Mitaka and Vertex Pistons DT 125
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JanBros
- Avgas Sniffer
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maccas
- Oil Injector
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- Joined: Mon Sep 07, 2009 8:33 pm
- Location: east yorkshire
Finally got some pics of the vertex pistons:
Compression height is pretty close to the stock kr piston, I still haven't had chance to measure accurately but a quick measure the other day gave 0.5mm higher compression height.
The cut outs for the transfers below the gudgeon pin are a bit smaller than the kr piston and could do with opening out a touch to match the barrel better but they aren't too far off.
To run them on my barrels that are on the bike I will have to use a thicker base gasket as I have a 1mm squish.
Dan
Compression height is pretty close to the stock kr piston, I still haven't had chance to measure accurately but a quick measure the other day gave 0.5mm higher compression height.
The cut outs for the transfers below the gudgeon pin are a bit smaller than the kr piston and could do with opening out a touch to match the barrel better but they aren't too far off.
To run them on my barrels that are on the bike I will have to use a thicker base gasket as I have a 1mm squish.
Dan
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maccas
- Oil Injector
- Posts: 877
- Joined: Mon Sep 07, 2009 8:33 pm
- Location: east yorkshire
Modified the vertexes today, cut them down by about 2 mm and opened out the cut out in the rear of the piston to match a KR piston, before I did that I took some measurements and weighed the pistons.
Both bare pistons
Stock KR (worn though):
Vertex:
Vertex gudgeon pin:
KR pin:
Comparison pic of pins:
Vertex rings:
Vertex clips:
KR clip:
Post modification:
Weight is now 141.82 g.
Compression height is 29.90mm (centre of pin) but the piston has a chamfer around the edge so the actual dome of the piston is a bit higher than where the timing edge is, so fitting one of these pistons will reduce squish by about 0.8mm at a rough guess so a thicker base gasket is needed i would say.
Dan
Both bare pistons
Stock KR (worn though):
Vertex:
Vertex gudgeon pin:
KR pin:
Comparison pic of pins:
Vertex rings:
Vertex clips:
KR clip:
Post modification:
Weight is now 141.82 g.
Compression height is 29.90mm (centre of pin) but the piston has a chamfer around the edge so the actual dome of the piston is a bit higher than where the timing edge is, so fitting one of these pistons will reduce squish by about 0.8mm at a rough guess so a thicker base gasket is needed i would say.
Dan