'06 rebuild, am I in trouble if my timing chain guide melted?

[dawe5485]

This is my first rebuild on an '06.  Here is what im looking at, looks like its burning oil?  I scratched the top of the piston with my finernail, its just a layer of gunk.  Was planning on just rebuilding the top end but am I in need of more work to the valves, and figuring out what happened to my chain guide?

[Jeff@bigborethumpers]

Was the bike used when you got it?

[Diggla117]

Piston-your gonna need to replace that anyways 13.5 cp pistons are nice

Head- have you had to shim them? They look a little recessed... IF you Havnt had to shim them and clearances are still in spec then I'd clean it up real good and let it ride.

Cylinder- it needs to be measure to make sure the cylinder is completely round and not oval in ANY spot. A good machine shop can help with this.

Cam chain guide- looks like you had a little fire there bud or that thing got extremely hot. Def replace and by the looks of that you def need to check your crank and go ahead and rebuild/replace if rod or piston ring clearance is out at all and def go ahead and replace your crank bearings along with cam chain(oem) and after market manual cam chain tensioner... Boom

Oh and a service manual and torque wrench are a must.

[dawe5485]

Piston-your gonna need to replace that anyways 13.5 cp pistons are nice

Head- have you had to shim them? They look a little recessed... IF you Havnt had to shim them and clearances are still in spec then I'd clean it up real good and let it ride.

Cylinder- it needs to be measure to make sure the cylinder is completely round and not oval in ANY spot. A good machine shop can help with this.

Cam chain guide- looks like you had a little fire there bud or that thing got extremely hot. Def replace and by the looks of that you def need to check your crank and go ahead and rebuild/replace if rod or piston ring clearance is out at all and def go ahead and replace your crank bearings along with cam chain(oem) and after market manual cam chain tensioner... Boom

Oh and a service manual and torque wrench are a must.

Thanks, the valves where in spec when i removed it.  Do you run a manual chain tensioner, is the oem not very good?  Really trying to avoid messing with the bottom end, if possible just concerned if this is a prelude to something worse.

[Diggla117]

Thanks, the valves where in spec when i removed it. Do you run a manual chain tensioner, is the oem not very good? Really trying to avoid messing with the bottom end, if possible just concerned if this is a prelude to something worse.

Hmmm how do I put this..

First off I bought a extremely low hour 06 last year and completely rebuilt it. I completely rebuilt it because personally I have no idea the real hours on the motor. Extremely low hour, great shape bike. With that being said it's a 8 year old bike at the point.. That motor, that piston, that rod, that crank.. Turns up to eleven THOUSAND revolutions per minute from the factory. You found a odd piece burnt that came out of the bottom end and you don't even want to open it up and inspect it before you slap it all back together and throw your legs and your junk around it and see how fast you can get it to turn up?.. You get where I'm going with this? While it might seem like I'm jumping your case I'm really trying to put it in prospective. The smallest flaw can turn that motor into a grenade... It's your body tho. Hope this helps

[Diggla117]

The eom tensioners are known to randomly fail. The very least id replace the factory tensioner but really I would rather spend that 40 on a manual after market tensioner and never have to worry about setting it again, replacing it or it ever failing.

[dawe5485]

Yeah I understand where you are coming from, but i have never opened up the bottom end on a bike before, so its going to take me quite a bit of time.  Also if i tore into i would have no idea what i'd be looking for that might have caused the guide to melt.  If i where racing this I would be more concerned, but I have it set up for supermoto and i hardly redline this motor.  I searched the forums and no one else has posted about their guide melting which makes me think the guy before me might have ran it hot and low on oil.

[Diggla117]

Grab a SERVICE MANUAL and get to studying... It's all In there. You'll have to buy a few tools and case seals but it's really not bad. You just have to take your time and study.. Plus that's what this site is for.. People helping people do it their self and save cash, among a few other things. Either do it now or keep it in the back of your mind and just ride until it reminds you of what you should have done.. Either way that's motors most likely way past due for having it done and it'll cost you more in the long run. But yeah Goodluck

[tonkaman]

Don't let fear stop you from getting to know your bike better. Absolutely buy a service manual whether you decide to split the bottom end or not it is absolutely your best friend. Once you have one you will see that it's an easy task that takes a small amount of tools and nice flat workbench to layout parts

[dawe5485]

Grab a SERVICE MANUAL and get to studying... It's all In there. You'll have to buy a few tools and case seals but it's really not bad. You just have to take your time and study.. Plus that's what this site is for.. People helping people do it their self and save cash, among a few other things. Either do it now or keep it in the back of your mind and just ride until it reminds you of what you should have done.. Either way that's motors most likely way past due for having it done and it'll cost you more in the long run. But yeah Goodluck

What is "it"? What is my objective to opening the bottom end, replacing the crank bearings, or am i just opening it up to troubleshoot?  Forgive my ignorance i'm just not sure what catastrophic issue is staring me in the face.

[brucegregory]

you can check the crankshaft without splitting the cases, there is a service limit for rod side clearance, also pull the oil filter out and see what is in it usually copper flakes mean bottom crank bearing.pull the left side cover and move the crank up and down to see how much play is in the main bearings, i would pull the fltwheel and put a cam chain and while you are there clean the oil pickup screen. i had both of my 08 450's lock up on me and both times it was the crank.it did not cause any other issues, another thing to look at is the oil in both sides, left side is motor oil and right side tranny oil. make sure there is no water in them .the seal crank likes to fail causing the transfer of fluids, cc the amount on both they should both be around 680 cc but go back with 700cc in each

[brucegregory]

i can give you any service limits you might need. but you should buy the honda OEM service manual PDF instant download is 6 dollars online or paper back is about 30 on ebay. myself i like paper back. but you can always print the pdf,

[Shawn_Mc]

The only reason that tensioner would melt is if the bike was severly over heated. The OEM tensioner isnt capable of doing that. A manual tensioner set way way too tight could have though.

 

The engine was oiling significantly, thats what those deposits are in the combustion chamber.

 

At a minimum, you should check the intake valve guides and replace the seals. The OEM seals arent capable of withstanding the kind of heat it took to cook that chain guide.

 

Id also look at the big end of the rod in addition to the little end for bluing. Getting that hot is tough to do unless complete irresponsiblity was at fault or somebody was forced to ride back to the truck for 15-20 miles with no coolant or something.

[dawe5485]

Oil filter is clean, and clearance between the rod and crankshaft is .35mm, which is in the standard range.  There is some slight play with the rod from side to side, and discoloration on the rod and inside the small end of the rod.  Pulled the left case, no play in the flywheel.  Looking at the chain guide and where it melted, it fits right next to the flywheel.  Its a larger flywheel(21oz) to run the lights, could this generate the heat to melt the guide?

Edited May 14, 2014 by dawe5485

[Shawn_Mc]

Oil filter is clean, and clearance between the rod and crankshaft is .35mm, which is in the standard range.  There is some slight play with the rod from side to side, and discoloration on the rod and inside the small end of the rod.  Pulled the left case, no play in the flywheel.  Looking at the chain guide and where it melted, it fits right next to the flywheel.  Its a larger flywheel(21oz) to run the lights, could this generate the heat to melt the guide?

 

Ive got no idea how a flywheel could generate heat unless it  was rubbing something. And thats what the guide looks like, now that youve added that info. The Stator could get that hot...that would make sense.

 

Contact the company that built the Stator. Most of those came from Trial tech. Id ask if this is a known issue. If its got a bad winding, and the flywheel is still bypassing the pole, it could create a shit ton of heat. Or a regulator rectifier thats maybe not working correctly...

[dawe5485]

The only reason that tensioner would melt is if the bike was severly over heated. The OEM tensioner isnt capable of doing that. A manual tensioner set way way too tight could have though.

 

The engine was oiling significantly, thats what those deposits are in the combustion chamber.

 

At a minimum, you should check the intake valve guides and replace the seals. The OEM seals arent capable of withstanding the kind of heat it took to cook that chain guide.

 

Id also look at the big end of the rod in addition to the little end for bluing. Getting that hot is tough to do unless complete irresponsiblity was at fault or somebody was forced to ride back to the truck for 15-20 miles with no coolant or something.

Does the picture i posted of the rod represent the bluing you are referring to?  Also were you suggesting that the oil deposits were potentially coming from the intake valve seals?  If so are there any special tools i will need to replace these seals?

Edited May 19, 2014 by dawe5485

[Shawn_Mc]

Does the picture i posted of the rod represent the bluing you are referring to?  Also were you suggesting that the oil deposits were potentially coming from the intake valve seals?  If so are there any special tools i will need to replace these seals?

 

No, it really doesnt. That burned cam chain guide bugs me. Its not even the tensioner side...it just sits there. and it looks like its burned on the inside side, thats up against the main bearing in the case. Its hard to imagine the circumstances that would allow the cases to get that hot and not eat the crank for lunch.

 

Starting from the begining, Id guess this is a second hand bike, its been apart before, and the reason it was apart was because somebody ran it out of oil. The guide was good enough to use and sell after they got it back together.