MTNTK Drop In Kit question

[newfrank]

Hey all,

I'll be putting in a fresh top end in my 2015 800 switchback assault after this season. It's currently sitting at 2050 miles. I used a borescope to look at how my pistons are doing and they have some pretty gnarly slap going on.

I'll probably be going with the mtntk drop in kit from rec supply since they seem to have the best price I can find in Canada. I'm in Ontario so shipping hopefully won't be too crazy.

Does the drop in kit use the same lighter pistons as their performance kit or the ones for the "fix kit". Or are they all the same?

Thanks,
FRN

 

[neilsleder]

Pm Chrisco in here he will answer any question about there kit!


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[newfrank]

Okay, perfect. Is he the same Chris at rec supply?

 

[HotShotHarry]

Chrisco at Parkland Motor Sports in Stony Plain. He is a site sponsor on here so look under vendors list. Tell-780-963-0080.

 

[newfrank]

Okay thank you for the update. I guess their website no longer works. I sent him a message on here.

 

[TDR]

I put a drop in kit in one of my Pro's and you will love it. Same pieces as fix kit and includes hi compression head, softer valve springs and timing advance key. Wakes up the Pro nicely.

 

[newfrank]

I put a drop in kit in one of my Pro's and you will love it. Same pieces as fix kit and includes hi compression head, softer valve springs and timing advance key. Wakes up the Pro nicely.

Alright so it comes with the regular replacement pistons then? The performance kit (not the fix kit) apparently has lighter pistons for faster revs. Thanks for the info!

 

[newfrank]

Does this kit come with new wrist pin bearings?

 

[TDR]

No it does not.

 

[newfrank]

Alrighty. Appreciate the help.

 

[TDR]

Kit is very straight forward and will make the 800 perform the way it was intended. You will end up with the same power as an Axys. I also changed my primary spring to take advantage of the softer valve springs.

 

[newfrank]

Kit is very straight forward and will make the 800 perform the way it was intended. You will end up with the same power as an Axys. I also changed my primary spring to take advantage of the softer valve springs.

Right on, glad to hear it works well. What was your stock spring and what did you change it to? The one thing I haven't really seen is if any clutching changes are required but I guess I'll find out!

How difficult was it to do the timing key? That's really the only thing I'm not sure about.

 

[TDR]

Timing key is easy but you need a decent puller to get the flywheel off. Went to an SLP spring but I can't recall the color. Very wide range maybe black-pink?

 

[newfrank]

Alright thanks. I'll have to pick up a flywheel puller then. Hopefully I can find a decent one at the shop nearby.

EDIT: Actually I found the Polaris flywheel puller on amazon for 60% off with free shipping to my door by tomorrow evening so that's perfect!
https://www.amazon.ca/gp/product/B00R7ORM12/ref=od_aui_detailpages00?ie=UTF8&psc=1

 

[newfrank]

So an update for anyone that's interested. I pulled apart the engine last night, everything went relatively smoothly for my first time doing it. I had help from my uncle and father and we were able to figure things out. Getting the flywheel off was easy. Hardest part of the whole tear-down was getting the recoil housing off. Had to pull 2 engine mount bolts and pry the motor up slightly.

The cylinders looked pretty good, I have them at my dealer right now getting de-glazed and measured up to make sure everything is within spec. The only issue I had was I broke the stud off of my mag side power valve so I had to buy a new guillotine to fix it. The injectors came out fairly easily and the two o-rings looks to be in great shape. No issues there.

I received the drop in kit today from Chris at Parkland and it will be going in to the sled on Friday. Super nice guy to deal with and I'm happy with the price I paid.
When I get back to the shop, I'll have to pull the throttle bodies to install the Boyesen stock replacement petals. After that, I need to install the timing key and then the pistons and cylinders.

 

[TDR]

Sorry my bad. I should have mentioned about pulling the bolt from the engine mount. Minor but still a PITA.

 

[newfrank]

Sorry my bad. I should have mentioned about pulling the bolt from the engine mount. Minor but still a PITA.

It's all good. I pulled up the shop manual and it explained how to do it so I was able to figure it hit fairly quickly.

 

[Heimie]

I have done this on my Assault. I run the SLP blue/pink primary (my factory one was broken) and had to increase the primary weight. I now have the SLP Magnum Force adjustables. Very happy with them. The new weights pull VERY hard near the top RPM range. I'm running a total of 62.5 grams. Working great at 7000 ft.


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[newfrank]

I have done this on my Assault. I run the SLP blue/pink primary (my factory one was broken) and had to increase the primary weight. I now have the SLP Magnum Force adjustables. Very happy with them. The new weights pull VERY hard near the top RPM range. I'm running a total of 62.5 grams. Working great at 7000 ft.


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I'll have to see how it performs after I install my kit. I'm only st 500-1000ft so I'm not sure where to start in terms of clutching.

 

[dragonweld28]

All you will need to do is add some weight to the primary and a slightly stiffer spring. Polaris 10-70 weights and a SLP blue pink spring will be perfect for where your riding.