measure twice, cut once can also mean read bills resto guide twice then put things together once.
1967 cb77.
before i started bike was running but rough.
compression was at 110 on both cylinders, but if i put a teaspoon of oil in and tried again it shot up to 150. so i assumed the rings should be changed.
ordered rings but they were too thick then got another set that seemed ok.
after completely taking everything apart and then putting in new rings.
bought new exhaust, cables, tires, rims and various other doohickies i finally got everything back together and tried to start.
wouldn't start.
found lots of problems.
1. oil was leaking out of front two studs at top of head.
2. compression on right was 90 and on left 30.
for number one i realized I used lock washers and not the proper copper crush washers. so i put the proper ones on and started torquing things down again and wouldn't you know it one snapped.
so i got a couple on order and i guess i'll have fun figuring that out.
next the really low compression scares the crap out of me so i tried the leakdown test by blowing air into the spark plug holes.
on the right side(90 psi side) it was leaking out of the exhaust port at what i thought was tdc.
as i turned over the engine past it it would stop leaking.
left side it would leak from exhaust as well and no matter where i turned it it would leak to various degrees.
so then i started thinking back to where my i put the cam chain back on and remembered lining up the mark on under the points cover with tdc but im pretty sure i'm 180 degrees off.
as i watched the intake port on right open when i got to the next tdc mark the cam marker was pointing straight down.
now i never got to the tune up part of adjusting points and valve clearances so i decided to check the valve clearance and found on the left side there was no clearance so i'm hoping that's why air constantly leaks out of that exhaust port because its partially open.
so here's my questions.
1. 1 to 100 how stupid am i
2. any advice on replacing a cylinder stud. the broken one looking down on the engine towards the front of the bike is the lower left one
3. am i correct in if the cam chain was off by one full turn it would cause most of my readings.
4. would installing the proper crush washers eliminate the oil leak on front two studs or can it be something else. i remember installing two little o rings on two of the studs. hope it was the proper two.
also cant get the neutral light to work but thats another day
low compression, oil leak, and i'm an idiot
just to be sure should be at T on stator behind the points the line is straight up the O on the cam chain gear straight up. all during the compression stroke? and how are you sure you\re on that stoke. also noticed i think i had the top three gaskets wrong. i had fibre/metal/fibre and how do you make sure the metal is in correct orientatio. thanks and i guess one more question. when the new cylinder rod arrives , just turn it it till it bottoms out? torque?
With the rotor at "T" the crank is set for the right side compression.
With the points cam line at top you are set to install the chain. Then rotate the crank so the points cam line is down (T) and set the right side valves. Open gasket, metal gasket, closed gasket with the 2 small oval holes toward the exhaust. ..............lm
update:
thanks LM your simple instructions did the trick as far as cam setup put my replacement engine stud in and its too long. tried just using a regular nut but i have some seepage so i'm going to cut of a bit and put the proper acorn on her. still have a little leak coming from tack drive area and i'll figure that out set valves/points timing and she starts right up. now i had some free time this week so decided to do what i should have before anything else. i read every post in the 118 pages of the motor section. took 4 days found a lot of great info. what i found that makes me realize i need to open everything up again is that you cant just install new rings even if the cylinders and pistons are fine. you need to hone which i did not. never realized how important seating the rings were. so im getting a honing kit this weekend and will do that next also have 8 new crush washers that need to get on there.
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