Hey, figured it would be best to contain things to a single thread as I modify my bike. You guys have already seen my Kickstarter video, now for more!

I actually did the BB351 in August (#426), but I made a video about it. I also made a short one discussing why I think the KLX is an amazing bike (pretty much it comes down to how modifiable it is).

Here's some pictures:




Then the vids:

 

I'm always blown away by the side by side pics of the 250 and 351 barrels.
No wonder it's the best power mod available...

 

Figured I'd post a bunch of pics from the past week. I'm still working on the video for the steering stabilizer, I realized I needed more info on its adjustment settings.


New Chain Guide, and Stealth Sprocket


EBC SM 6329 Front Rotor.


Zeta Engine Plugs and Starter Motor Cover


Zeta Oil Filter Cover and DRC Hoses


3000 Miles of Grime on the 351's piston. (Sent head out to get ported/Kibblewhite Valves)


Grimey Head.



Working on the Bike inside. Airbox removed to get to the shock, which is with Moto-Pro.


Works Connection Frame Guard and Oil Plug, Zeta Brake Clevit.
Later today I'm going to repaint the side cases for the engine.


Zeta Brake Reservoir Cover.


Works Connection Caliper Guard



16t countershaft sprocket.


Zeta Sprocket Cover.


Works Connection Left Frame Guard


Zeta Top Clamp from the Front, Note the Key Mounting.



Top Clamp From the Rear. The thing on the steering stem is for the stabilizer, though I will have to find an alternate handlebar clamp from Scotts, since the one for the KLX doesn't fit the Zeta top clamp.


Magura Hydraulic Clutch (For a KDX220, strangely it fit perfectly.)


TM36-68


ATACC, if anyone buys this be sure to tell them to set the base temp to 40'F.


Tusk Cap for Clarke Tank


License Plate Stash Box (I use it for insurance/reg)



EBC clutch kit. This is mainly so I can use synthetic oil.


Scott's Rear Rotor Guard. Advantage of having an early KLX.

 

If you want to have the most modified klx351 in the world, please do some webcams, head porting, larger exhaust valves, and put that bad boy on the dyno!

 

Head porting and larger valves is currently being done by Bill Blue.

I am really hesitant with the webcams, since porting, shrouding, and the Q4/Megabomb all serve to move the powerband towards higher RPM.

There's a guy in Canada who has done all the things for engine performance. Pulled his baffle and even his backfire screen I believe. James Damphouse is his name I think--talks to me all the time on YouTube. He hasn't done a Dyno, but somehow can wheelie in 3rd. https://www.youtube.com/channel/UCjF...daUGdLErGBFmRA

I will do a dyno at some point this summer. I'm hoping for 30hp from my setup (note that I'm at 6000 feet, 30HP=35HP at sea level). I believe this engine could potentially put out a little over 38, but that would be extremely difficult.

One more thing on the webcams: I was using an engine tuning program a while back, and in this software you can predict the effect of cam changes on an engine's performance. The KLX's cams are designed to make the powerband plateau fairly early, so that you aren't waiting until 6000 RPM before you have the power you need.

All engines (at least those practically used) have a set timing which is why we have 'optimal powerbands'. If variable timing engines were ever a thing then power curves would just be a diagonal line.

Thing is, you can only have your set timing engine intersect the optimal diagonal at one point--the inflection point if anyone is mathful. The rest curves away wasting potential power. Putting it earlier means less maximum power, but more power at low RPM. Putting it later means more maximum power, but lugging your engine all the time.


Anyway, the Webcam 101's should add about 2hp at 10,000 RPM (where I calculated), but cut around 1 from the max torque.

From interpreting other people's Dynos I have this as a rough estimate of performance improvement from other mods:

Aftermarket Exhaust: ~3HP
Porting, Large Intake Valves: ~3HP (from 351cc)
K&N Filter, Opening Airbox: ~2HP
36mm Carburetor: ~3HP
351BB: ~8HP

Adding in the 17 base gets a rough total of 35, which is where I get my predicted number from.

 

Yeah I have the same thoughts an apprehensions too, hence why I have only done 351 kit and tm36-68 carb and a slip on (which by the way on my dyno results showed a hp rating of 28.9 or 29.8 don't quite remember, still being way too rich up top). This is a 2000ft above sea level.

I have a firm belief that ported head, larger valves, Australian ignition curve (large thread on that around here too), powerbomb header, and webcams should net close to 36 horsepower.

Having the 351, I can tell you torque is abundant, even with a 15 tooth front, a loss in torque for a gain up top would be very beneficial (at least to the supermoto version, probably less to the dual sport version). Looking forward to your results and testing.


One more thing, drilling the case vent to 1/2" I think? should increase breathing with the new motor and will increase power by 1/2 to 1 horsepower.

 

Good you mentioned that, I have my engine sitting on a table right now and this would be easy to do.

Last time I went offroad mid december, I swapped the front sprocket to a 13. Easy enough to do I think. My brother stalled with a 14 tooth on one part, but that may have just been the snow. If anyone's curious:


Supermoto stuff will likely be next year. I figure rims, tires, tubes, rotors (if I'm feeling lazy), preload adjusters NA Metal Craft : Front Suspension Initial Adjuster [NMCD-020], and whatever else would be $2500.

 

It would be just about as expensive for me to go to a dual sport set up, roughly $1700, rotors wheels tires etc...So I bought a plated drz400e all modded up for $1800 haha! best of both worlds.

 

I tore my bike down to the frame and was going to sandblast/paint it, then snow. Still waiting on Motopro to return my suspension, and porting/oversized valves from Bill Blue.

Hopefully will get to go for a ride soon. Here's the pics from this week:


Sharkfin next to the OEM caliper mount.


NA Metal Engine Mounts next to the OEM ones.





Engine side cases, getting ready to paint.


Then this weeks video.

 

Sorry about taking so long to update, but here's the past few weeks photos and vids.


Sidecases Painting


Krieger Cam Chain Tensioner against the OEM


My handlebars look like a deer rack.


Painted Swingarm plus the Hot Foot Moto chain slider.


9 Bags of sand to remove all the paint from the frame.


Painted Engine Parts waiting to be cured.


Engine Going Back Together




EBC 6329SM Rotor after new paint job


Comparing paint colors


Ported Head intake


Kibblewhite valves (+1mm intakes)


Ported Head Exhaust



OEM header on the FMF Megabomb



Sandblasting the Frame


Engine parts for dinner...


Frame Painting


Hub Paint


Vapor Comp



I thought you all might be curious, I weighed a few parts while doing this. The bare frame as pictured weighs ~28.5lb, and the engine weighs ~77lb.



Here are the videos I made:


And some more from my most recent trip: