honda305 Home honda305 Auctions honda305 Gallery honda305 Forum


honda305.com Forum

Login
□ Search
□ FAQ 
□ 
Vintage Honda Owners,
Restorers, Riders and
Admirers

Timing Advance sticking

Points Based Ignition | Electronic Ignition Upgrade
Raceman
honda305.com Member
Posts: 35
Joined: Sat Jun 02, 2012 1:02 pm
Location: Tennessee

Timing Advance sticking

Post by Raceman » Sun Jan 25, 2015 11:12 am

I recently brought a dormant 305 Dream back to life. It runs good except rpm's do not return to idle quickly. I thought initially that the slide was sticking, but that is not the case. The timing advance is sticking as confirmed by a timing light. After 6-8 seconds it retards and speed decreases. I am hoping since the advance unit lives in a lubricated environment, it may improve after riding it for a while. The springs may be weak. I can move the points cam and it returns, bit does not snap back. I assume in order to service the advance unit, I will have to drop the engine to remove the head plate. Is that correct? You thoughts and ideas appreciated.

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

Re: Timing Advance sticking

Post by LOUD MOUSE » Sun Jan 25, 2015 11:44 am

You are pretty much correct on everything.
Fortunately the springs can be replaced once the top cover is off.
I have springs here.
They are different form the CB/CL type. ..... ....lm
Raceman wrote:I recently brought a dormant 305 Dream back to life. It runs good except rpm's do not return to idle quickly. I thought initially that the slide was sticking, but that is not the case. The timing advance is sticking as confirmed by a timing light. After 6-8 seconds it retards and speed decreases. I am hoping since the advance unit lives in a lubricated environment, it may improve after riding it for a while. The springs may be weak. I can move the points cam and it returns, bit does not snap back. I assume in order to service the advance unit, I will have to drop the engine to remove the head plate. Is that correct? You thoughts and ideas appreciated.

Raceman
honda305.com Member
Posts: 35
Joined: Sat Jun 02, 2012 1:02 pm
Location: Tennessee

Timing Advance sticking

Post by Raceman » Sun Jan 25, 2015 12:39 pm

Thanks for the prompt reply. I'll ride it a little to see if anything changes. If not , I'll PM you to arrange buying a set of springs. This bike is the newest member of the Critter crew. It's known as the Polecat. I think you know these guys. Fun bunch.

Raceman

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

Re: Timing Advance sticking

Post by LOUD MOUSE » Sun Jan 25, 2015 2:51 pm

As you tell use the points cam is slow to return.
YOUR SPRINGS ARE SHOT.
Time won't fix that unless you are magic. .............lm

Raceman wrote:Thanks for the prompt reply. I'll ride it a little to see if anything changes. If not , I'll PM you to arrange buying a set of springs. This bike is the newest member of the Critter crew. It's known as the Polecat. I think you know these guys. Fun bunch.

Raceman

User avatar
Hamamatsu Nippon
honda305.com Member
Posts: 111
Joined: Sat Nov 12, 2011 6:37 pm
Location: SW Ontario, Canada

Post by Hamamatsu Nippon » Mon Jan 26, 2015 2:19 pm

Hmmm, that's interesting. I have the same slow to return idle. The slide, cable, and throttle assy. are good. My points cam snaps back pretty good though. Can you change the springs from the top cover or does the cam sprocket have to come out?
1967 CA78
1965 CM90

The value of life can be measured by how many times your soul has been deeply stirred.
Soichiro Honda

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

Post by LOUD MOUSE » Mon Jan 26, 2015 3:20 pm

Pack the head area under the cam sprocket and carefully remove and replace the springs.
Be careful not to stretch the new springs. .......lm

Hamamatsu Nippon wrote:Hmmm, that's interesting. I have the same slow to return idle. The slide, cable, and throttle assy. are good. My points cam snaps back pretty good though. Can you change the springs from the top cover or does the cam sprocket have to come out?

cknight
honda305.com Member
Posts: 427
Joined: Wed Apr 05, 2006 3:55 pm
Location: Daytona Beach, FL

Post by cknight » Mon Jan 26, 2015 4:42 pm

To make sure the points weights are really returning to their stops at idle, check by using a timing light, confirming your original static setting. If you don't have a timing light, press on the end of the points cam (with the cover removed) with the engine running, to exert some drag. If the idle drops right down to spec, that should confirm the unhappy springs. Be aware that some of the replacement CB advancer springs being sold are actually CA style springs, and will not work properly. Regards, Chase

Post Reply
cron




 

CB-77 | CYP-77 | Road Test | Riding Log | Literature | Zen | Marketplace | VJ Survey | Links | Home