MX banshee motor

[rjayb]

I'm in the infant stages of planning a complete mx build that will most likely be done in a Laeger or Lonestar chassis.  Curious what all you trail and mx guys are running for motor and pipe combos  I've had a stock cylinder unported with FMF's and T5's, ported stock cylinder with T5's, Stock cylinder 4mil with Shearers, and current setup on my duner is a 421 ported Serval with Shearers.  I have dyno charts for most of the motors I've had so if you have graphs of yours, it would be cool to see for a comparison.  This will be a long build so I'd like to get an idea of what potential engine and exhaust components I should keep an eye out for.  Thanks.

[Deadbeat]

whats wrong with the current set up

[BANSHEEBEEFM2M]

421 serval ftw

[locogato11283]

I would run the 421 Serval. I would swap pipes to something custom for your setup. LED could build you a set to compliment your motor.

[rjayb]

whats wrong with the current set up

Current setup is my duner and it's tits on.  This is going to be a completely new build frame up.  Was just throwing out motors I've owned so people would have an idea for comparison and my experience.

[rjayb]

I would run the 421 Serval. I would swap pipes to something custom for your setup. LED could build you a set to compliment your motor.

That's what I was thinking but worry on a stock length or possible -1 arm it might be too much motor.  I was thinking something in the 65 hp range would be plenty for mx. 

[rjayb]

Going to catch shit for this, but why not a single carb setup with like PT pipes on a serval?

 

I know DDQ ran this setup for MX and the curve is great.

 

I ran a single carb with FMFs and it had a decent curve.

I like the idea of pt's on a setup like this because it puts the expansion chambers out of the way.  I'm a big guy and most pipes still get me right above my boots if I'm really cornering aggressively.  When I built my current setup and was looking at pipes I heard that the servals really didn't like the traditional mid range pipes.  Guys thought if they paired some pt mids with a serval they would have this ridiculous torque monster and for reasons beyond my pay grade didn't pan out.

[m671054]

I know this is a banshee forum and im probably gonna catch hell for this but what about a newer ktm 250 or 300 motor. Low to mid 50 hp stock i believe.

[rjayb]

That KTM 300 motor is badass!  Going with a banshee saddle the motor mounts will be for a banshee.  Using the KTM motor would be like building a hybrid on top of a hybrid.  If I was doing a pure 250r frame, I would seriously consider that powerplant.

[sheerider11]

I like the idea of pt's on a setup like this because it puts the expansion chambers out of the way. I'm a big guy and most pipes still get me right above my boots if I'm really cornering aggressively. When I built my current setup and was looking at pipes I heard that the servals really didn't like the traditional mid range pipes. Guys thought if they paired some pt mids with a serval they would have this ridiculous torque monster and for reasons beyond my pay grade didn't pan out.

I LOVE the mx motor in my girlfriends bike. A stock stroke, mx port, stock carbs, PT high, vf2, pro mod trans. Bike is fun as all hell to ride. Instant power. Wheelies like crazy with paddles.

I had justin(surfrjag) on here do the porting. He did DDQ's damn near perfect curve, so I wanted that.

[bluebanshee98]

Def use the serval motor. Like Tyler said some led pipes to fit what your doing with the bike would be sweet. You could also use slp pipes for a cheaper alternative yet still make good power quickly. They worked great on JDS ported 4mil stock cylinder. Made more trq then cpi and same hp but came onto power a lot quicker. Of course the trade off is they don't rev as much as the drag pipes would.

[n2otoofast4u]

Why not build a 10mil for the duner and put the serval in the MX bike.

[trickedcarbine]

In all honesty, it would be pretty cool to see a 4mm serval with a hand fabbed 2-1 intake, 41mm PWK, and SRP pipes.

 

But stockers could suffice. Dunno, the outlaws and what not are cool, but there have been quite a few of them getting bitchin higher HP 4mil set ups lately. Why spend the whole nut and not go full balls. The beauty of the bigger serval with torquey pipes is the ability to just lug the thing. Meaning you come out of the short turn and that big table top you clear most of but still flat land or that big double, they're now that jump you are not only clearing, but wishing they were 10 foot longer.

 

Two schools of thought on riding big motors:

 

Old school, To high of HP motors are hard to ride because two strokes with that much power typically become less predictable and are on/off or peaky. The common thought is that you end up just fighting the bike the whole time and you get wore out quicker. So build a lower hp ,predictable TAME & LAME bike orrrr.....

 

New school, Things have changed, if you really plan the whole set up with a decent builder and parts, it's possible to have gobs of torque and ride the bike less aggressively yet still have the power right there to huck you over the jumps out of the turns. Build it so big it makes more torque then any 4 stroke way early on and then not have rev the piss out of it. Less fatigue, less wear if you know how to take advantage of that.

[rjayb]

Solid suggestions.  The torque comes on my 421 hard at about 7K right now.  With different pipes, what's the soonest any of you have seen a 421 serval come on and make 40+tq  When I sat with Cam on that build most of his dyno research was with drag pipes.  Is there a serval out there with slp's?  The twin to my motor that was built the following week is laegereliminator's and he's running PT's.  Hoping to see that thing in August. I'm going to go through the dyno room in a few minutes and take a look at some of these motors.

[rjayb]

^^^ That's a nice motor.