hi,
today i took off my 28 the engine and build on my 3oocc mc21 engine.
there was a different on the oilpump and the enginecases. The 28 had a little whole in the case, the 21 didnt.
Can i take the 28 oilpump to the 21 enginecase if i will close the little whole in the pump? or i need an 21 oilpump? will it fit to the 28 wiringloom?



thanks
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nsr300se rs250r´05 ns-1rr

[img][/img]
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nsr300se rs250r´05 ns-1rr

Hi mate the engine in your photo is not an MC21 as the 21 has the same oil feed to drive side main bearing.It looks to me like an MC18 SP why don't you blank it off all together and go pre-mix (you will need to jet up)

Your MC21 cases are probobly from an earlier version of the MC21. Honda modified the MC21 cases in later life to provide oil directly to the one or other of the crank bearings. This is why the MC28 crankcases have this oil feed.

All my MC21 cases only have the single oil way. I dont think they got changed untill 1992 on the MC21.

Anyway. I would try and track down the right early MC21 oil pump to go with those cases if you want to continue to use a pump.
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If I have to take the carbs off once more...

so,
today i closed the 2nd Channel on the 28 Pump with 4mm screw. Hope it works, will see next Weekend.

[img][/img]
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nsr300se rs250r´05 ns-1rr

German engineering hey?
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If I have to take the carbs off once more...