670X Blown Gasket

[meierjn]

Good day everyone... Was headed back to the trailer yesterday afternoon when something just didn’t seem right. Was only a couple 100 meters away so decided to go for it. Made it back slowly and noticed the sled was steaming quite a bit. I don’t think it overheated and still had about a half full coolant reservoir. I was hoping it was just a hose but it looks like it is the lower gasket that sits between the crankcase and the cylinders that blew out. I have a few questions…

How difficult would it be to tear this down and replace the gasket myself? I’ve never torn down a sled before but have a fair bit of mechanical experience and am not afraid of a little work!

Should I order a whole gasket kit and replace every gasket or use the old ones? In my experience half the time you end up damaging a gasket and kicking your own a$$ that u didn’t have the one you damaged!

Are there any special tools that I will need? I have a fairly good collection but don’t want to get to a point in the teardown or re-assembly scrambling to find something that I don’t have.

While tearing down is there any other damage I should look for that may have occurred? The engine (top and bottom end) was rebuilt not too long ago so I’m hoping there is no other damage.

Thanks for your help!

 

[magnet]

before you are quick to say its your base gasket check the colant sensors at the top of the head, one of mine came loose this year and was leaking, just a trickle down the back of the jug but it was pooling on the base gasket making it loook like it was the gasket leaking, just about started ripping it apart when i saw the stream coming down the backside.
just a heads up, but if it has to come apart its fairley easy to do.

 

[Bogger]

I'm mechanically retarded and I managed to rebuild the top end on my 670x.

base gasket was cheap... just make sure to clean up top & bottom surfaces well... I used those green plastic scrub pad thingies...

No special tools required... torque wrench for retourquing the head bolts is about it...

Make sure to get the sealed bearings (I think thats what they are called)

Mine took about 4 hours total and I have 1000km on since the rebuild.

I went with BRP original pistons, only needed to replace one but did both just for good measure...

 

[magnet]

I'm mechanically retarded and I managed to rebuild the top end on my 670x.

base gasket was cheap... just make sure to clean up top & bottom surfaces well... I used those green plastic scrub pad thingies...

No special tools required... torque wrench for retourquing the head bolts is about it...

Make sure to get the sealed bearings (I think thats what they are called)

Mine took about 4 hours total and I have 1000km on since the rebuild.

I went with BRP original pistons, only needed to replace one but did both just for good measure...

caged bearings, but you were close booger.

 

[meierjn]

before you are quick to say its your base gasket check the colant sensors at the top of the head, one of mine came loose this year and was leaking, just a trickle down the back of the jug but it was pooling on the base gasket making it loook like it was the gasket leaking, just about started ripping it apart when i saw the stream coming down the backside.
just a heads up, but if it has to come apart its fairley easy to do.

Unfortunately it is the gasket. I can see where it blew out.

 

[meierjn]

I'm mechanically retarded and I managed to rebuild the top end on my 670x.

base gasket was cheap... just make sure to clean up top & bottom surfaces well... I used those green plastic scrub pad thingies...

No special tools required... torque wrench for retourquing the head bolts is about it...

Make sure to get the sealed bearings (I think thats what they are called)

Mine took about 4 hours total and I have 1000km on since the rebuild.

I went with BRP original pistons, only needed to replace one but did both just for good measure...

Woud I need a ring compresser to get the pistons back in after I pull the cylinders?

 

[magnet]

Woud I need a ring compresser to get the pistons back in after I pull the cylinders?

no they slid in from the bottom of the cylinder easily. like booger said he IS mechanically retarded, some might say even incompetant, but he got er done.