Reddit reviews Block Tester BT-500 Combustion Leak Test Kit - Made in USA

Can you see it leaking onto the ground anywhere. If not then its internal and because it foaming this is most likely the case. Since its foaming its getting air pressure from somewhere, its either a cracked head, block or head gasket. There are other internal leaks but none that would cause foaming. What i recommend you do is rent a block tester, most parts stores will do this.

That radiator is plugged, or there is no flow going through it. You can try to flush it out with a garden hose, but that will likely only clean out one path for the coolant to go through (ie. You won't be using the whole radiator to cool the coolant).

Simply because it has been overheating though, I would do a block test just to make sure the headgasket is still good.

Here's my bike's cold start at 65 F. Sorry for the poor sound quality. As you can see it's spitting out a good amount of water.

Did your previous bikes have an aftermarket exhaust or straight pipe?

If you're still concerned about a HG leak, get one of these to detect exhaust gases in the cooling system.

You need to block test it...you can buy a kit fairly cheap....basically looks like turkey baster with 2 chambers...Napa sells the fluid...the fluid reacts exhaust gas mixing in the coolant,the fluid starts out blue and will change from green to yellow if exhaust gas is detected.

I use it daily in the shop out here in AZ

https://www.amazon.com/dp/B06VVBSFTF/ref=cm_sw_r_other_apa_i_HQehDbTWGEVGB

Might wanna grab one of these too you have to buy the test fluid ~$10 but the tool can be rented.

Block Tester BT-500 Combustion Leak Test Kit - Made in USA https://www.amazon.com/dp/B06VVBSFTF/ref=cm_sw_r_cp_api_i_kktXCbF2CRE2M

Not newer ones no, Ive done a 4-cyl rebuild/swap in my 78 but Im very far from a pro. Isnt dealer software expensive?

As for a headgasket tester, are you thinking of something like this?
https://www.amazon.com/Block-Tester-BT-500-Combustion-Leak/dp/B06VVBSFTF/ref=sr_1_2?ie=UTF8&qid=1520003646&sr=8-2&keywords=head+gasket+test

Can you give us a picture of the oil?

I would first check for combustion gasses in the coolant using one of these

Coolant in oil is super common on these engines, and the most common failure is the head gasket.

Perform a block test with this

Yes, there is. Follow the directions. The fluid will turn a particular color if exhaust gases are detected in the coolant (indicative of a failing head gasket, because it allows exhaust gases into the cooling jackets).

get a head gasket failure tester instructions are pretty clear, you sample your coolant and ad the dye, if it turns a certain color than exhaust gas is getting into your cooling system.

Had an extremely similar set of circumstances on my 2005 Civic, did the thermostat, changed the coolant, and no matter what I did I had extra pressure happening in the cooling system, it happened to be the head gasket failing on the exhaust side of the gasket.

Either take it to a shop, or buy one of these to check:

https://www.amazon.com/Block-Tester-BT-500-Combustion-Leak/dp/B06VVBSFTF

99 doesn't necessarily mean you're immune from a cracked head, but it does mean you're a whole lot less likely to fall victim to it. If combustion gasses are getting into the cooling system it could also be warped or could just be a bad head gasket. I believe most parts stores sell the kits, Autozone might even rent them. I ordered mine off Amazon iirc. Most shops should also be able to perform this test but I have no idea what they'd charge for the service.

Block Tester BT-500 Combustion Leak Test Kit - Made in USA https://www.amazon.com/dp/B06VVBSFTF/ref=cm_sw_r_cp_apa_i_wCTHDbVV6NPNJ

I use this one. Works like a charm.