For those that are looking to unlock HP and TRQ . Latest chart on top. Obviously I am still too lean for max power with the DG-R + Stock Header. I am still too lean in the upper RPM range with the full FMF system for max power..

EDIT: 4/10/15 - It looks like the below chart is not valid. The operator is sure that run was in 3rd gear instead of 4th.. I'm going back in hopes of getting the correct chart off the dyno...

Edit 6/16 - This is an old and outdated thread. Proper lidless fueling with slipon, near sea level, is with kit DJ2152, DJ140/K152 main jet, needle clip on 2nd notch down from the top(2N). With full exhaust, DJ144/K158 , needle clip on top notch(1N)..
See the proper thread below on my signature line..

 

That's a sizeable increase in torque, it actually looks like a curve now. The AFR did change but not much from 5k to 7k rpm. How does it ride now?

 

Tell me exactly what you are comparing/analyzing - The DGR curves ?

 

I wonder what's causing the FMF system to go rich under 5k compared to the DG system? I am wondering if you would make up some of the difference if they had comparable a/f. 2 lb/ft is a sizable difference.

 

Yes the FMF consistantly causes a very different AFR chart than the DGR + stock header..
The AFR with the FMF only gets lean toward the upper end - which is not good ... The 12:1 in the midrange is about perfect for power production, that's the 5N doing that..

There is more HP and TRQ available with the DGR if only I could get the AFR down close to 12:1 throughout the range - Probably a lot more HP/TRQ can be found ..

 

If I'm reading that first chart correctly, re the Tq, I'm seeing that the Megabomb/PC4 combination might have a little more Tq at the top end, but losing a considerable amount compared to the DGR near the bottom end. I'd gladly lose a little torque at the top end to gain what appears to be almost 2LbFt of torque down at the 4500RPM range. I wonder what the PC4, without the Megabomb (using the stock header) would produce for Torque - close to the stock header/DGR combination?

I do find it funny that they use the wrong label for torque measurement (Ft Lbs instead of Lb Ft.) on the charts? (http://en.wikipedia.org/wiki/Pound-foot_(torque))

 

Loss of 2lb ft and about that much in HP as well...

I am going to have to go ahead and Dyno the PC4 + stock header... I can't get it out of my head that I don't have data for what could be the best combo for HP and TRQ.. The DGR maintains stock header I.D. all the way to the muffler, that's for TRQ... The PC4 has a larger ID - so from the end of the header to the muffler is a bigger pipe - And I don't know how that will affect overall power production... I guess I'll dyno it..

 

Just test rode with the PC4 + stock header..This is the first time I've done this config as it did require damaging the stock header gasket/seal in order to remove it.. The PC4 will not slip into the stock header until you remove this seal.. I've been riding today with the DGR and wanted to compare while the DGR power is still fresh in my mind..

Low end response and power are less than DGR - as expected.. MIdrange power hits hard starting at about 5k - we are talking wheel spin starting at about 5k on hard pack clay "dirt road"... Top end power is a question mark - I couldn't make a determination - It should be better than DGR..

I suppose I had better do another Dyno run on this config..

 

Went for a long ride today with DGR.. Big power in your face with every blip of the throttle.. Offroad, on the trails, we are talking wheel spin with every blip.. It'll wheelie on power alone while spinning its' rear tire.. No, its' not like my FE650E or KX500 but it is exciting nonetheless..

 

The torque curve for both now looks like an actual curve.

Looking at the DGR AFR curve, it seems the extra turn on the screw richen up a bit below 5,750 rpms. Guess you do need a large pilot as you stated if you want to get it richer.


Also, it looks like the 5N richens up at the same point around 5,750 rpm as the 4N. From there it is richer with 5N until 6,500 rpm than the 4N, then the 5N leans out to match the 4N until around 7,500 rpm, that is strange to me.

The other strange thing I see in the DGR AFR curve is that the 5N is leaner from 7,500 rpm and up than the 4N with the same main jet, this is what you described in your first tests before the dyno. Could it be you are right and the bowl doesn't have enough capacity to feed the 5N and 136 main?

Thanks for sharing this, your dyno charts are definitely the best jetting comparison for the KLX250 that I have seen.