what should I do with my 98 RMK roller?

[cowboy181d]

Hey guys
I got a 98 RMK roller in my shop. What should I do build the shiz out of the Ultra 680 I have. Or turbo the VES 800 I need to rebuild? both motors need rebuilt.680 has a scuffed cylinder. 800 take a guess at why it don't run.......

I am wanting to build it up just for a fun back up for my backup

I am thinking 159, edge skid and cut the running boards off in favor of a set of VE style boondocker running boards.


this is just a wild Idea I have as of now but would like a no holds bar idea session as no matter what I do It will be a long term project! As I am still in the process of building my IFS swap on my 79 TXL...

 

[retiredpop]

Go for the 680 buildup.
There's nothing sweeter than a triple imo.

 

[SpencerA]

If you decide not to rebuild your 680 then I'll buy it off you.

 

[cowboy181d]

I have been thinking about big boring that 680 would be sweet! and probably just a touch more reliable than turboing a 800 twin!

 

[sno*jet]

single piped 680 w/ turbo? ive always wondered...

 

[cowboy181d]

yeah me too....that was one my first thoughts.......

 

[mike_s]

You can get 850 cc's out of that ultra engine if you have it sleeved, and 175-200 hp if you have it setup right. I just rebilt mine after 10 years of reliable service. Was still running but was getting tired. Ive always been partial to the tripples. Just love the way they run.

P.s. The ultra engines absolutely hated breathing through a single pipe. I think youd be better off ditching the turbo idea for that reason plus it is a ton of work to get a turbo to work well with carbs. Perfectly doable but tough.

 

[cowboy181d]

yeah I have turboed/supercharged many 4 stroke engines but never a 2 stroke so I doubt I would do it to a triple...but sure would be fun to try, I agree 100% about the single pipe thing I decided to go big bore triple now I just have to find the "recipe" I want to use I am thinking sleeves as I am hell or high water to find a new big bore kit on the net...If I remember right LA sleeve makes a big bore sleeve set for these 680's to punch them out to 800..correct me If i'm wrong though.

 

[mike_s]

yeah I have turboed/supercharged many 4 stroke engines but never a 2 stroke so I doubt I would do it to a triple...but sure would be fun to try, I agree 100% about the single pipe thing I decided to go big bore triple now I just have to find the "recipe" I want to use I am thinking sleeves as I am hell or high water to find a new big bore kit on the net...If I remember right LA sleeve makes a big bore sleeve set for these 680's to punch them out to 800..correct me If i'm wrong though.

Its been so long since mine has been sleeved...i dont remember who did it. I do know that i have always run polaris storm 800 pistons. My heads are one-off, but you will need to find some for this aplication. HTG used to do alot with this platform, they may be someone to talk to.

 

[cole_151]

Ultra 800 BB

Northside Radiator and performance in Stewartville,MN do an ultra 800 BB kit with storm pistons. They have custom porting done to there spec have the cylinders bored and run skidoo flat side rack carbs i know they are very reasonable and also Mike and Lonnie are top notch guys Give them a call they would set you up 507-533-7780


I forgot to mention they have tons of ultra spare parts and motors.

 

[mike_s]

Northside Radiator and performance in Stewartville,MN do an ultra 800 BB kit with storm pistons. They have custom porting done to there spec have the cylinders bored and run skidoo flat side rack carbs i know they are very reasonable and also Mike and Lonnie are top notch guys Give them a call they would set you up 507-533-7780


I forgot to mention they have tons of ultra spare parts and motors.

This part in red is especially good to know, its getting tough to find good parts for the ultra and 800 xcr engines. Thanks!