THE MOUNTAINHORSE CUSTOM PRO-RIDE-CHASSIS RMK BUILD THREAD

mountainhorse · Apr 8, 2014

Well, after much pondering... I've decided to get a head start on next years custom sled for myself.

After much pondering... I purchased a 2013 RMK (standard model) at a smoking good price.

I pondered many factors....
First, that I would modify the sled to the point where the warranty did not influence my decision... and I wanted a sled that would be up to date with the 2015 models for general features.

The 2013 RMK 800-155 got the "Nod"... The 2013 800 DC-CFi-2 engine, with its thicker cylinder skirts and more evolved mapping than previous years has proven to be reliable over 2 years of "testing in the consumers hands"... Other niceties like PowderTrax running boards on the 2013 make good sense to me.

I also like the more robust aluminum overstructure and the decades proven chaincase.

Over the weeks to come, I'll let this build unfold through photos and descriptions as I build it up.

Stock 2013 800 RMK 155"

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Laundryboy · Apr 8, 2014

How far you gonna go with it?

mountainhorse · Apr 8, 2014

FTX PRO-TECTOR TUNNEL BRACE KIT

The first task in the mission was to strip the sled down to "Zero"

Removing ALL components from the core-chassis.

Bodywork, Front and rear suspension, console, fuel tank, handlebars and controls, complete electrical system, Steering gear, engine, bumpers, snowflaps, track, front and rear suspensions, chaincase, drive-train etc etc etc.

To get it down to the bare chassis.

At that point... the first items to go on are the Fastrax "PRO-Tector" tunnel bracing kit.

The PRO-Chassis RMK tunnels are know to buckle in the area of the tunnel sides directly behind the chaincase and the PTO Driveshaft...in the footwells. I wanted to take measures to minimize that from happening as much as possible.

FastTrax Tunnel PROtector (CLICK HERE)

NOTE: The FTX PROtector kit doe NOT require you to tear down your sled... or even remove things.

CLICK HERE FOR FTX PROtector kit instructions... this will answer a lot of questions you may have.

When I first had it in my hands, I was pretty sceptical about it. I had a chassis torn down to nothing. I installed the kit so I was able to actually feel the before and after... Before that whole area was flimsy... the FTX kit locked everything together and sandwiched the tunnel in that weak area... worth the money IMO.

It should be one of the first upgrades on your PRO RMK for anyone that crashes or hits stumps/rocks with their pro chassis RMK's.. FTX includes everything you need with good instructions to install it easily without tearing down your sled....high quality laser cut stainless steel parts.. even has the long drill bit you'll need..

I also removed the stock mag side (chaincase side) factory outer "doubler" with all the holes in it and made a custom one from .080 6061-T6 sheet, no holes, that covers a larger area... and replaced the stock one with this piece for a little "extra measure" using LORD 406GB adhesive... a buckled tunnel mid season is no fun...I've repaired enough of these to not want to do it again.

FTX Kit and packaging

PTO outer PROtector plate

PTO inner PROtector plate.

Mag side outer PROtector plate and custom doubler plate.

Mag Side Inner PROtector plate

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mountainhorse · Apr 8, 2014

Laundryboy said:
How far you gonna go with it?

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quote-he-s-going-to-go-all-the-way-howard-cosell-221399.jpg

Bcorn · Apr 8, 2014

Keep posting , I'll keep checking back to see how it's going.

fastmnstealth · Apr 8, 2014

What sled did you have before this one? I assumed that you already had a STD RMK.

mountainhorse · Apr 8, 2014

2013 Std Rmk.

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Spaarky · Apr 8, 2014

Could you go through the chaincase side a bit more? I have not dug into a Pro very far, so maybe that would help me. If you have any before pics that would help me. Thanks... Just trying grasp it all for when finally get one and tear into it.

On a side note... I would guess that's the first time you have been asked to be more detailed....:face-icon-small-win. And this thread will be a classic. I can see it coming.

ullose272 · Apr 8, 2014

what are your thoughts on the FTX kit VS the van amburg kit?

mountainhorse · Apr 8, 2014

Both are great kits....both great builders.

I had to choose one in the end.

The FTX for preventive measures... and not needing to disassemble sled much.

The Vanamburg if you want to get into the sled more or you have a buckled tunnel already.

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POLZIN · Apr 9, 2014

when your ready for steering post bushings let me know !

Reg2view · Apr 9, 2014

The 2014 MountainHorse Fantasy RMK Build game. Brought to you by Snowest.com and to be named Sledheads vendors. Weekly prizes and Builder rankings, with a grand unveiling of the sled and crowning of the Ultimate Builder on Halloween, 2014.

Thanks for helping to make the summer shorter, I hope.

kylant · Apr 9, 2014

mountainhorse said:
Both are great kits....both great builders.

I had to choose one in the end.

The FTX for preventive measures... and not needing to disassemble sled much.

The Vanamburg if you want to get into the sled more or you have a buckled tunnel already.

is a “sandwiched” set up with 2 plates per side stronger than just 1 plate per side??

mountainhorse · Apr 9, 2014

Different approaches and to say one is stronger than the other is is pretty subjective. ... if you want the strongest. run both together.

Oregonsledder · Apr 9, 2014

mountainhorse said:
Both are great kits....both great builders.

I had to choose one in the end.

The FTX for preventive measures... and not needing to disassemble sled much.

The Vanamburg if you want to get into the sled more or you have a buckled tunnel already.

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I like the FTX kit. I have installed several and so far no one has a bent tunnel.

04proxr800 · Apr 9, 2014

Do you have to remove the chain case to out the FTX kit in?

Pro-8250 · Apr 9, 2014

Just poking fun at you MH!

Very nice write up! Thank you!
But I will have to say, please don't refer to it as a (standard model) It's far better than anything that is standard. :face-icon-small-coo
800 RMK*155
800 PRO-RMK*155
No mention of standard in any Polaris brochure that I know of. :lips:

volcano buster · Apr 9, 2014

Pro-8250 said:
800 Amateur-RMK*155
800 PRO-RMK*155

:face-icon-small-hap

skippy · Apr 9, 2014

That front cooler is a welcoming sight for me... I'm sick of babysitting the heat gauge on my pro! Good choice going with the Rmk. Later

mountainhorse · Apr 10, 2014

PAINT TIME!!

Next item... Keep the snow and ice from sticking to the sled as much as possible.

Some of that is taken care of on the RMK's already... the "choke" point in the tunnel at the front... The bulkhead heat-exchanger does a good job of keeping the ice/snow from building up there. :face-icon-small-sho

BUT...

Coating the tunnel inside and out seems to be the best way to keep the ice-plaque at bay.

Since the PRO Chassis RMK's use some pretty high tech alloys and bonding agents that are sensitive to too much heat... I chose to paint rather than powdercoat the chassis assembly.

First order of business in any good paint-job is the prep work.

I'm not great with a spray gun in terms of smooth finish or some runs and drips...but the paint work I do... sticks well :amen:

All of the decals were removed and the adhesive residue removed with 3M Adhesive remover. This stuff is worth the investment of having a can on hand... decals... foam tape... foam insulation removal... this stuff just works. Then comes the foam padding under the fuel tank.

The chaincase was de-bonded and bearing supports removed.

Before I started in on the paint prep however... I installed additional tunnel bracing... Timbersled rear Tunnel gussets were "dry fit" and then riveted on with supplemental LORD 406GB adhesive. I sandblasted the gussets for good paint/adhesive "stick".

After that... I sprayed down the entire chassis with Purple-Power degreaser and let it soak a bit to remove all the mill oils from the chassis.
Rinse with hot water... then let dry... After that... a good spray of the entire chassis with Alumiprep-33 cleaner Etch to get good "tooth" for paint adhesion.

NOTE: Make sure to mask the heat exchangers inside the tunnel prior to primer and top-coat....The paint will affect the heat transfer from the coolers and could affect your engine cooling.

I let the chassis dry in a heated room for a few hours. I hung the chassis and then primered using SEM brand self etching primer for good adhesion...

A couple more hours of dry time... and she's ready for top coat.

I really like the catalyzed 1-stage paint from U-Tech... U-Tech 3.8 HSP.
This paint, a replacement for Imron... is tough as nails and rivals any powdercoating I've used... Made for airplanes originally... now common with fleet vehicles and other high demand applications. It holds gloss well and is very abrasion resistant.

It is however pretty nasty...You need to have a good booth or a forced air respirator to be able to shoot it.

For those of you without the right tools to do this... Do the prep work yourself... and take it ready to prime to a local body shop that would be willing to do a small job like this at a reasonable price.

I masked the coolers inside the tunnel for good heat transfer and used old fuel bits to push over all the threaded fasteners on the chassis... I hate chasing threads later.

I'm pleased with the results... though it is by no means a show-pony... a drip here...run there and plenty of orange-peel!!... but hey.. it's a sled!!

It may sound like a lot of work... but it actually goes pretty quickly.