need HELP! tecate head gasket... pics of 2nd bad gasket and mating surfaces

**2quicktecate** · 02-02-2009, 02:15 AM

my gasket seal for a few hours and then started blowing compression in the cooling system here's some pics of the cometic gasket the head and the jug. i think the machine shop's shitty belt sander mill has to ddep of scratches and thats where it's blowing passed.. what do you guys think. any help would be greatly appreciated.

**Twilight** · 02-02-2009, 02:45 AM

Its definitely the head man, those scratches look bad.

When I did the top end of my FL400 pilot, I used a SMALL amount of copper spray to help seal, has held up so far with 11 hours on the top end. You can also finding one thats thicker.

**dcreel** · 02-02-2009, 02:52 AM

Do you leak water out of the overflow? I am having the same problem with my 85. I put a new oem head gasket on it, and the head isn't leaking outside of the cylinder anymore. But as soon as I start it, it just pours out of the radiator overflow. The gasket was correctly put in, and torqued correctly. It's fast as hell with the water leak. I can't even imagine if I can get this thing running correctly.
kx250 ported cylinder, boyesen reeds, reed spacer, 41mm Mikuni flat slide. DG pipe and silencer, motoplat ignition.
How would you clean a radiator out? How do you check the radiator impeller to see if it is working?

**Twilight** · 02-02-2009, 02:56 AM

dc reel- are you sure its not upside down?

to check the impeller, i take the tube off and pour water into it, if it comes into the radiator, it works?

To clean, I would get some flushing fluid like what cars use.

**dcreel** · 02-02-2009, 03:00 AM

I'm 99% positive its in correctly. It was an oem so it had the up on it, and I also used the OEM manual. How is the water going to go uphill to the radiator? Are you talking about while it is running? Which hose do you pour into, the one going to the water pump or head?
Thank you,

Sorry about the hijack 2quicktecate

**Twilight** · 02-02-2009, 03:15 AM

one going into the water pump, and if anything, unplug the hose that goes out of the radiator too and just watch the water come out.

should be fine if you run it only for a few minutes. Also, sounds like the water is being blocked, flush the radiators while you have the hoses unplugged and run straight up water from the hose through them and see if it all flows in and out with no issues.

**2quicktecate** · 02-02-2009, 03:27 AM

mine leaks out of the overflow. it sealed for an hour or, and then started blowing water out the overflow. it's definately getting compression through the ring on the gasket. you can see it, the black lines from the deep scratches. i had a thick piece of glass and resurfecad the head a few minutes ago i went all the way up to 2000 grit. its smooth and flat now. i bought a cometic gasket last time, should i go with oem? the oem sealing ring is twice as thick. if you run my bike with the coolant cap off you can see the bubbles and if you plug the hole with your thumb you can feel and here the pressure build up right away. i'm pissed about that shop they just scratched up the head with 10 grit and promised it would seal. i think i got it this time though. hey, dcreel, i need a bigger carb and don't know what to get, is there something oem off a newer bike that will increase the performance off my bike? i have a stock carb ported and jetted to the moon.

**dcreel** · 02-02-2009, 03:49 AM

I'm a huge fan of Mikuni flat slide carbs. I have a few stock Mikuni Tecate carbs laying around. You did say yours was ported to 41mm right?

**2quicktecate** · 02-02-2009, 04:35 AM

i dont know, it looks small. thought it was a 34mm

**nd4speed** · 02-02-2009, 10:10 AM

Isn't the head gasket supposed to melt to create the proper seal?

Only time I had head gasket problems on my old machines is when I used torque specs from a manual. I went back to over tightening them by feel and all was good again. Torque wrenches are over-rated unless the parts are like new IMO.

Wow, I guess that sleeve is a little lower. Most would say that is your problem. I would have the cylinder decked if the problem continues after changing the head and gasket.

The cylinder head I sold you worked well. Who ever did the porting probably cut it too.

**2quicktecate** · 02-02-2009, 02:52 PM

yeah i wish i would have left that head on there, it had a oem gasket in it too. thats what i'm gonna try this time. if that dont work i guess i'll have the top of the jug lighty milled, and try a stock head so my compression isn't too high.

**2quicktecate** · 02-02-2009, 02:55 PM

i hope you don't think i'm complaining to you about this... i feel i got a great deal on this top end from you, i'm just working the bugs out of a home built budget motor that eats banshee's.

**2quicktecate** · 02-02-2009, 02:57 PM

what if i get the top of the jug cut to be even with the sleeve and double the cyl. base gaskets? that should be ok i think...

**DeePa** · 02-02-2009, 03:36 PM

half-ass fix IMO

**Dirtcrasher** · 02-02-2009, 03:50 PM

The sleeve looks way too low to me!

Not sure how to fix that correctly at this point (easily) but it's wrong.

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need HELP! tecate head gasket... pics of 2nd bad gasket and mating surfaces