TOPIC:

Well, it happened.

Some time ago I ran my head loose, lost compression, yadda yadda. I always suspected that after that happened, the head gasket was kind of compromised. Well, it was. over 2,000 miles later it happened - To take the subject on my original post from a few years ago, it was truly '80 to zero, head scratcher' again, but this time with lots of smoke!

I'm not really sure how to proceed on this. The metal on both the head and jug was actually 'burned?' away, you can see it is pitted and has chunks missing.
I'm not sure machining can save this, or even who would have the knowledge to do it. Also there is a crack in the #3 head between the spark plug hole and valve.

Debating on sending the whole engine to Redline for them to re-build with undercut tranny, new cam chain (both things I didn't do when I redid the top end only a few years back) and hopefully sourcing a good head and jugs. Any experience with them? If I send this out, I want someone who specialized in these engines. I need affirmation that the damage cannot be fixed - I don't think that simply decking the head is going to do anything because the metal is eaten away. Same for the jug - It would be simple to re-sleeve but what about where the metal was blasted away? And again, if I am going back into this I think it would be smart to do the cam chain (which is original and stretched to out-of-spec) and transmission.

I had good luck with Joe Hooper at Pit Stop when I did the top end rebuild, but I know that Joe is getting long in the tooth and not sure if he is really still doing the Pit Stop thing. Also at the time I lived in Orlando so I could drive to his shop. Now I am in San Diego.

I would like some input and advice on how to proceed. This happened in Mexico when I was 120 miles from home - My friend and I towed the thing with my KLR the whole way. That was a funny border crossing. This happened almost a year ago but I let the thing sit in punishment for a good 6 months before I touched it!

That cylinder is junk. Not sure about the head but that doesn't look good either. Probably could be fixed by welding but at what cost?

Wondering if you followed up after the rebuild with torque checks on the head nuts? I've seen drastic torque fall off when using Athena gaskets so I only use OEM gaskets now. Reason for mentioning is because your engine looks to have lost compression on the nuts which allowed the head gasket to blow out. Don't think that would happen otherwise unless the head was drastically warped.

Wow. Looks way too deep to machine out safely on both the block and head. Might want to do what I did, and get a decent used block and head and send them out to APE. Not cheap, but good work.

Nessism,
That is exactly what happened. I did not re torque after the rebuild a few years ago and lost compression. If you search the forum I had a pretty lengthy post on it a couple years ago. I think the gasket was probably damaged when that happened, and I just got 2,000 more miles with good luck. But all the signs point to that. I felt like an idiot - The bike was running great and looking good and I put so much time into it and didn't follow up on a 10 minute maintenance task.

I agree it is too deep and wouldn't trust welding.

I will look into APE. That is a good idea. I haven't really crunched the numbers on budget, but right now I have a boat anchor. Am willing to pay for it to be done correctly and give me 40,000 more miles.

To Bad
Well, You were close to Joe Hooper when you needed work before.
If not wanting to go back to him for more work due to distance
Then drive over to APE north of LA and give Jay a try
Dave

I allowed myself self to get to the end of your first paragraph before i realized that the best way to repair this would be to give the bike to someone that is willing to do the simple maintenance task's to keep it running, then get your self an electric scooter with solid wheels and maintenance free battery that you would only have to plug in and if you are feeling really energetic, clean.


Some time ago I ran my head loose, lost compression, yadda yadda. I always suspected that after that happened, the head gasket was kind of compromised. Well, it was. over 2,000 miles later it happened - To take the subject on my original post from a few years ago, it was truly '80 to zero, head scratcher' again, but this time with lots of smoke!

What head gasket(s) did you use? Cometic or OEM? Yes, you should re-torque at minimum after 500 miles, but a combustion leak serious enough to burn decks like that after 2k shouldn't have happened regardless. From what I've heard of and experienced, the biggest KZ head gasket issues are oil leaks. Must have been an underlying cause; didn't torque correctly, warped head or block, deck scoring, overheat, etc.

agree with Vtec statment

A quick timeline to clarify:

Rebuilt top end. Torque to spec. Ran for maybe 100 miles, re-torqued. Where I screwed up was not following up at the 500 or 1000 mile re torque. Somewhere around 2,000 miles after the rebuild I lost compression to where the bike would not run. Re torqued and the engine fired up and ran great for another 2,000 miles until this happened (at the end of a 500+ mile hot weekend in Mexico) I did check the torque somewhere in between there, and believe I did before we left on the ride as well as did a bunch of other maintenance. In retrospect, I believe the head gasket was compromised at the 2,000 mile mark causing this. When I disassembled, the head nuts were not exactly 'loose'.

Vtec, I do not recall what brand head gaskets were. I could look at my receipt from Joe in my file. All the parts came from him. Interesting information about the oil leak - Perhaps oil was leaking in from a passage and got in between the head there and exacerbated the problem. Would you agree that the domes and valves all look pretty good despite this? I saw no real evidence of poor running or overheating on 3 or 4. Not sure about the crack at the plug though.

Kevski, thanks for the completely worthless and demeaning feedback. I wish you a litany of mechanical problems in the future.

Joe typically uses Cometic Brand Gaskets which are used by stock bikes and hardcore racers world wide. Some here will tell you stock gaskets are ONLY way to go. I tend to pick and choose which ones work for me . I personally use cometic head gaskets but also like OEM head gaskets. No oil flows between cylinders 3 and 4 . Oil is outboard at each end of motor.
Guessing , You shouldnt have skipped retorque of head at 500 miles AND Just how hot did you get a air cooled motor in Mexico ?????

One last thing .
Im watching this very closely and will lock a good thread down if a Flame War ignites.
And that will not serve the original poster solve his problem
Dave

Dave, good point about the oil passage location. Without it in front of me I didn't recall.

I mean, it was hot down there...but I was going 60+, not like I was sitting cooking at stoplights the whole time.

Anyhow, what's done is done - I have a decent idea on how to proceed and in addition to this repair will be needing a new cam chain, etc. so it will be time to split the cases and do the whole thing from the bottom up anyway. And I am OK with having this done at a shop...Not sure if APE does engine builds or just mainly machining. That is why I liked Joe, he did it all. In the case of the top end he did all machining and I did assembly. I would rather find a head, jugs, and send my bottom end off for complete machining and assembly and would want someone who knows better than me to go through and check bearings, etc. since this is a 42 year old machine with 56k on the clock. Another alternative to APE is Redline - I have bought good used parts from them before as well.

Sounds like you are forming a plan .
I think Redline shut down all operations . I also used to buy from him and the website is still up but I think he is closed
It would be good to know for sure.
So if I were you I would do all my disassembly and check each part and ask questions here on individual parts and systems.
Call Joe Hooper , and Jay and others and decide how to move ahead from there. WE can also refer you to smaller shops for single items like crank, trans , and headwork.
Most of us on this site do our own work other than specialty work we dont have the equipment for.
If you decide to do that then we are here to help.
What was air temp on this Mexico trip ?
Dave