I have taken delivery of a DRP 152cc engine based on a bored up DRP 120cc motor and fitted it to my Dax. Thought I'd post up a review for anyone who is interested.
I have split the review into three so I can update it as it runs in. I have also listed the spec and bits I am running it with for reference.
Spec:
|
Bore |
59mm |
|
Stroke |
55.5mm |
|
Bottom end |
Stock DRP with strengthened gearbox |
|
Head |
Stock head (27.5mm inlet valve), TJR Fondled and Cajoled |
|
Cam |
Takegawa R20 copy |
|
Carb |
Mikuni 28mm Flatslide with home made manifold |
|
Exhaust |
Takegawa Bomber (borrowed from my Monkey, short Kitaco Supertrapp going on it) |
|
Gearing |
17 front sprocket. 36 rear on 12” wheels. |
Initial Review
Posted 25/4/05
Fitment
Was straight forward to fit even though I was converting from 6v as the
electrics are the same as ZS108s I believe.
DRP convertor loom and bish, bash,
bosh. And I HATE electrics !
Only needed to space down the footrests (M10 threaded rod connectors do the trick nicely if you’re stuck)
Power
Difficult to judge at first with only about 40 miles on the engine and not being out with other monkeys. It is not Takegawa 124 type revvy power at all. The best way I can describe it is the difference between the 125 2 stroke Motocross bikes and the comparative (250cc) 4 stroke bikes they race against. The grunt is low down and pulls you really well without you feeling like you are being ripped along. I’ve geared up once already from my original gearing and will go up again. I spent almost all of the 30 or so miles I did in 4th gear. Jetting running rich too to protect the motor during run in.
Big bike speedos are not necessarily more accurate than monkeys (see MCN speedo test of about 4 years ago) but my brother was following me on a 1550cc Harley Gayboy reading a steady 70mph as I pulled away past (amazed) traffic. True speed was probably more like 60-65 as I was not giving it revs due to the run in. Won’t be a speed demon though due to the Ape Hanger bars making me like a sail in the wind.
Definitely quicker than my brothers tuned 114cc monkey though (did about 2 miles out with it), even when I had a stupidly big jet in it which was causing it to splutter past ½ throttle.
Gearbox
As reported previously basically. When moving the gearbox feels very positive and solid, when stopped it can be a bugger to change down and get into neutral. This should wear in though after 500 miles or so, hope to do at least 200 over the IOW weekend.
Summary
Overall for a
tight motor I am .
The grunt makes it easy to ride quickly as you
don’t need to be precise keeping it on the revs like a Taky. Also feels
like a very solid motor and not at all fragile. Watch this space ..........
Review After 500 miles
Power
Gearbox
Reliability Issues
Review After 1000 miles
Power
Gearbox
Reliability Issues