First ride after top end

[JZ05220r]

Lots of copper flakes in my cooling system makes me concerned that I may have got some in the cylinder as well. I drained the coolant out just after I realized it was still leaking. Let it cool, turned the choke on and revved it to expel/burn any of the coolant out of the cylinder. What an epic fail.

What on Earth are the copper flakes from? Head gasket? How did you get flakes of it into the cooling system?

Buddy I'm sorry you're having so much trouble with this thing, and with multiple cylinders and heads even. I don't think I've ever seen someone have so much difficulty with head gasket leaks as this.
Have you checked the deck for flatness with the cylinder torqued down to the crankcase? Perhaps it can check out completely flat prior to installation but upon install and torquing to crankcase, it distorts the cylinder deck surface?

They are from the copper sprayed head gasket. I guess the coating along the edges around the coolant ports were washed away. I haven’t heard of anyone having this much trouble as well. I really took my time with all of the engine work I have done.

[Chuck78]

Have you ever done a leak down pressure test?
I'd perhaps try to add some dye to the coolant and pressure test, perhaps without the radiators, to see if you could get any transfer of dye across the gasket surfaces, as well as just pressure testing it.

[JZ05220r]

Have you ever done a leak down pressure test?
I'd perhaps try to add some dye to the coolant and pressure test, perhaps without the radiators, to see if you could get any transfer of dye across the gasket surfaces, as well as just pressure testing it.

The dye isn’t a bad idea. Yes I have done a leak down test. Not sure how a crankcase pressure test can be used to pin point a headgasket leak without being able to examine the headgasket for bubbles. If I could find a way to pressurize the cooling system and see how well it holds pressure that would be a good way to determine any leaks. I could use a high pressure cap and use a fitting on the radiator or something to build pressure just below the caps rating and see if it holds for a while.

[John_S]

A while back I suggested getting a MityVac 4510 that's made specifically for motorcycle coolants systems. After writing you about that I ordered one off of Amazon and ran the test on my KDX. It goes right onto the radiator in place of the cap. It also tests the cap separately. It's not something you'll use all the time but it worked great.
Keep the gun held higher than the radiators unless you want to make a mess like I did when I released the pressure.

[bufftester]

Love my MityVac. Have been using it for years. It will also pull vacuum, handy for bleeding brakes among other things.

[JZ05220r]

A while back I suggested getting a MityVac 4510 that's made specifically for motorcycle coolants systems. After writing you about that I ordered one off of Amazon and ran the test on my KDX. It goes right onto the radiator in place of the cap. It also tests the cap separately. It's not something you'll use all the time but it worked great.
Keep the gun held higher than the radiators unless you want to make a mess like I did when I released the pressure.

So it will 100 percent confirm any leaks in the cooling system? I imagine you pressurize the coolant system to 1.6 bar pressure and wait awhile and look for any drops. I want to try that if so. I’m going to follow up with Ken first and see what he thinks at this point. I wanted to add the smoke I was getting out of the exhaust didn’t go away with a 42 pilot stock 220 needle and 155 main jet on the original bored 36mm carb . It didn’t smell like coolant. I’m not sure if it was premix or trans fluid. I do not want to be stuck dealing with that once this coolant issue is said and done. I already noticed dark scuff marks in various areas going up and down the cylinder surface. I’m guessing it might just be the piston coating rubbing away. Can’t lie I have had a terrible experience with the bike so far. I have put WAY too much money and time into it already. Thank you all for following this and giving me your 2 cents.

[JZ05220r]

Ordered a mityvac on Amazon. Will be here tomorrow, this was Ken o connors suggestion as well. I’m going to test with a copper headgasket as well if I can have one cut.

[kdxdazz]

i thought about buying a coolant pressure tester too when i was trying to solve my overheating issues but it didn't make sense to me, cooling system will be pressure tested at 14 PSI, cylinder pressure is 170 PSI from the piston and what would be the pressure when explosion takes place , 1000 PSI???
1000 psi pressure compared to 14 psi pressure
thats why i went with the funnel system but i'm open to being wrong on this

[bufftester]

The funnel method is just a variation of a dynamic pressure check using your eyes instead of a gauge. The mighty vac is usually used to do a static pressure check with the engine not running. You can also do a dynamic test with it. Static testing is quick and easy if you have the equipment. The funnel method is good if you don't have the equipment. Neither is right or wrong, just two different methods to arrive at the same information.

[JZ05220r]

The funnel method is just a variation of a dynamic pressure check using your eyes instead of a gauge. The mighty vac is usually used to do a static pressure check with the engine not running. You can also do a dynamic test with it. Static testing is quick and easy if you have the equipment. The funnel method is good if you don't have the equipment. Neither is right or wrong, just two different methods to arrive at the same information.

Is it ok to test for leaks without any coolant in the system during a static test?

[bufftester]

Best to test with coolant fully topped off. Air compresses, coolant does not.

[JZ05220r]

Best to test with coolant fully topped off. Air compresses, coolant does not.

Yea that’s what I’m going to do. Figured I’ll use distilled water so I don’t waste anymore coolant.

[JZ05220r]

Waiting on a headgasket, if it still doesn’t seal or if it still displays these symptoms/ running weird. I’m gonna start off fresh. I will remove the cylinder and bring the bottom end to Ken O’Connor. I’m not too fond of the bore of the subvalve shaft being corroded to the point where I needed an o ring to replace the oem packing seal, it leaked so much air with the stock packing seal. I will assemble the kips in a brand new kdx 200 cylinder (found one available) and bring that to him as well. I’ll ask him to check/balance the crank with new bearings and seals then assemble the engine with the new cylinder and piston. I think this will be the ticket. I’ll have lots of extra kdx parts to sell on my eBay account. Crazy I know. But this should solve all the issues at this point. I was contemplating buying a brand new yz250x but I can put a small fraction of the cost into this kdx and get it right by taking this approach.