I see a broken thermostat. That thing should be right down the center.

IF you have coolant in the exhaust, you are correct. Screwed, blued and tatooed. Sorry.


A moment of silence for your engine.........

David

 

Not nessecarily screwed.
Did you say that you had coolant in the oil or not.

You may just have a blown head gasket although Normally when it goes that far you might bend the connecting rod as the piston tries to compress the coolant in the cylinder on the compression stroke. Regardless it aint that bad, if you do it yourself, slowly, carefully with a good manual and a buddy to help. Take lots of pictures as you take the bike apart. Once youhave the head and cylinder apart you will know what is what. At worst with luck you will need a new BB 351 kit to solve your problems. At best it is a head gasket. either way you will gain a bunch of knowledge and that is worth way more than the cost of this repair.
Keep positive and take your time.

 

Here you go. Nothing super obvious to me. I don't believe there was coolant in the oil but I changed it this morning and after sitting in the engine and trying to turn it over maybe 5 or 6 times it came out somewhat dirty but it didn't seem watered down with coolant. Most of the coolant came out of the raidator and exhaust when I was taking the bike down. I suppose some may have one in the oil but it wouldn't have been a lot.

So does anything look unusual in the pictures? I don't see any cracks or breaks. The gaskets all looked pretty good. I tore the one on the bottom of the cylinder when removing it but it was intact prior to that. The one thing I noticed was alot of carbon build up on the piston face and around the bottom of the valves. I can not push them and get them to budge at all. I would think that this was a bad thing.

 

That is a rip in the gasket, not a crack in the cylinder housing.

 

I'm not the expert but it appears to be a head gasket leak near the top of the third picture. That thermastat looks like it has failed also.
I've seen in cars where coolant acts like a steam cleaner inside the cylinder. Yours is fugly!
I'm thinking that if the oil wasn't milky or water in it and it was running before, clean it up and replace the gasket and thermastat and go for it.
Your cooling system was probably pressurized with exhaust gases.

 

dacoontz, we won't give you too hard a time...sounds like you have enough of that without our help. On that hose housing part you're showing in the third pic, I'm still not getting the deformed or out-of-round part of your description earlier. Maybe I'm just missing something in your pic.

As far as something being cracked, I'm betting you'll have a head gasket issue instead. The only other problem might be a warpage that you'll want to have someone check on the surfaces where the head and cylinder meet. Yes, you could have a crack somewhere, but it's down the list of likely possibilities.

 

You should not be able to push the valves down with your fingers, those are pretty strong springs. I notice the caps are off of your two exhaust valves. Be very careful that you don't lose the shims!! I see one stuck inside one of the caps.. Do yourself a favor and put the caps back on, be sure the shims are seated correctly, and then stuff a clean rag on them, and tape it down.

To clean the valves and the piston head, get yourself some seafoam and a COPPER brush. Dip the brush and scrub. Be gentle on the valves.

Now the bad.. From what I can see, you definitely need a new head gasket, new thermostat, and I would also replace the piston rings.

You see all the carbon blow by under the top ring? I don't think that should be there. I just ran down and looked at my 250 piston I pulled, and the surface is covered in carbon, but there's no carbon past the first ring at all.

I'd start with those three things, flush your oil real good, flush your coolant with distilled water/vinegar, and cross your fingers that that's it..

Good luck my friend.

 

Sounds good guys. With the thermostat. Are we talking about what I have pictured below? How should it be seated exactly. And the thing i was mentioing about the part is how the the picture below shows a round opening from the engine but the elbow that bolts onto it has one side that is not round. Because of this there isn't the best seal there, granted it didn't have a problme before all this went down anyway.

Any thing I can address about my hard starting problem while I have everything apart? I heard that retiming the valves might be a solution. Can I take that part of my engine to a local shop and say, "Hey, retime my valves please" or how does it work? I know, silly question but just learning here, if that wasn't obvious by now. I do plan on going through the carb while it's out and making sure it super clean before reinstalling, maybe that will help too.

Hey, much thanks for the feedback thus far.

 

I think you have some luck on your side. You've blown the head gasket and run her dry with a faulty thermostat and still have a serviceable bike.

These shots clearly show the blow by from the cylinder into the water jacket Just above the exhaust port.. New head gasket for you my man.





Looks like there has been little or no contamination of the oil (very lucky) and despite the faulty thermostat and the "cook up," the head, valves and cams haven't suffered.

Fit it all back up together with new thermostat, top and base gaskets, fresh oil, filter, and coolant and it should run sweet.

Just read Larrys post and looked at the pictures again, and I too agree that some new rings are in order so add them to the parts list.

BTW, do you have a service manual? I ask because I've shared around plenty of copies to guys on the forum (PDF file.) Just askin'.

As for rebuilding the carb'. If it aint broken, don't fix it! Maybe fix up the cylinder first, and get it running before you look into the carb.

Could have been much worse. You'll be back on the road by the weekend if you get the parts today.

 

I would not worry about the flat side on that elbow. The seal is not made by the whole fitting only the innner discolored part. You should be good but I would recomend you evenly torque all three bolts in steps when you put it back together. If you torque 2 of them down all the way with little to no torque on the third you can **** the fitting a little and less sealing pressure will be applied near the third bolt even if they all have the same final torque.