Best option to rebuild PD50Bs

If it's broken or just needs tweaked

Moderators: Volker_P, tidd650

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Mon Jun 25, 2012 6:08 am

Certainly something you will hear against say 20000 miles.

However this corresponds to a general metallic noise level, not peculiarly valve or chain noise. If you can hear chain or valve noise out of this increased level, this is probably something that may be reduced.

Verify cam chain tension at different positions. If turns from tight to loose during turning the engine, better replace it. This is a good idea at 47k anyway.
I replaced mine at about 45k, the engine ran up to 60k until I used a spare one due to the oil consumption.

A torn cam chains typically will end up in a few bend valves.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

Totaled108
Posts: 65
Joined: Mon Oct 03, 2011 3:45 am

Re: Best option to rebuild PD50Bs

Postby Totaled108 » Tue Jun 26, 2012 3:49 am

I have never heard of a torn cam chain. Scary!!

Started her up yesterday morning and it was still LOUD with that clattering noise, so only let it run for a minute or so. Then went about re tightening the timing chain while turning the crank as I tightened the tensioner. All that noise is gone and I rode over 25 miles to work, the store and home. Success, in that realm anyways.

#4 carb has a very minor leak at the outer edge of where the float bowl meets the carb body, but no fuel is dripping from the overflow tube. I did reuse the float bowl gaskets, kind of dry when they went in. :( I'm thinking maybe smooth out the plunger seat while replacing the bowl gasket first.

Other then that, there is a slight hesitation at very low RPMs, as in just off idle when in gear. It revs just fine with the clutch in, and pulls very well after that initial hesitation. The accelerator pump is old, but looked to be in good shape when I put it in a few days ago. I also did all the adjustments for it per the manual on cosky's site (awesome site!!!).

The fun thing is, I have ANOTHER 1980 CB650, but it's not a Custom. In the next few weeks I will be tearing down the carbs and getting those O-ring #'s. Having 2 CB650's to play with never hurt. ;)

Sad thing is I am starting school in a week so I need to leave one in good running order so I can have reliable transport to work 2 days a week, or so. The other days I'll ride my bicycle. :)

Thank you so much for the help Volker!!!

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Tue Jun 26, 2012 6:32 am

You're welcome!

Whenever I need really reliable transport I take my old bicycle. :lol:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

Totaled108
Posts: 65
Joined: Mon Oct 03, 2011 3:45 am

Re: Best option to rebuild PD50Bs

Postby Totaled108 » Tue Jun 26, 2012 12:57 pm

8) The bicycle is almost 10 years older then the CB650, and I have put about 8,000 miles on it the last ~4 years. :lol:

Whats funnier is, I have a Class A drivers license, I driver commercial tractor trailers for a living. I love to drive, I just like riding my bike more! :)

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Wed Jun 27, 2012 1:29 am

Here you are my present most reliable transport:
Attachments
bicy_25p.jpg
bicy_25p.jpg (73.83 KiB) Viewed 9322 times
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

Totaled108
Posts: 65
Joined: Mon Oct 03, 2011 3:45 am

Re: Best option to rebuild PD50Bs

Postby Totaled108 » Wed Jun 27, 2012 11:26 am

Nice ride! Simple effective bike, coaster brake, and nice generator set up, nice frame pump. Where have I seen this great bike before...

Fred Birchmore rode a very similar set up around the world in 1934-1935. 8)
Enjoy!! :D
Attachments
clr050.jpg
Fred Birchmore
clr050.jpg (153.02 KiB) Viewed 9318 times

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Thu Jun 28, 2012 1:19 am

Impressing.
The swiss army has similar bikes, too. There are still several races with them. The original old swiss army bikes are really expensive now.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

Totaled108
Posts: 65
Joined: Mon Oct 03, 2011 3:45 am

Re: Best option to rebuild PD50Bs

Postby Totaled108 » Thu Jul 12, 2012 8:54 pm

I turned the idle air adjusting needles out about 2/3 over the ~2 1/8 that were set from the bench setting. Now there is no hesitation what so ever throughout the throttle range. I'm very happy with the old girl. :)

Just hoping it's not just masking a different problem. :?

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Fri Jul 13, 2012 12:56 am

The impact of the idle adjust screws on the carb behaviour is low and only affects idle and very low rpm. So no chance to mask really serious problems there.
Altitude and air filter may explain deviations. So if not done, check out your airbox but don't worry further if everything there looks all right. :wink:

Sometimes even a CB650 just runs fine! :lol:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

Totaled108
Posts: 65
Joined: Mon Oct 03, 2011 3:45 am

Re: Best option to rebuild PD50Bs

Postby Totaled108 » Tue Jul 17, 2012 11:27 pm

Yeah, the hesitation seems to be there some days and not there at all others. Oh well.

I'm at sea level and up to 500ft, though the air box does have an odd bend at that main connection between the front section and main filter housing. Looks like someone over tightened it and the ovel 'female' end seems to not hold outward pressure when tightening down the big clamp even a little. It probably is letting a bit more air through bypassing the filter itself. :oops: It just now popped into my head that it did seem wierd as I installed the carb the last time.

Might that cause a hesitation like I have? I'm guessing so...

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Wed Jul 18, 2012 1:27 am

Sure, air leaks may cause hesitations, especially when you are already close to lean (and stock CB650 settings usually is close to lean).
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

MiGhost
Posts: 379
Joined: Tue Jun 07, 2011 2:30 am
Location: South Central Mitten

Re: Best option to rebuild PD50Bs

Postby MiGhost » Tue Jul 30, 2013 3:02 pm

Volker_P wrote:
cb650 wrote:Volker I would suggest a locked thread with this info and the electric interchange list.

It's already in my internal technical links list.
One may also click on "forum links" in my signature to get there. :wink:
I may still compose something anyway.


Updated my post to include the original carb specs. :D

Volker. Feel free to copy over to a FAQ if you feel it is needed.
Will update the PD50D specs as soon as I can get my hands on a set!

Ghost
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper

User avatar
Volker_P
Posts: 5508
Joined: Mon Mar 06, 2006 1:53 am
Location: southern Germany

Re: Best option to rebuild PD50Bs

Postby Volker_P » Wed Jul 31, 2013 1:50 am

Thanks!
Feel free to make a FAQ! :lol:

I do not intend going beyond taking care for my "internal technical links" list. :wink:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

Pbiggs
Posts: 146
Joined: Fri Aug 09, 2013 6:44 pm
Location: Salt Lake

Re: Best option to rebuild PD50Bs

Postby Pbiggs » Thu Jan 30, 2014 7:04 pm

Ghost isn't messin around :lol: I have a few parts I might end up letting go for a good cause

MiGhost
Posts: 379
Joined: Tue Jun 07, 2011 2:30 am
Location: South Central Mitten

Re: Best option to rebuild PD50Bs

Postby MiGhost » Mon Feb 03, 2014 11:55 am

I am always looking for PD50C, PD50D, and PD50E racks to get the needed information from. :)
~ Ghost

PD50 Carb Info
82 CB650SC Brake Caliper Info

Stable
Wayward Son:1980 CB650C, RestoMod Period Custom Touring
Bad Moon: 1983 XJ750MK Midnight Maxim, Full Dress Tour Deluxe w/ X-1 Fairing
Nemesis: 1983 XJ750K Maxim, Old School style chopper


Return to “Technical Discussion”

Who is online

Users browsing this forum: Google [Bot] and 51 guests