01:16:54 PM »

After seeing the that damage i dropped the oil pan and was surprised to see very little shavings.  I checked them with a magnate and they did not stick so i am guessing its aluminum.  Due to the lack of serious metal fragments, the majority of the damage must have happened previously.  I also noticed that one of the long middle bolts was missing from the rocker shaft (i think that's the right term) and that the whole cam looked a little cockeyed.  It looks like the cam is favoring the right side.  Could the missing bolt be what is causing the gouging??  A vibration effect?

Shavings



Missing bolt



Slanted?

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knowsnothing
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« Reply #3 on: December 08, 2010, 01:17:25 PM »

Lastly -

Another scary thing is that some of the other nuts were loose to the point were i could spin them with my fingers.  I guess this too maybe be causing the issue.  I am currently stuck.  I can't get one of the camshaft bearing bolts loose.  It is too tight to get a socket on and a PO gummed it up a bit.  I made it worse trying to get it loose with a wrench. Anyone have any tips for this.  I tightened the nut next to it in hope of taking some pressure off of the stuck one, but it didn't work.  Do I drill the head of it off in a worse case scenario?  I was worried about the shavings getting everywhere if i did that.  Again, thanks for your time, I am currently in over my head   Wink Cheesy

Stubborn one



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knowsnothing
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« Reply #4 on: December 08, 2010, 01:18:46 PM »

So much for an easy overhaul   Cry Cry Cry Angry Angry Angry
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frostypuck
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« Reply #5 on: December 08, 2010, 01:47:36 PM »

Thats a lot to digest.
As for the rounded out bolt, I'd just snap the head off, remove the holder, and turn the remainder of the bolt out buy hand (vise-grips or the like)
The first pic clearly showed that the cam chain is wonky. Tensioner will have to be replaced at the minimum. The loose bolts probably contributed to the wandering chain.
Those acorn bolts were a kit, I've seen them on a couple other motors.
I'd venture a guess that that motor threw the timing chain at some point. You'd see a lot of wear on the existing chain if it had been rubbing, even steel vs. aluminum.
You've got a runner, maybe plan on a complete tear down, you may find damaged valves/ piston in there, too. It was running when you got it? Did it sound right?
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Alan F.
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« Reply #6 on: December 08, 2010, 02:00:28 PM »

I can try to repair that cover if you'd like, and I'll bring you my valve spring compressor thursday night too.
Alan
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knowsnothing
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« Reply #7 on: December 08, 2010, 02:18:47 PM »

Sorry Chris for the epic start   Wink  Yeah the chain looked pretty good from what i can tell so its curious to whats going on.  I guess i have all winter and then some to figure it out.

To your question, back when i bought it, i literally had 0 experience with anything soch4 let alone motorcycle.  The PO i bought it from kick started it, took off down the street (no helmet, a NH guy of course) and came back.  When i got it home my buddy kicked it again and took it down the block, so all in all i saw it run for about 10 mins and my ear was far from the fine-tuned diagnostic tool it is today  Tongue.  So, i have no idea if it sounded weird back then.

Alan, I was planning on saving my pennies and giving the head to Mr Reick to do some magic on.  But if you think i will need the spring compressor, i will gladly take it from you  Grin
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Alan F.
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« Reply #8 on: December 08, 2010, 02:36:04 PM »

I was planning on saving my pennies and giving the head to Mr Reick to do some magic on.  But if you think i will need the spring compressor, i will gladly take it from you  Grin

You'd only need it if you chose to remove the valves, I can leave it home if you won't need it.
Alan
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andy750
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« Reply #9 on: December 08, 2010, 03:51:09 PM »

Wow Treeve! That was quite the post!

Ok listen carefully now and Ill give you some advice....get a boat...any boat...and load the engine and a bottle of beer into the boat. Row the boat about 0.5 miles offshore...open the beer...and say "Cheers Honda"...and then very carefully push the engine over the side of the boat. Finish the beer musing all the while about how much money you just saved.

Row back to shore and go take your "beater" bike for a ride. Happy times ahead Wink

cheers
Andy

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knowsnothing
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« Reply #10 on: December 08, 2010, 05:11:03 PM »

Hahaha, thanks Andy.   This may become the parts bike after all!  To think this was supposed to be the "good" one that i was going to make fast.  The one i paid $400 more dollars for  Shocked Shocked  Though it does make a nice basement ornament  and adds a nice oily scent as well.     

I was planning on dropping some money in to this engine (836, mreick head, new cam) but it is looking less and less likely.  Stupid lemon engine..... Angry Angry
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« Reply #11 on: December 09, 2010, 12:17:23 AM »

Hey Treeve,

I think I have an extra cam cover and  fasteners for the cam towers that I'll bring over for you tomorrow eve. Listen, it's very common to find wear in the cam tunnel. (I think it's really a good idea to be diligent about adjusting the tensioner, perhaps manually preloading it is best if you're not hamfisted.)  Although I can't really tell from the photos, if the damage to the cover was caused by a chain that let go, it would be interesting to see if the tensioner was replaced when the chain was. Personally, I'd see if you can't center and reseat the cam, as long as the cam and bearings are in decent shape, and and see if you can get it running easily and cheaply.  If not, you can always tear it down at that time. Just my $.002, Chris is really pretty authoritative and knows a lot more than me.

See you tomorrow,
Ben
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knowsnothing
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« Reply #12 on: December 09, 2010, 02:06:29 AM »

Ben, that would be awesome of you Cheesy Cheesy

Well,the lady was out to dinner with some friends so I had 3 hours of uninterrupted time.  So i did what any decent guy would do, I went down to the basement and got oily....   (Ben, this all happened before i read your post, so the engine is half apart and your wish is my command)






They look pretty new to me.  I am guessing they were replaced with the chain like you suspected.  I really don't know what I am looking at when it comes to cam damage.  I have seen others post pics and have been unable to distinguish damage.  I am thinking i may bring it along with me tomorrow so everyone can take a look and let me know if it is junked.  Here are a couple pictures of the cam





« Last Edit: December 09, 2010, 02:14:33 AM by knowsnothing » Logged

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knowsnothing
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« Reply #13 on: December 09, 2010, 02:11:38 AM »

Also if anyone is curious (which i know you are  Tongue) this is what everything else looked like.  There does seem to be some piston damage from the exhaust valves hitting.  I am not 100% positive on this, but the indents are not symmetrical from piston to piston and just look wrong.

Valves






Pistons with love taps







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andy750
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« Reply #14 on: December 09, 2010, 08:27:34 AM »

Hi Treeve

I also have another cam cover you are welcome to - in fact I have 2 spares Wink.

A cam chain mashing against the cylinder block is nothing new - I have scores on the sides of mine on the K2 from a loose cam chain so dont worry about that. Look at the cylinder walls and see if there is any scoring. If not you are good to go and if getting an 836 kit then will be bored out anyway. Same goes for pistons, valves, rocker arms (inspect the pads on those), valve guides, valve seals, cam chain will all likely need replacing. Assume also a valve job on the head that goes with the porting and heavy duty studs.

The cost of the above in parts alone is a +$1000. Then factor in the labour costs (of course you can do reassembly yourself if feeling confident). If I were you Id budget $1500 - $2000 for a 836cc engine (leaning towards the $2000 more Wink).

See you later,
Andy

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