Search found 27 matches

by Rocket Man
Mon Sep 01, 2014 11:11 pm
Forum: Technical Discussion
Topic: 1980 CB650C Restoration Overview
Replies: 1
Views: 1820

1980 CB650C Restoration Overview

7000 miles and a few problems later, I am on the road with a s**t eatin grin :D . After clearing up the coil and spark plug lead age issues, I went all out to eliminate the carburetor air valve problems (super small and inaccessible holes). JB weld does the trick. Carb threads: http://www.hondacb650...
by Rocket Man
Mon Aug 25, 2014 10:03 pm
Forum: Technical Discussion
Topic: Timing Chain Tensioner
Replies: 3
Views: 2432

Re: Timing Chain Tensioner

It was in the wrong spot, visible from below. It's worth cleaning out the pan anyway.
by Rocket Man
Sun Aug 17, 2014 2:39 pm
Forum: Technical Discussion
Topic: Timing Chain Tensioner
Replies: 3
Views: 2432

Timing Chain Tensioner

I am putting a 1980 cb650c back together and could not get the barrels on the pistons with the tensioner in the barrels. So I inserted it after the barrels were almost seated and have a question. The tensioner appears to be in the right spot and the crank spins freely, but it is under tension. Pushi...
by Rocket Man
Tue Dec 17, 2013 11:53 pm
Forum: Technical Discussion
Topic: Holy Smoke
Replies: 4
Views: 2637

Re: Holy Smoke

How many miles since it runs again? Did it ever get really warm during a longer, extended ride since then? I have put a few hundred miles on it since it was mothballed for 10 years or so. I have not taken it on a really long ride, 30 miles or so. If due to rings and if you already see something at i...
by Rocket Man
Sat Nov 30, 2013 6:24 pm
Forum: Technical Discussion
Topic: Holy Smoke
Replies: 4
Views: 2637

Holy Smoke

My 650 has just over 7000 miles on it and after being resurrected I have still another issue. I may be loosening up the rings with Marvel Mystery Oil, but do get white/blueish smoke at idle from some cylinders. My compression is at 80 psi in all cylinders, which sounds low. The stem seals should not...
by Rocket Man
Sun Nov 24, 2013 11:01 pm
Forum: Technical Discussion
Topic: Acceleration issue
Replies: 15
Views: 9534

Re: Acceleration issue

So I did something similar anyway and got lucky. My diaphragms must be good in the air cut-off valves. Most likely a plugged hole, but it runs great now!! :D :D :D :D
by Rocket Man
Sun Nov 24, 2013 1:07 pm
Forum: Technical Discussion
Topic: Resurrected?
Replies: 23
Views: 13075

Re: Resurrected?

Eureka! The toothpick idea has worked for my issue. I used screws and ultra blue permatex and this chilly morning it ran way way better. A JOY
by Rocket Man
Tue Nov 19, 2013 8:57 pm
Forum: Technical Discussion
Topic: Resurrected?
Replies: 23
Views: 13075

Re: Resurrected?

I am in the process of addressing the air cut-off valves to eliminate that as a suspect. I did a static sync on the cards awhile back. The new coil was for #1 & #4, and may not have grounded to the bike frame. Not sure if that could do it. I'll check the resistance on the pick-up/pulsar both col...
by Rocket Man
Fri Nov 15, 2013 7:02 pm
Forum: Technical Discussion
Topic: Resurrected?
Replies: 23
Views: 13075

Re: Resurrected?

So the new coil provided some needed stability, yet while warmed up and choke off the acceleration issue persists. I reliably get all four cylinders kicking in when twisting the throttle, but at lower throttle and from a stop it bogs a bit still. -Could it be an idle mixture port fowled or? -Still p...
by Rocket Man
Thu Nov 07, 2013 12:53 am
Forum: Technical Discussion
Topic: Resurrected?
Replies: 23
Views: 13075

Re: Resurrected?

Just purchased one so we shall see. I always thought a coil either worked or it didn't. But it makes some sense that a crack in the plastic could affect the temperature/resistance relationship... or something
by Rocket Man
Wed Nov 06, 2013 1:21 pm
Forum: Technical Discussion
Topic: Resurrected?
Replies: 23
Views: 13075

Re: Resurrected?

Sure do, and I am hesitant to pull the carbs off the rack to access all of them. Might not have all the tools needed, especially a sonic cleaner.
by Rocket Man
Sun Nov 03, 2013 5:27 pm
Forum: Technical Discussion
Topic: Resurrected?
Replies: 23
Views: 13075

Re: Resurrected?

Here are the plugs and it looks like #2 may have a bit of an issue. I did notice some smoke come out of an exhaust after riding it for awhile. It ran fine cold, but once warmed up it has trouble off the line and at steady speed it breaks up a bit. Accelerates hard enough, but all in all a bit hard o...
by Rocket Man
Sat Oct 26, 2013 11:45 am
Forum: Technical Discussion
Topic: Acceleration issue
Replies: 15
Views: 9534

Re: Acceleration issue

These carbs are not the CV type. 1980 cb650c with 7000 miles on it. I like the idea of jamming a toothpick in the carb port to the air cut off valve, especially if I don't have to remove the carbs. I still suspect a spark issue from #4 coil, so I still have some testing to do. Not to mention a plug ...
by Rocket Man
Sat Oct 26, 2013 12:11 am
Forum: Technical Discussion
Topic: Air cutoff help...
Replies: 17
Views: 10555

Re: Air cutoff help...

How are those tooth picks holding up?
by Rocket Man
Thu Oct 24, 2013 10:35 pm
Forum: Technical Discussion
Topic: Acceleration issue
Replies: 15
Views: 9534

Re: Acceleration issue

I have heard that the diaphragms are not really needed and a port can be plugged to avoid problems.

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