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Posted

I've got a 2005 Brute Force 750 that just had the main timing chain replaced (It broke) along with a couple valves (Bent). The engine work was done by my Mechanic but I removed & reinstalled the motor.

Put it all back together and it fired up nicely. I let it idle for a bit and pulled the dipstick to make sure I hade enough oil in it. Major pressure coming out of the crankcase, it was as if I had my hand in front of the exhaust! Tons of coolant in there as well!

The guy who rebuilt it is very good and I know I put it all back together correctly. He obviously missed something, anyone have any thoughts?

Thanks,

Pete

  • 1 year later...
Posted

Not only did you bend the valves i think you also had a piston with ring problems.  Also, did you replace the valve seals?  Could be getting blowby on the rings.  In regards to coolant in the crankcase i say there's a seal missing or an 

o ring broken somewhere.

Posted

Coolant in the crankcase  sounds like a cracked block  or head to me; although if the head and block  have  water passages  between them  . it could be a head gasket  problem.  Rings and valve seals will  not  let  coolant into the  crankcase ,  but  a bad head gasket or cracked block or head will  let  pressure  and coolant into the crankcase.

Posted

If there is coolant getting into the crank case you would probably have coolant and oil mixture and cause a milky result. If coolant is getting into teh combustion chanber, you'd have a good amount of white smoke when running. Either can be a head gasket, seal, or crack somewhere.

Posted
On 3/21/2017 at 1:03 AM, davefrombc said:

Coolant in the crankcase  sounds like a cracked block  or head to me; although if the head and block  have  water passages  between them  . it could be a head gasket  problem.  Rings and valve seals will  not  let  coolant into the  crankcase ,  but  a bad head gasket or cracked block or head will  let  pressure  and coolant into the crankcase.

a missing seal or broken o ring in the coolant passage will also let coolant into the crankcase.

Posted
On 3/21/2017 at 1:03 AM, davefrombc said:

Coolant in the crankcase  sounds like a cracked block  or head to me; although if the head and block  have  water passages  between them  . it could be a head gasket  problem.  Rings and valve seals will  not  let  coolant into the  crankcase ,  but  a bad head gasket or cracked block or head will  let  pressure  and coolant into the crankcase.

i never said valve seals will let coolant into the crankcase i simply asked a question re the valve seals as were they replaced.  Blowby comes from a broken or worn rings and usually when a valve job is done valve seals should be replaced. a broken gasket anywhere in the coolant train will allow it to gather up in the sump.

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