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Discussion Starter #1
Well i changed the piston and gaskets when i got it but i seem to have a new issue. Im getting the same amount of fuel but I'm like between 15 and 20:1 afr all of a sudden...so I'm guessing a head gasket because I lost about 15oz of coolant in about 30 min of riding and it's not leaking while it sits....and now I cant get it to run right at all. Out of the blue. I didnt have the head leveled last time for money's sake but I think I messed up. Lol I dont see it in my crank case oil but it happened quick so it may not have made a big color change yet.

What do you guys think?

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Well i changed the piston and gaskets when i got it but i seem to have a new issue. Im getting the same amount of fuel but I'm like between 15 and 20:1 afr all of a sudden...so I'm guessing a head gasket because I lost about 15oz of coolant in about 30 min of riding and it's not leaking while it sits....and now I cant get it to run right at all. Out of the blue. I didnt have the head leveled last time for money's sake but I think I messed up. Lol I dont see it in my crank case oil but it happened quick so it may not have made a big color change yet.

What do you guys think?

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When you torqued the head bolts did you go more than 44 ft-lbs with the stock head bolts....& did you do a re-torquing after 1 heat cycle/riding it for a day ???

And did you use new copper/plated washers on the M10 head bolts as required....???

Also it's a good idea to use oil on the m10 head bolts threads to prevent seizure....!!!

I think it's a blown head gasket due to head bolts stretching...do a compression test...!!

(note service manual)

Replace all the 10 mm cylinder head bolt washers with
new ones.
○The 10 mm cylinder head bolt washers are copper-plated,
and they could leak oil if reused. •Apply molybdenum disulfide oil to the both sides [A] of the
10 mm cylinder head bolt washer and thread of the 10
mm cylinder head bolts.

I recommend KMS head bolts & never worry about blown head gaskets... https://www.ebay.com/itm/Kawasaki-KFX450R-KFX-450R-KMS-ARP-Stronger-Heavy-Duty-Cylinder-Head-Studs-Kit/192125434778?hash=item2cbb917b9a:g:3AgAAOSwxMRbl8AD:sc:USPSFirstClass!86404!US!-1
 

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Discussion Starter #3
Yeah I bought a copper washer kit and replaced every one. I went with the advice u gave 44ftlb. But I did not go back in and retighten them. I put oil on the arp studs when inserting them, and used high temp sealer very lightly.

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Discussion Starter #4
I bought the newest head studs from arp... they were stronger than the original arp studs. 10mm

I'm hoping to reuse them right? As long as no damage is present....

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Discussion Starter #5
The moly oil I will buy....I'm looking for it and what I see is a powder, a grease, and an oil additive....which one? I know u said oil but since it's an additive I thought I'd better ask?

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Discussion Starter #6
Studs are
ARP2000 grade, stronger than the ARP 8740 chromoly!



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Discussion Starter #8
Yup, compression is down to 45 psi. When I put it back together last time it was 67psi.

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Discussion Starter #9
2 questions....

1. I found that my resivor outlet line was plugged off and all of my lines connected well. It had coolant seeping by my radiator cap and drizzling down the radiator when hot and full. I can see the dried marks. Could this had something to do with the probable blown head gasket??

2. Would you get the head resurfaced? I mean make sure it's not warped... cuz I dont think I'll have a way to do that locally and it's not likely to be cheap.

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Discussion Starter #10
Definitely a blown gasket. It looks to me as if it wasnt far from blowing a second spot almost opposite of the first one. Those pics are taken untouched. You can see the difference in the black color on the gasket and carbon... the studs broke free at about 42 ft lbs. And my head cover gasket was damaged and I didnt do it. It was brand new. I ordered another one.

Do you guys agree? What do u see??

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Did you use oem gaskets?
 

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Definitely a blown gasket. It looks to me as if it wasnt far from blowing a second spot almost opposite of the first one. Those pics are taken untouched. You can see the difference in the black color on the gasket and carbon... the studs broke free at about 42 ft lbs. And my head cover gasket was damaged and I didnt do it. It was brand new. I ordered another one.

Do you guys agree? What do u see??

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Your quote...(the studs broke free at about 42 ft lbs)...

You mean they pulled out of the crank case threads..If yes...Helicoil all 4 M10 threads to prevent...???

Stock head bolts don't torque over 44ft-lbs...& use new copper plated with the stock head bolts....!!

"Don't" use the copper plated washer with ARP head studs use the washer it's came with (only)...you can torque up to 48~50 ft-lbs that's recommended by ARP...
 

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Discussion Starter #14
I think it was a wiseco head gasket last time. I did use the arp washers. I remember now I bought the copper washer set and then didnt even need them.

My head studs are all fine. I meant that the nuts broke free at around 42 ft lbs. I put them in at 44 ft lbs. I'm pretty sure that it was a suggestion to me not to go over 44 ft lbs... even though they said 48 to 50. Either way I dont recall retourquing them.

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Discussion Starter #15
48 ft-lbs is max....because of the aluminum case threads & the ARP studs are for high performance race motors for drag racing or Pro MX when the KFX450 was still in production...see picture

I'd stay around 46 ft-lb since your not running a turbocharger, nitrous oxide or an 14:1 or higher compression piston....!!

You said 46 my mistake.

So put them in at 48ftlb?

What's the best head gasket?

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Oem head gasket is the only way to go.

They should be able to plain your head and get it flat fairly easy.

But I suspect the wiseco gasket may be partially to blame
 

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Discussion Starter #17
Well that sucks cuz I just ordered a tusk gasket kit yesterday. It was going to get here the fastest.

I'll try and find a machine shop in the area that can level it. I'm kinda in a pinch right now and I'll probably put it back together with the tusk gasket and order a factory gasket, and tear it back down.

Should I pull the cylinder up too?

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Discussion Starter #18
And I ordered a new spring for the exhaust cam. My bike never wants to start really easy. A head gasket may have had something to do with that, but I'm going to replace everything until it does start easily. The valve tolerances are right.

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Main and head gasket should be oem

You will likely keep having issues.

Rocky mtn has oem parts and quick shipping.

Weak oem coil could also be to blame. Or tps is a little under spec
 

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Discussion Starter #20
I have an accel jeep coil. And luckily I found a machine shop that I'm taking it to tomorrow, and he said if it will fit on his machine he will do it for me.

Next time it comes apart I will have the oem gaskets waiting.

And I meant right now....I pulled the head off but not the cylinder.... do I need to take it off too?

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