canuck1969
CB750 Member
All,
Just thought I would introduce myself to the forum. Just picked up a basket base 1980 Custom that will be my next restoration project. Recently finished a restoration of another 80's classic, a 1984 Yamaha XS650. I would post pics of it but not sure the die hard Honda folks want a Yamaha on the forum.
For the CB it will need a lot of work. Hoping most of it will be cosmetic but starting to see some issues to address in the electrics and engine. Changed the oil and did a quick cleaning of the carbs so they would not leak anymore and managed to get it started but ran rough on idle and very uneven heat from the exhaust headers. From burning hot to warm at best on #4 cylinder At least it started which is more that I had expected.
Ran a compression before I started it and had some lower numbers than I would like. The good news was they were withing a few pounds across all 4 cylinders and were around the 130 PSI range. After I got it started and managed to get some heat into the engine I rechecked it and 3 and 4 cylinder went up to 150 and 1 and 2 hovered around 130. Blowing some compressed air into the cylinder at tdc revealed air air coming out the exhaust on 1 and 2 so something is not right there. Good news is nothing was coming out the intake or crank case and 3 and 4 seemed sealed up. Need to do a proper leakdown test to confirm.
Did a quick valve gap check last night (will repeat it again today) and they were all around 4 to 5 thou (that is a good sign) except for #1 cylinder. It was upwards of 9 thou on the exhaust. Not alarming but again, something going on there. Will get them set correctly and see what happens. Suspect I have some build up on # 1 and 2 exhaust valves. Will do a proper leak down test and valve clearance today and report back. Keeping fingers crossed at this point.
Question on the valve clearance. Every bike I have owned I would check the exhaust and intake on TDC at the same time. The manual and clymer say to advance it 90 degrees between exhaust and intake readings. Can I not just find TDC for each cylinder and take the readings. What am I missing here??
Here are some before pics. Lets see where it ends up.
Just thought I would introduce myself to the forum. Just picked up a basket base 1980 Custom that will be my next restoration project. Recently finished a restoration of another 80's classic, a 1984 Yamaha XS650. I would post pics of it but not sure the die hard Honda folks want a Yamaha on the forum.
For the CB it will need a lot of work. Hoping most of it will be cosmetic but starting to see some issues to address in the electrics and engine. Changed the oil and did a quick cleaning of the carbs so they would not leak anymore and managed to get it started but ran rough on idle and very uneven heat from the exhaust headers. From burning hot to warm at best on #4 cylinder At least it started which is more that I had expected.
Ran a compression before I started it and had some lower numbers than I would like. The good news was they were withing a few pounds across all 4 cylinders and were around the 130 PSI range. After I got it started and managed to get some heat into the engine I rechecked it and 3 and 4 cylinder went up to 150 and 1 and 2 hovered around 130. Blowing some compressed air into the cylinder at tdc revealed air air coming out the exhaust on 1 and 2 so something is not right there. Good news is nothing was coming out the intake or crank case and 3 and 4 seemed sealed up. Need to do a proper leakdown test to confirm.
Did a quick valve gap check last night (will repeat it again today) and they were all around 4 to 5 thou (that is a good sign) except for #1 cylinder. It was upwards of 9 thou on the exhaust. Not alarming but again, something going on there. Will get them set correctly and see what happens. Suspect I have some build up on # 1 and 2 exhaust valves. Will do a proper leak down test and valve clearance today and report back. Keeping fingers crossed at this point.
Question on the valve clearance. Every bike I have owned I would check the exhaust and intake on TDC at the same time. The manual and clymer say to advance it 90 degrees between exhaust and intake readings. Can I not just find TDC for each cylinder and take the readings. What am I missing here??
Here are some before pics. Lets see where it ends up.