[B0NE22c]

I have a 95' blaster with a 79' yz400 swapped into it and I'm currently in the process of getting it running but I've hit a roadblock of compression. The engine feels like it has really high compression when I kick it over but when I put the compression tester on it gets a hair over 30psi of compression. I've had the sparkplug out and there's no resistance. I'm ordering new rings but after that I'm lost any ideas?

 

[pygmy warrior]

You should get 30 psi with no rings! Remove the head and have a look. Hopefully you don't a hole in the piston.

 

[B0NE22c]

You should get 30 psi with no rings! Remove the head and have a look. Hopefully you don't a hole in the piston.

I took off the head there isn't a hole in the piston and the cylinder walls look fine there is sme scratches but my finger nail doesn't get caught on them. I'm guessing the next step is removing the jug and checking the rings.

 

[pygmy warrior]

How did the head gasket look? It could be a blown head gasket and/or warped head. Lap the head with sandpaper on a flat surface like glass or granite countertop.

 

[B0NE22c]

How did the head gasket look? It could be a blown head gasket and/or warped head. Lap the head with sandpaper on a flat surface like glass or granite countertop.

It looks fine I did see some black on the mating surface of the head and what looked like exhaust residue on the cooling fins I'll aso add I haven't gotten it to start its only belched fire out the exhaust port

 

[pygmy warrior]

When you reassemble the head gasket use this on both sides.

https://www.autozone.com/sealants-glues-adhesives-and-tape/sealant/p/permatex-copper-high-temperature-spray-a-gasket-sealant-9-oz/520940_0_0?cmpid=PLA:US:EN:AD:NL:1000000:GEN:10758688450&gclid=Cj0KCQjw7KqZBhCBARIsAI-fTKLQubIJmd1Bpv45CK0qfNUPsKOhMtU5w2QIc2lRPVaY2VP0_fLa6M8aAnSwEALw_wcB&gclsrc=aw.ds