Which top end?

I run the Rkt drop in, great seat of pants power increase, overall happy with it. The downfall with it is more messing around with the fuel controller than I was hoping for mainly because I ride 2 different elevations. One area at 5000'-6500' seems to run good at one set of #s while the other at 7500+ likes another. Not that big of a deal but it took a little to figure both out.
If I were to do it again I'd go rkt direct replacement pistons and spend the rest of the money on a gear down kit and not deal with a controller. I'm more of a rider than a tuner. Lol

If you have a manual and some basic skills replacing a top end is easy IMO.

Doesn't the 13+ mtntk kit require a fuel controller as well?
Edit: No controller for 13+ mtntk kit

i run the MTNTK kit in my 09 assault. still running it with 2000 miles on the kit with the last 500 or so with 8-10lbs of boost.... still looks very good internally!

Have you looked at Northstars piston kit ?

call most wanted performance talk to them about there solution it works

What is the most wanted performance solution?

1700 miles you should be doing a top end or at very least measuring clearances to ensure your not headed for a catastrophic failure. imo

Don't get the RK Tek Kit. There is nothing really wrong with it, but it has issues. The pistons and head are great. Kelsey has a good product, BUT.....The advanced port timing makes the engine very peaky. If you don't pull 8400 rpm its the same as stock. But if you can get you clutching dialed in, it rips. That being said, it is very sensitive to little variations. If the snow sets up a bit or the belt isn't adjusted properly or the temp warms up, it falls below 8400 easily. you will always be adjusting something.

My buddy has the MNTNK kit in his Pro and I find it make the same power as the RK tek kit but has more torque and over a longer power band. It makes really good power from 8000 -8250. So if a few variables change, he is still clutched right and can continue to ride.

Regardless of you not having any issue YET... why would you put pistons in that are cheap and known to fail, when a few hundred dollars gets you a better piston that is lighter and makes more power and runs smoother. Its an easy decision.

goridedoo said:

Assuming he is reffering to their peformance enhancement kit - http://www.mostwantedperformance.com/mwp-research/research.html

Click to expand...

Make more power at 140-150 degrees? That's not what my butt says:face-icon-small-con

700mi on the BMP kit no problems

Long Rod it.

Put 60 miles on the Mtn Tek kit last weekend. Feels stronger than stock and that is even with adding a gram to the inner hole on SLP MTX before I left the garage. Turns same or a little higher rpm with the added gram than stock and the motor obviously is not broke in yet. Hope to get more.

Will say, I think it vibrates just as much as it did before. So don't do a kit in hopes that the vibration in the low end goes away.

I did the Mntkt about the same miles as you. Zero issues before like you but it was never stock. IMO a controller on a '13 adds power and life but you are the proof it can survive without it too lol.
My stock pistons were only 1 thou smaller than the replacements so my pistons did not collapse but the rings and lands were worn. I had ordered and purchased the kit before I took it apart so installed it. Had I taken it apart first I may have cleaned up the ports (reason for my ring failure not piston rock) and gone stock again. the CFI port configuration combined with excessive chamfer from the factory left very little ring support on my cylinders.
Doing the top end is fairly easy but in would be nice to have a second set of hands during monoblock installation. Bleeding the system is as simple as blocking up the front of the sled so the motor is higher than the heat exchangers and burbing it twice.

Couple of things; The pistons in my kit had a steeper crown (1 and a bit degrees) so stick with stock head or talk to MNTKT if that is in your plans.

I purchased my kit based on answers and experiences I got from phone calls. You should too IMO. Especially if you feel you might farm out the installation. Pick someone who has done a few. Things like deglaze, break-in, ring sizing are all just as important a not forgetting the piston pin c-clip lol. The tech or shop with more experience is a better pick no matter which kit they are using.

Don't be afraid of stock. Many top shops still recommend and use stock. Most of these shops are rebuilders not parts installers. After I took mine apart I think I saw why. Just remember the recommended mileage intervals. What you or your tech find (make sure they provide you this too, proves they are rebuilding not just replacing) when you take yours apart will tell you what you need to know for your intervals.
It has to make you think when you read about high milers but it might not pertain to your sled anyway. For instance My sled is the smoothest running twin I have ever had in a sled. But some vibrate from the get go.

Durability lol. IMO real information between the kits is not out there. Info like before and after measurements after x # of miles is real hard to find. Either techs and shops don't keep a journal or don't care to share. On the 'net anyway.
My phone calls showed the Mntkt kit to be out the longest and used the most with good results. Not measurements but comfort in #'s. That was my reason for pre-purchasing that kit.

Hope it helps lol but you are asking a very often asked question with a very un answered history

Remember RK also has just replacement pistons... Another option, and i think theyre around $350-400

Unless i trade up, im just gonna install new OEM or RK's pistons...

I am going to go with RK direct replacement pistons also. Like to keep it simple. No controller. Should be better than stock from what I read. $350 w/out gasket. Check it out on his website.

Running Bikeman's Reliability kit on my 2011, bit over 500 miles, and no issues.

End of season update, 1000 miles, and not a single issue with the Bikeman kit, sled has 3100 total miles, and never had an issue stock or with the Bikeman kit, now for off season mods, a Bikeman head is in order!

I did rk tek replacement pistons and couldn't be happier!

TTT

Interested in more miles of use being thrown in too from users. I'm probably gonna be at a 1000ish with the MNTKT. Should I look inside LOL.
Interested in info from the RKT guys too.

Are we safe now lol.