CR 125M cylinders and heads

[cr4ever]

Honda guru's, can you please explain:
1. What is the difference between the 74 optional cylinder ( with the extra transfer ports) and the 75M1  76M2  77M3 barrells?
2. How can you tell which is which?
3. Are there any differences between the heads for all of these, and how do you tell which is which?
4. Which ones are OK for pre 75 on a 74 model?
Many thanks....

[bigk]

'74 std 8 port & '75 std 9 port (optional for '74) & heads, are physically smaller than '76/'77 M2/M3. You can fit the '74/'75 cyls to '76/'77 bottoms but not the other way around unless you machine the cases to take the bigger cylinder skirt. '76/'77 cylinder & heads are not legal for pre '75, they stand out like dogs balls and are very obvious.
Cheers,
K

[cr4ever]

BigK, Thanks very much for clearing that up.

[Freakshow]

Dogs balls   

now if you saw these two brothers, you'd realise how funny that really is   

you crazy nude nuts, Robby.

[cr4ever]

Dog's balls eh Marshy, we'll remember that at Days Rd in a couple of weeks!
( I'm just checking that nude nut #2 has a legal cylinder/head on the M1- I know mine is because it's still my original from 1974 but his bike has an unknown history. Mine was ported in 1975 by a Coorong fisherman called Bob Rush who had a porting set-up in his lounge room- ever hear of him these days? He owned a very trick CR125 - I remember Gary Wooding riding it at the Barmera charity meeting in January 76 and I only just held him off on my CR250. Won a toolbox - and I've still got it! Anyway whatever he did to my ports seems to be OK, it still goes pretty well eh!)

[Freakshow]

hey i didnt say dogs ball BiG K did, i was the nude nut.

any how...... Im guessing thats why #2 bike runs shit. 

Actually its probally the rider, but im guessing its the head or barrell, im guessing your head has  been squished and cc'd you cant just put a Cr125 on alchy and expect it to run fine, im sure they were only 8:1 out the box so your not getting any benifit out the alchy at that on bro bike if his out of ther box.  maybe why its not running out either on the pipe.

the plot thickens. 

after next race, pull em both down and cross check the heads and then check if anything has been skimmed off the barrell heights, im only guessing but im saying there differant.   For 2 bikes supposed to be on the same specs, they are light years apart. 

[cr4ever]

We'll see at Days Rd! He's been complaining about the gears not shifting easily out of 2nd at both meetings, I blamed his monster boots as it felt Ok for me using my 35 year old Sidi boots , but finally found a bent shift shaft causing it to jam- it got a lot more bent at Acusa Park after he stuck it into the tyres trying to outbrake you into the top corner. For the last race he did 2 laps before he got it out of 2nd gear! Your right I'll check them both out and compare them when I pull them down for a freshen up before Griffith.

[Freakshow]

pity he didnt bin it in the Allpowers, could have used them points back after my Chain DNF........

[cr4ever]

the allpowers points are pretty close, what bikes are you going to ride this time?

[Freakshow]

What ever is closest to the door.  Love to bring the Dt1 out for a fang, but not back together yet, but well see how it pans out