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How to run a CB77 without a battery?

Charging System, Wiring, Lighting
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1204_cb77
honda305.com Member
Posts: 27
Joined: Wed Mar 06, 2019 1:55 pm

Post by 1204_cb77 » Tue Apr 30, 2019 7:10 pm

Well! Good news and bad news :)

I got the bike running and running really well! But, the right cylinder is having intermittent spark and fouling out plugs. I pulled the right plug cap when it was idling and it has a good spark, but it isn't very consistent with the left side which is running like a champ!

Ive swapped the right coil with another unit, different condenser, swapped the left spark plug boot and cable over, new plug adjusted per specs and still having issues.

The cylinder is getting gas, carbs are clean, bowl is full but it keeps having intermittent spark. Making it hard to ride obviously and can't get it passed 1/2 throttle until it starts bogging. BUT, I can rev it to the moon just fun when sitting. It's all under load while riding that it bogs out as I am loosing spark. I can hear the cylinder drop when I twist the throttle and the left exhaust is much hotter then the right.

Ive got 12v at the points and at both coils...I am thinking possibly the stator is giving me grief......

Thoughts?

LOUD MOUSE
honda305.com Member
Posts: 7817
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Post by LOUD MOUSE » Tue Apr 30, 2019 8:02 pm

Years back a feller had the same problem.
After much fault finding it was a POOR CONNECTION of the BLACK LEAD to that side coil.
????????????????. .......lm


1204_cb77 wrote:Well! Good news and bad news :)

I got the bike running and running really well! But, the right cylinder is having intermittent spark and fouling out plugs. I pulled the right plug cap when it was idling and it has a good spark, but it isn't very consistent with the left side which is running like a champ!

Ive swapped the right coil with another unit, different condenser, swapped the left spark plug boot and cable over, new plug adjusted per specs and still having issues.

The cylinder is getting gas, carbs are clean, bowl is full but it keeps having intermittent spark. Making it hard to ride obviously and can't get it passed 1/2 throttle until it starts bogging. BUT, I can rev it to the moon just fun when sitting. It's all under load while riding that it bogs out as I am loosing spark. I can hear the cylinder drop when I twist the throttle and the left exhaust is much hotter then the right.

Ive got 12v at the points and at both coils...I am thinking possibly the stator is giving me grief......

Thoughts?

1204_cb77
honda305.com Member
Posts: 27
Joined: Wed Mar 06, 2019 1:55 pm

Post by 1204_cb77 » Wed May 01, 2019 9:59 am

LM, thanks for the response.

After I posted my previous message, it dawned on me that I had my 12v going from the left coil then jumping over to the right.

I pulled that apart and make a (Y) split off the 12v lead going directly to both coils. Guess what, it fixed it and ran amazingly. But I had it wired up to an old coil still.

So, decided ok its fixed I'm going to replace the right coil with the new one and call it good. Performed the swap and back to the same issue :(

Today I will trace down my 12v lead and figure out what the hell is going on. But man oh man do these 305's move!

I am still trying to figure out if the coil holders need to be grounded to the frame and/or if the front right ground strap gets attached to my right side condenser mount. Other then that we have good spark and this baby starts immediately first kick!

Thanks all.

LOUD MOUSE
honda305.com Member
Posts: 7817
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Post by LOUD MOUSE » Wed May 01, 2019 10:34 am

The Strap from the Front Top Engine Mount Bolt does ground at the Condenser and will ground the Left Coil through the Frame at the Mount Bolt.
Scrape a little paint off each coil so they will Ground to the Brackets and 12V to "+". . ..................lm
1204_cb77 wrote:LM, thanks for the response.

After I posted my previous message, it dawned on me that I had my 12v going from the left coil then jumping over to the right.

I pulled that apart and make a (Y) split off the 12v lead going directly to both coils. Guess what, it fixed it and ran amazingly. But I had it wired up to an old coil still.

So, decided ok its fixed I'm going to replace the right coil with the new one and call it good. Performed the swap and back to the same issue :(

Today I will trace down my 12v lead and figure out what the hell is going on. But man oh man do these 305's move!

I am still trying to figure out if the coil holders need to be grounded to the frame and/or if the front right ground strap gets attached to my right side condenser mount. Other then that we have good spark and this baby starts immediately first kick!

Thanks all.

1204_cb77
honda305.com Member
Posts: 27
Joined: Wed Mar 06, 2019 1:55 pm

Post by 1204_cb77 » Wed May 01, 2019 10:47 am

Awesome, thanks LM. I think that may be why it ran on both cylinders before I swapped back to the other coil. It was pretty scraped up and had a lot of exposed metal on it...Hard to say. But I plan on getting this beast wrapped up today. I still can't believe how torquey and quick these bikes are!

Jetting is solid with the pod filters. Electrodes are a nice milky brown and no pop on decell. Need to adjust the clutch a bit still but we are up and running with full LED lighting and kick only. I'll be sure to report back my findings.

Cheers!

LOUD MOUSE
honda305.com Member
Posts: 7817
Joined: Mon Aug 15, 2005 8:23 am
Location: KERRVILLE, TEXAS

Post by LOUD MOUSE » Wed May 01, 2019 12:55 pm

I look forward to receiving good news!. .............l,

1204_cb77 wrote:Awesome, thanks LM. I think that may be why it ran on both cylinders before I swapped back to the other coil. It was pretty scraped up and had a lot of exposed metal on it...Hard to say. But I plan on getting this beast wrapped up today. I still can't believe how torquey and quick these bikes are!

Jetting is solid with the pod filters. Electrodes are a nice milky brown and no pop on decell. Need to adjust the clutch a bit still but we are up and running with full LED lighting and kick only. I'll be sure to report back my findings.

Cheers!

1204_cb77
honda305.com Member
Posts: 27
Joined: Wed Mar 06, 2019 1:55 pm

Post by 1204_cb77 » Wed May 01, 2019 9:16 pm

Well hot damn my friends. The 305 is kicking! I need to get my jetting in order a bit more but it is running pretty damn good!

Thank you LM for the final help to my electrical woes. I guess this technically shouldn't be part of this thread as I AM running a battery but hey, maybe it'll help another member! I still need to get my mufflers in order as you can see but runs ok without, must kind of loud! I probably rode 50 miles today alone testing and tuning and decided enough is enough. It is a 50 year old motorcycle. I keep trying to compare this to my Kawasaki Z1000!

Anyways, here are some beauty shots :) Talk soon! I couldn't thank you all enough for your time and help on getting this awesome machine back on the road!

Max
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