Cylinderhead R25/3

[guest1081]

Hello

Just bought a new cylinderhead. I can see that there is a difference from the old one.
Is this not a original head ?
The new one is the one on the left.

Jesper

[guest1081]

[4Taktix]

Hi Jesper,
the left one seems to be R25/2. --> round shaped combustion chamber outline, compared to the more oval outline of /3.
In combination with a straight ( 90 °) Exhaust-port and 2-bolt Carb-Flange and 22 mm inlet diameter.
The Oil-lines then are also different to /3.
Depending on the price paid, I'd give it back.
Regards,
Sascha

[guest1081]

Hello.

Is it possible to ride with this head. It is the onlyone i have?

Jesper

[4Taktix]

Hello Jesper,
I think so, but you have to consider certain things.
You need the oil-pipes and afaik also the rocker-axles and sleeves for 25/2. These are different to /3, as the whole inner oil distribution is.
Maybe they came with the new /2-Head ? Got some pictures from top view ?
Then you require either a /2-Carb (22 mm) or you got to grind the 22mm-inlet carefully open to 24 mm to fit for the /3-Carb.
Concerning Valves/Piston clearance there is no problem, also the head-gasket, lifters and rods do fit.
What is the problem about the "old" /3-Head ?

Regards,
Sascha

[guest1081]

Hello.

The head has a bore at 24 mm inlet, so I wonder. Could this one be a unorginal?
The bike rides fine with this one mounted and a carb with 24 mm bore.

Jesper

[Rütz]

Riding is one thing... but do the rockers get oil ??

[guest1081]

Hello

They get a lot of oil. Started up without the top covers, and oil was comming fine.
Any know about the unorginal cylinderhead?

Jesper

[4Taktix]

Hello Jesper,
probably somebody already did, what I recommended above. This is not unusual.
Concerning the oil-supply for the rockers we'd appreciate pictures. So we probably can tell, if the parts-mix is OK or not.
The weak point is the supply for the rocker-axles. It is not sufficient, if they were just moistened from oil-dust on the outside.
Regards,
Sascha