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Discussion Starter · #1 ·
I recently reassembled my top end after digging into the crank to replace the center gasket and i am seeing coonant filling my cylinder and mixing with other oil.. im getting extreme kickback and i cannot start it of course. There doesnt appear to have any cracks in the cylinder sleve, i have resurfaced the top of the cylinder and the dome, and i have also purchased a new 3-ply copper head gasket as well as a .025 base gasket.. and still coolant is filling my cylinder. It appears my transmission fluid is milky from mixing the two, could that cause my motor to not fire correctly? Has anybody experienced anything like this? Any help is much appreciated, been going at this motor for 2 months and id like to ride before winter comes, thank you!
 

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Crack can be in the casting. Basically opens up from water jacket to the sleeve, then runs down the side of the sleeve to the bottom end. Was an issue with some 300 resleeves. You can plug off the cylinder and do a pressure test to see if it or the head is leaking. It's not definitive as heat and compression from a running motor can open up paths from coolant.

Coolant in Transmission is most likely from water pump seal failure. I suppose it is possible the leak into your transmission case allowed coolant into the crank case via the faulty center case gasket.

Best regards
-Jason
 

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no way coolant should get from cylinder into trans.thats wp mechanical seal issue..as for in case.if the cylinder was re sleeved thats a very common issue.or a person ported it too close to water jacket.
 

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Discussion Starter · #4 ·
no way coolant should get from cylinder into trans.thats wp mechanical seal issue..as for in case.if the cylinder was re sleeved thats a very common issue.or a person ported it too close to water jacket.
The only problem is, i had it running great before i tore it all apart and i went on several rides but when i put it back together i discovered the coolant issue. I never touched the sleeve or the cross hatching since it ran fine before, the only thing i did was cleaned up the piston and rings
 

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Replace MS

Resurface top and bottom of cylinder Square & Flat

Pressure test Cylinder & Head...just as you would a Leak Down test.

Replace Base Gasket

Replace Left & Right Main Seals (for good measure)

Use OEM Metal Head gaskets Only or have Head O-ringed.

Carlos
 
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