[pampadori]

hello, i have a 72 cb750 with what i was told was 12.5:1 830cc pistons and yoshi cam and heads. It also has a Dyna Ignition.

1st question, i get smoke coming out of the crank vent. what are some causes, is it something to worry about, and is there a oil trap/separator build into the vent system?

kicking the engine over, it seems to have fantastic compression. i have not performed a compression test yet, as the bike runs pretty good and makes very good power.

2nd question, with the dyna ignition, i have attempted to set the base timing, but it only wants to stay running when i have it almost all the way advanced (to the end of the adjustment). i have a manual but the marks on my bike for timing seem to be a little different. so i thought i might ask for advice here.

Thanks in advance for any replies.
Shaun

 

[joe c]

smoke, or steam from the vent is normal.

full advance on the timing is fine. it probably needs it.


jc

jc

"tex, if your bikes a cheater, its not a very good one"

 

[pampadori]

thanks! i was worried that i had too much blowby.

 

[Geeto67]

quote:
thanks! i was worried that i had too much blowby.

if you were getting too much blow by it would be pressurizing the crank case and you would get lots of oil coming out the breather. Condensation forms in these cases when the bike sits, sometimes that just burns off.