300cc bore kit for CBR 300

[dictater]

Has anyone done a bore on the 250 cbr? My CBR is at about 85k kilometers and it needs engine attention. Haven't had the shims check in a while and actually not sure if when they were supposed to be checked they ever were, I had evidence to the contrary. Something needs to be done but I have not trust in my local mechanic to do it since he trashed my D tracker last year and the local Honda shop won't do it and as far as I know either will Big wing (500cc and up I believe) which leaves the 250 and 300 in the no maintenance gap. I was wondering about finding someone to do a bore kit to 300cc, I figure if I'm going to have someone tinker with what has been a bullet proof bike for 5 years I may as well go all the way, anyone tried it?

[VocalNeal]

It would be easy if the 300 wasn't a stroked engine, not a larger bore. You are looking for an 83mm bore up kit.

 

Takegawa makes a 304cc kit https://www.thaivisa.com/forum/topic/868801-honda-cbr-300r-upgrade-from-250/

 

http://www.takegawa.co.jp/english/new_parts/1311_hyper_s_cbr_crf_e.pdf

 

Best you might get locally would be a 78mm piston = 262cc 

Edited September 14, 2017 by VocalNeal

[Neilly]

21 hours ago, dictater said:

I was wondering about finding someone to do a bore kit to 300cc

One of the guys posted the attached on TT in the CRF250L forum (same engine)...basically he upgrades your 250 to 300 using Honda parts...maybe worth emailing him

CRF 300 cc quotation.pdf

[VocalNeal]

I guess one could do both and get 350. In theory? 

[Neilly]

3 hours ago, VocalNeal said:

I guess one could do both and get 350. In theory? 

Yes you can...and it has been done

[papa al]

Where you?

"My" shop in Patts could do the rebuild.

Good; not expensive.

Honest.

I would suggest rebuild to original displacement, + the minimum rebore.

Unless you like spending.