DRZ462: Living with it

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Torque Curve

Race Dog
Joined
Aug 13, 2009
Messages
749
Reaction score
9
Location
PE
Bike
NER-A-CAR
Background
My bike seized the inlet camshaft in August 2012 and I decided to rebuild the motor to 462cc. This job was documented here:

https://wilddog.net.za/forum/index.php?topic=105665.0

New parts included the following:
+4mm Cylinder Works barrel with Vortex forged piston
+4mm Hot Rods crank shaft and con-rod
Hot Rods side bearings
Wiseco stainless inlet and exhaust valves
Kibblewhite valve stem seals
All bearings and seals
Used parts:
Head from 2001 DRZ400E with inlet and exhaust camshafts. The valve seats and -guides, cam journals and bearings were all meticulously measured and found to be as good as new so I installed the head with confidence. Thanks again to Kenzogs for this fantastic gift!

I decided to do such an extensive rebuild due to the volume of metal particles I found in the motor and oil screen. To get rid of any contaminated parts I decided to replace all bearings and seals. The +4mm stroker crank was a nice-to-have as the original crank measured up fine.

Running in:
The bike literally started with the first touch of the button. The first 100km was covered on back roads where I could do some runs up to 2/3-throttle and a quick off-road ride had to be squeezed in at the end of that day. I drained the oil and cut open the filter because I was curious to see how much wear occurs during engine run-in. I replaced the oil with Castrol Magnatec 10w40 and installed a new filter. The oil screen was also removed and found to be clean. The extra power of the 462cc motor was obviously very noticable, but I decided to wait for the motor to loosen up before I started comparisons with a std engine.

The next 200km was spent trail riding mostly single track and a few short sandy stretches. I replaced the oil and filter again and found as much metal dust as at the first 100km oil change. During the first 300km's I kept below 100km/h and avoided wide open throttle.

The next 400km again involved mostly trail riding, but I upped the pace a bit to the point that the worn tyres on the bike started annoying me. So at 700km into the new motor I replaced the oil and filter again and found less metal dust than after the 100- and 200km changes put together. I prefer trail ride run-ins due to throttle positions that vary all the time so those rings are forced onto the sleeve better than on a long low-load road ride. I think a trail ride with frequents stops and wrong turns as one does allows more cooling off time for new tight motor.

The final stage of what I consider run-in mileage was a 550-odd km trip: PE, Elands, Baviaans, Willowmore, Steytlerville, Grootrivierpoort, PE. The 86km cement road from Willowmore to Steytlerville was done at 115km/h with a few bursts up to 130km/h.
The average fuel consumption for this trip was 17km/l which is = to what I got on my first DRZ400 when I did the same ride some 2 years ago. Oil and coolant gets checked and air filter gets washed and oiled at the end of each day's riding.

Performance:
I'm comparing this DRZ462 to how it behaved as a std 400cc and to my previous DRZ which I bought new and rode for 7500km. All bikes run 14/47 sprockets and 130/80-18 rear tyres.
DRZ's are known for their even power delivery throughout the rev range and their ability to pull comfortably from low down even in 5th gear. The increased capacity adds more power this motor, but the extra 4mm stroke of the crank makes the motor even stronger low down. My std DRZ's could power wheelie in 2nd and with a lot of encouragement I could do in 3rd, but not with consistant enough results to make it worth while. The 462-motor will lift the front in 3rd gear regardless of where the revs are and in fourth gear riding near  the powerband the frontalso  lifts strongly - all of this without the clutch!
There's a short stretch of road where my riding buddies and I often had a last dice on our way home from the trails. We pull off at a traffic light and barely reach 130km/h before having to brake hard to make the turn into my street. (Sorry officer). The 462 ran up to 140 well ahead of the turn-off so that I had more than enough time to reduce speed for the turn. For normal riding around town the 462 feels like 400, except that everything happens easier and the 462 gets the same job done with far less revving of the motor.

To follow: Carb set-up, balancer shaft, exhaust, gearing off-road, sprocket change etc.


 
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