Dianne's C77

DianneB · Post by **DianneB** » Sat Aug 08, 2015 5:58 pm

Battery voltage is fine - recharge it after every failed start attempt - lots of spark. It almost behaves as if I have a stuck intake valve. Will check the valve settings next week.

LOUD MOUSE · Post by **LOUD MOUSE** » Sat Aug 08, 2015 6:01 pm

Compression both cylinders?
Spins really fast?
These engines are famous for "I got it running and now what"?
I think you will find what the problem and get it to start COLD again. ................lm

DianneB wrote:Battery voltage is fine - recharge it after every failed start attempt - lots of spark. It almost behaves as if I have a stuck intake valve. Will check the valve settings next week.

DianneB · Post by **DianneB** » Sat Aug 08, 2015 6:26 pm

LOUD MOUSE wrote:Compression both cylinders?
Spins really fast?

Not really fast - there is some compression but it isn't great. Most concerning is that when I crank it over slowly using the kick start, it sounds like I am hearing "breathing" through the carb from both cylinders.

Maybe it is time to give up getting it running for this year and do a complete tear-down and rebuild. (I have been ignoring other work for too long!)

LOUD MOUSE · Post by **LOUD MOUSE** » Sat Aug 08, 2015 8:22 pm

Check the valve settings first. ................lm

DianneB wrote:
LOUD MOUSE wrote:Compression both cylinders?
Spins really fast?
Not really fast - there is some compression but it isn't great. Most concerning is that when I crank it over slowly using the kick start, it sounds like I am hearing "breathing" through the carb from both cylinders.

Maybe it is time to give up getting it running for this year and do a complete tear-down and rebuild. (I have been ignoring other work for too long!)

DianneB · Post by **DianneB** » Mon Aug 10, 2015 3:09 pm

Checked the valves - didn't have the clearance number with me in the shop but each rocker is slightly loose at TDC on the compression stroke.

I replaced the petcock that was causing me trouble with a brand new all-brass valve and a fuel filter. Found some fine debris in the float bowl so I took the carb off, took it apart, and blew out all the passages with compressed air before putting it back together and back on the bike.

I checked the cam timing by aligning the T mark on the rotor and the slash mark on the points cam was at the top and perpendicular to the cylinder bore.

Pulled both spark plugs and checked for spark - good spark at the right time (F mark on the rotor). Plugs look clean and maybe slightly damp from gas.

Still wont fire up!

I am about at my wits end on this motor! I am about ready to drop it off the bike and start a rebuild instead of waiting for winter - GRRRR!!!

The only thing I can think of is burned valves (1 or more) but that doesn't explain why it ran on Wednesday and wouldn't start on Friday! I have been around engines my whole life but this one has me puzzled! Maybe I am missing something ubber simple or maybe it is just f'ing with me!!!

sarals · Post by **sarals** » Mon Aug 10, 2015 3:48 pm

Is it for sure getting gas?

G-Man · Post by **G-Man** » Mon Aug 10, 2015 4:54 pm

Is the gas fresh?

I had a little Kawaski gas-powered drilling machine that I had stored for a month or so. It just refused to run until I had poured out the gas and started with fresh. With fresh gas it fired up straight away.

G

DianneB wrote:Checked the valves - didn't have the clearance number with me in the shop but each rocker is slightly loose at TDC on the compression stroke.

I replaced the petcock that was causing me trouble with a brand new all-brass valve and a fuel filter. Found some fine debris in the float bowl so I took the carb off, took it apart, and blew out all the passages with compressed air before putting it back together and back on the bike.

I checked the cam timing by aligning the T mark on the rotor and the slash mark on the points cam was at the top and perpendicular to the cylinder bore.

Pulled both spark plugs and checked for spark - good spark at the right time (F mark on the rotor). Plugs look clean and maybe slightly damp from gas.

Still wont fire up!

I am about at my wits end on this motor! I am about ready to drop it off the bike and start a rebuild instead of waiting for winter - GRRRR!!!

The only thing I can think of is burned valves (1 or more) but that doesn't explain why it ran on Wednesday and wouldn't start on Friday! I have been around engines my whole life but this one has me puzzled! Maybe I am missing something ubber simple or maybe it is just f'ing with me!!!