Mutt Motor 777

[TxPro1200]

built a mutt motor 777 for the wifes couch.the 700 grenaded and it needed upgrading.used the 700 cases, some 1200 jugs i already had,and the stock domes off my 1200 tx i replaced with 92 domes.this 777 has a reconfigured 1200 crank which has less rotating mass than the octane crank.set of carbon tech petals,and true twin 40mm keihins,not those bullpoop 38's that are all polaris offered on any twin they built.still in the process of breaking it in but i can tell its under propped with the 700 stuff.

 

[VXSXH20]

any pics of the assembly process? does it use a PTO shaft on the crank end or a spin on coupler like the octane?

 

[TxPro1200]

can put up some pics later,its a pwc 1200 crank with the middle web's pulled out and reclocked to a twin,has a spin on coupler,didn't build the crank myself.

 

[speedysprocket]

Who built the crank?
Here's my "mutt". "Rebuilt" crank was rusty when we tore it down, so getting rebuilt again. I might try the pork chops when I rebuild my 950's crank...

 

[speedysprocket]

built a mutt motor 777 for the wifes couch.the 700 grenaded and it needed upgrading.used the 700 cases, some 1200 jugs i already had,and the stock domes off my 1200 tx i replaced with 92 domes.this 777 has a reconfigured 1200 crank which has less rotating mass than the octane crank.set of carbon tech petals,and true twin 40mm keihins,not those bullpoop 38's that are all polaris offered on any twin they built.still in the process of breaking it in but i can tell its under propped with the 700 stuff.

Which triple cranks have the 70mm stroke and the lighter design? Do you still need a 777 crank for any parts?

 

[TxPro1200]

only the octane and the 800 virage i have the full circle 70mm crank.all the 1200's have the pork chop 70mm crank.you running msx jugs in that octane?who did the head cover?can he do another?

 

[speedysprocket]

only the octane and the 800 virage i have the full circle 70mm crank.all the 1200's have the pork chop 70mm crank.you running msx jugs in that octane?who did the head cover?can he do another?

That's a snow mobile top end. Porting sucks for freestyle jet skiing, so it's at TPE to have the cases decked and ports tweaked for some better bottom end.
I want to do a light weight crank for my 950 Polaris, though...

 

[TxPro1200]

buddy is building an octane with 2 of the msx 1200 jugs.he's gonna need a head like what you have.where did you get yours? is it a snowmobile piece?just noticed the power valves,so i should have known they were snowmobile stuff.i know a guy that added the power valves to the pwc jugs like that

 

[speedysprocket]

buddy is building an octane with 2 of the msx 1200 jugs.he's gonna need a head like what you have.where did you get yours? is it a snowmobile piece?just noticed the power valves,so i should have known they were snowmobile stuff.i know a guy that added the power valves to the pwc jugs like that

Yes, that's a snow mobile cylinder head and cover.
This is my baby though:

http://www.x-h2o.com/index.php?threads/polaris-foot-rocket-build.135206/

 

[TxPro1200]

sbt makes a 1200 sleeve with triple ports that are pwc specs.the red 800 head what did it come off of?is it a one piece thing with the domes in it or are the domes interchangeable?

 

[speedysprocket]

That's the water jacket cover. The head underneath that does not have removable domes. The cylinders are also nikasil- no sleeves to rust or bore, less friction, harder, better heat transfer... I think they have the auxiliary exhaust ports, too. This stuff comes off early 2000 snow mobiles, mainly the xc800, I think. Search ebay.

 

[VXSXH20]

I believe that is a Polaris Liberty 800 XC Sled head. The top is oring'd to sit on a one piece casted head with built in domes. OEM heads are don't have interchangeable domes. but some aftermarket head bases can...

 

[VXSXH20]

oops speedy beat me to it.. hence the name!

 

[speedysprocket]

built a mutt motor 777 for the wifes couch.the 700 grenaded and it needed upgrading.used the 700 cases, some 1200 jugs i already had,and the stock domes off my 1200 tx i replaced with 92 domes.this 777 has a reconfigured 1200 crank which has less rotating mass than the octane crank.set of carbon tech petals,and true twin 40mm keihins,not those bullpoop 38's that are all polaris offered on any twin they built.still in the process of breaking it in but i can tell its under propped with the 700 stuff.

Who built your crank and what bearings/rods did you use?

 

[speedysprocket]

sbt makes a 1200 sleeve with triple ports that are pwc specs.the red 800 head what did it come off of?is it a one piece thing with the domes in it or are the domes interchangeable?

Who built your crank and what bearings/rods did you use?

 

[TxPro1200]

all polaris bearings.still running my first intial jetting setup.was rich last time i looked at the wash.opened the stinger from .055 to .059.last run i made it went 6910 rpm.i suspect the props a little worn and under pitched but not bad for a 3 seater.with the right prop and a 6 pump wedge i'm pretty sure it'll see 56-57 mph

 

[speedysprocket]

I had Crank Works turn a triple into a 777 crank for me with all ADR parts. Still waiting for it to get assembled, though...