Frustration

[cribbs74]

Gents,

Been chasing an ignition issue, lately a funny problem has been happening. If I set the timing dead on per LM's instructions bike runs and starts fine. I go for a short test ride shut the bike down, leave it overnight. Get ready for work in the morning, try and fire up the bike and it fires on the right cylinder only. I check for spark which is good so I re-check timing and it's off. By a good bit too.

My points plate screws are good and tight as well as the point hold down screws nothing has shifted but why my timing change?

I observed the other day a small intermittent blue spark arcing across from the condensors to the top engine hanger. I assumed that may be the problem but everything is tight and free from corrosion. I did an Ohms check from the condensor case to ground and got .002 ohms or something like that. I did notice in my Clymer manual that there was a picture of a ground strap connected to the condenser. The pic was of a CL72 and mine is a 1966 CL77. My bike never had that strap before I started the resto/refurbish. Not sure if that's the problem anyway.

Anybody come across this before?

[davomoto]

Sounds like you have a bare wire at the condenser. I'd remove condeser and look for the issue there. I know that the CB77s have a ground strap, but my 67 CL77 does not. Perhaps because the top motor mount is rubber, it won't support a ground?

davomoto

[LOUD MOUSE]

The CL72 manual I have shows many things that we didn't get on our CL72 bikes and some pics using the CB72 bike. Things we didn't get: Round bowl Power Jet carbs, Gas valve with the carb tubes on front rather than rear and shorter Air Filters. What page do you see the ground strap?. ...........lm

Gents,

Been chasing an ignition issue, lately a funny problem has been happening. If I set the timing dead on per LM's instructions bike runs and starts fine. I go for a short test ride shut the bike down, leave it overnight. Get ready for work in the morning, try and fire up the bike and it fires on the right cylinder only. I check for spark which is good so I re-check timing and it's off. By a good bit too.

My points plate screws are good and tight as well as the point hold down screws nothing has shifted but why my timing change?

I observed the other day a small intermittent blue spark arcing across from the condensors to the top engine hanger. I assumed that may be the problem but everything is tight and free from corrosion. I did an Ohms check from the condensor case to ground and got .002 ohms or something like that. I did notice in my Clymer manual that there was a picture of a ground strap connected to the condenser. The pic was of a CL72 and mine is a 1966 CL77. My bike never had that strap before I started the resto/refurbish. Not sure if that's the problem anyway.

Anybody come across this before?

[cribbs74]

My mistake Loud mouse, I went home and looked at my manual and it was on page 124. Which is the CB72/77 section.

I went home and retimed the engine. Everything was spot on, fired it up and ran it up and down the street a couple times. Parked it and just for grins checked my timing again. It was off again yet it still fired up and ran great. So I thought maybe since it was hot I would check it after it cooled down.

This morning I decided to take it into work. Sure enough if fired up first kick ran fine. pulled out the driveway rode a couple blocks and lost spark on the left cylinder. Did a quick u-turn and rode back to the house on one cylinder lost the right cylinder about 200 feet from the house and coasted into the driveway.

I didn't have time to check the timing, but I am sure it is off. Davo the condensor is no longer arcing to the hanger. Not sure what caused that, but my wiring is sound with no bare wires. I have strong spark on both sides it's just the timing goes haywire after It's set and locked down and yes I am aware that the timing changes when the screws are tightened.

It has to be something mechanical, but I cannot figure out what unless the rivets are loose on the sprocket and causing my cam timing to change. The timing should not change drastically after 5 mins of riding.

[LOUD MOUSE]

Would ya check for a loose/wobbles points cam?. ...........lm

My mistake Loud mouse, I went home and looked at my manual and it was on page 124. Which is the CB72/77 section.

I went home and retimed the engine. Everything was spot on, fired it up and ran it up and down the street a couple times. Parked it and just for grins checked my timing again. It was off again yet it still fired up and ran great. So I thought maybe since it was hot I would check it after it cooled down.

This morning I decided to take it into work. Sure enough if fired up first kick ran fine. pulled out the driveway rode a couple blocks and lost spark on the left cylinder. Did a quick u-turn and rode back to the house on one cylinder lost the right cylinder about 200 feet from the house and coasted into the driveway.

I didn't have time to check the timing, but I am sure it is off. Davo the condensor is no longer arcing to the hanger. Not sure what caused that, but my wiring is sound with no bare wires. I have strong spark on both sides it's just the timing goes haywire after It's set and locked down and yes I am aware that the timing changes when the screws are tightened.

It has to be something mechanical, but I cannot figure out what unless the rivets are loose on the sprocket and causing my cam timing to change. The timing should not change drastically after 5 mins of riding.

[cribbs74]

Will do Loud Mouse, I will get back with you on that. Headed home from work now.

[cribbs74]

Loud Mouse,I lost the charge on the battery while re-timing the bike to see if the points cam is wobbling while running. It's on charge now, however I can say I am able to move the point camshaft lobe physically in all directions about an 1/8 of an inch. It seemed like a lot, but I'm not sure what's normal freeplay.