ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-29-2013, 09:01 PM   #16
band-aid OP
Adventurer
 
Joined: Sep 2011
Location: Brooklyn, NYC
Oddometer: 24
Pommie John- Thanks, we are on new plugs already- I'm going to check the timing on Saturday and assess the points. I don't know the history of the bike or when the points were last inspected/set or let alone replaced. I thought we'd tackle the obvious first but it's time to dig deeper for sure. I'm hoping the timing is off and I don't have a gremlin in the carburetors.

Supershaft- I have very little experience with K+N filters though I do understand they are meant to be oiled. I was alarmed when it was sopping wet and black but now that I think about it, it very likely was just the K+N filter oil showing all of the dirt sucked in and subsequently it was black. Either way, it seemed like a condition that could create difficulty with air intake due to the sheer density of muck and black grime so that filter was replaced and we're starting from scratch with a Mahle filter.

And yes, to all who suggested it- there is always the possibility that this bike has 135k and not 35k- Even if it's not 135k, these may not be the original instruments. Who knows- I've seen bikes with confirmed 80k on the clock with less wear than other bikes that show 25k. Parking outside for 30 years makes a difference in the rust department at least (as with my friend's 84' R80 where every bolt breaks on the way out) with half the miles of my 74' R60 with nearly triple the mileage...

Anyway, I will pick up my investigation with timing and points this weekend and see where that takes me. Updates to come.

Thanks!
band-aid is offline   Reply With Quote
Old 04-29-2013, 09:45 PM   #17
pommie john
Beastly Adventurer
 
pommie john's Avatar
 
Joined: Apr 2008
Location: Brisvegas, Australia
Oddometer: 1,375
One other thing, once a plug has been carbon fouled, it's very difficult to get it to run well again, no matter how well you clean it. Don't ask me why, it's just what seem to happen when I try it.
__________________
The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.
Bertrand Russell
pommie john is offline   Reply With Quote
Old 04-30-2013, 12:13 PM   #18
Foot dragger
singletracker
 
Foot dragger's Avatar
 
Joined: Dec 2006
Location: chico,just below rag dump(nor-cal)
Oddometer: 12,782
Quote:
Originally Posted by Plaka View Post
The float bowls have vents and overflow tubes. if these are plugged the carbs won't feed any gas when running. Conceivable if they are clogged AND the floats stick down the gas could go through the jets into the intake AND if the intake valve is open it could go from there into the cylinder at which point a certain amount could get past the rings into the bottom end. It's volatile and burns off quickly but washing the oil off the cylinder walls isn't good.

Getting "gallons" of gas into the bottom end sounds very odd indeed. I don't necessarily mean "odd" in a nice way but I'm not a nice person, ask anyone.

You turn the petcocks off to keep gas from going on the exhaust and ground if the float sticks when parked. Even then it can stick while riding and piss on your boot.

If you don't like it, sell the airhead and get a Honda or something.
The bike would start blowing much smoke out the pipe when the oil was full of gas,it happened a few times.
The guy who traded me a modern bike for the airhead had it do the same thing.
He thought something was seriously wrong with the smoke and all,I told him to dump the oil and keep the petcock turned off when not in use.
----------------------------------------------------------------------

I think you may be a great candidate for a Honda,maybe an NC700X or some other porpoise looking device.
No re-engineering,no rebuilding of ancient german devices,what would you do with your time?
__________________
Some bikes around at times
Foot dragger is offline   Reply With Quote
Old 05-01-2013, 04:01 AM   #19
regomodo
Gnarly Adventurer
 
Joined: Jul 2012
Location: Bristol, UK
Oddometer: 185
Quote:
Originally Posted by pommie john View Post
Band Aid, rule number one when setting up the carbs, is check the ignition is right first.

New plugs, ( you've probably done that if they keep fouling), new points, set the timing, then play with the carbs. It's meaningless to chase a carburation problem if the ignition is not burning the fuel properly.
I thought valve clearances were 1st?
__________________
79 BMW R45 Cafe
82 Suzuki DR125
02 Suzuki RM 250
regomodo is offline   Reply With Quote
Old 05-01-2013, 05:28 AM   #20
pommie john
Beastly Adventurer
 
pommie john's Avatar
 
Joined: Apr 2008
Location: Brisvegas, Australia
Oddometer: 1,375
Quote:
Originally Posted by regomodo View Post
I thought valve clearances were 1st?
Not a bad idea to do them too, but my point was, don't go straight into the carbs just 'cos it's running bad.
__________________
The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.
Bertrand Russell
pommie john is offline   Reply With Quote
Old 05-01-2013, 10:28 AM   #21
190e
Gnarly Adventurer
 
Joined: Feb 2013
Oddometer: 460
Quote:
Originally Posted by regomodo View Post
I thought valve clearances were 1st?

If the carbs are being tuned valve clearances should always be done first with good reason.

Changes of a couple of thou can have a noticeable effect on idle speed, mixture and carb balance. Widening the clearances makes the valve timing slightly milder with less overlap which increases torque and efficiency at idle so idle speed goes up. Although you haven't adjusted the carbs the engine is now effectively seeing a slightly richer mixture.



Conversely closing up clearances reduces torque and efficiency so idle speed will usually drop.
190e is offline   Reply With Quote
Old 05-02-2013, 06:45 AM   #22
Bill Harris
Confirmed Curmudgeon
 
Bill Harris's Avatar
 
Joined: Sep 2008
Location: backwoods Alabama
Oddometer: 6,750
On setting up/adjusting carbs, make sure that everything is "shipshape and Bristol fashion". New points-- gapped and timed, valves adjusted, new plugs, etc. Eliminate as many variables as possible. "Fouling plugs and not running well" usually suggests to me that it's running rich and is typically related to carb maintenance, such as float/fuel level.

My 2c.

--Bill
__________________
'73 R60/5 Toaster
Luddite. Not just a philosophy, a way of life...
Bill Harris is offline   Reply With Quote
Old 05-02-2013, 10:50 AM   #23
band-aid OP
Adventurer
 
Joined: Sep 2011
Location: Brooklyn, NYC
Oddometer: 24
Some progress

Had a chance to get in to the timing case one evening this week and found the points gap set incorrectly and the timing retarded quite a bit. Adjusted both and the bike idles better and ran without the same bogging problem as before. It was a very short ride however and further riding will be needed to confirm that it is resolved. I found that the dynamic timing was on point at max advance and the idle slightly below the mark after tuning- I don't think I need to fixate on this if it idles okay- right? Also will likely clean and lube the advance unit and swap the springs (only cause I have some collecting dust) I intend to resync the carbs this weekend using the spark short method and (thanks all for the reminder) I will check and set the valves before getting into any of it.

It seems like a number of things have been partial contributors and that basically what's needed is just a complete tuneup. You're all correct to point out that the carbs were done out of sequence but with them just hanging out there in the open sometimes it's tempting to tackle them first...
band-aid is offline   Reply With Quote
Old 05-02-2013, 04:36 PM   #24
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,456
This scenario is very common for all internal combustion machines. The rider thinks Carburetor first but the answer is otherwise 99% of the time. Usually it's ignition but on the Airheads we have added valves before that because it's just the way they are.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 05-02-2013, 09:04 PM   #25
Andosan
Adventurer
 
Joined: Apr 2012
Location: Brooklyn
Oddometer: 65
Quote:
Originally Posted by band-aid View Post
Pommie John- Thanks, we are on new plugs already- I'm going to check the timing on Saturday and assess the points. I don't know the history of the bike or when the points were last inspected/set or let alone replaced. I thought we'd tackle the obvious first but it's time to dig deeper for sure. I'm hoping the timing is off and I don't have a gremlin in the carburetors.

Supershaft- I have very little experience with K+N filters though I do understand they are meant to be oiled. I was alarmed when it was sopping wet and black but now that I think about it, it very likely was just the K+N filter oil showing all of the dirt sucked in and subsequently it was black. Either way, it seemed like a condition that could create difficulty with air intake due to the sheer density of muck and black grime so that filter was replaced and we're starting from scratch with a Mahle filter.

And yes, to all who suggested it- there is always the possibility that this bike has 135k and not 35k- Even if it's not 135k, these may not be the original instruments. Who knows- I've seen bikes with confirmed 80k on the clock with less wear than other bikes that show 25k. Parking outside for 30 years makes a difference in the rust department at least (as with my friend's 84' R80 where every bolt breaks on the way out) with half the miles of my 74' R60 with nearly triple the mileage...

Anyway, I will pick up my investigation with timing and points this weekend and see where that takes me. Updates to come.

Thanks!
An R80 with broken bolts????
Andosan is offline   Reply With Quote
Old 05-03-2013, 05:31 AM   #26
bpeckm
Grin!
 
bpeckm's Avatar
 
Joined: Apr 2008
Location: Road Island
Oddometer: 5,687
Are you still getting oil from the breather? There is a newer breather valve that is a drop-in replacement, and helps with blow-by, if indeed that was the initial problem....

__________________
XS650 becomes a VT BackRoadRunner
Loving the 80ST
I love projects that take twice as much effort as should be needed. Should be an Airhead motto. (disston)
__________________
bpeckm is offline   Reply With Quote
Old 05-03-2013, 09:23 AM   #27
band-aid OP
Adventurer
 
Joined: Sep 2011
Location: Brooklyn, NYC
Oddometer: 24
Quote:
Originally Posted by bpeckm View Post
Are you still getting oil from the breather? There is a newer breather valve that is a drop-in replacement, and helps with blow-by, if indeed that was the initial problem....

That is indeed a problem on my OTHER R60/6. This post has been about a friend's bike that I've been working on. I am considering the Reed Valve swap but I'm also considering just renewing the old style breather- I understand there are some crafty airheads manufacturing the old style discs out of PCB material?

Honestly, I just have to open it up and check the condition- haven't made it there yet but it's on my lengthy To Do list.

Do you happen to know if I need to swap the housing and hose to use the new breather valve or will it fit under existing? I ask because the reed valve is about $45 or so on MAX but when you add the housing you're suddenly in for $150 all told...
band-aid is offline   Reply With Quote
Old 05-03-2013, 09:59 AM   #28
190e
Gnarly Adventurer
 
Joined: Feb 2013
Oddometer: 460
You don't need to renew the housing to fit the reed breather.

If you want to try a mod on the original or replacement paxolin disc, drill a 1 mm hole approx. half way out from the centre. I believe this was a BMW instigated mod before the reed breather came along. Might be worth a try as it's free.
190e is offline   Reply With Quote
Old 05-05-2013, 08:14 PM   #29
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,456
Repairing the original style breather valves is a DIY project. You make a disk from some kind of plastic stuff. Is it PCB circuit board material? I don't know I replaced with the reed valve which is a direct replacement. The problem is getting the old style breather out. It is hard to get to and it is really stuck in there.

You can fashion a puller of sorts maybe. There is a puller sold by one of the after market tool guys. I think I was lucky to get mine out by prying with a screwdriver or something. This doesn't work for everybody. Careful not to cause any damage to the block getting the thing out.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 05-05-2013, 11:26 PM   #30
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,581
Quote:
Originally Posted by disston View Post
Repairing the original style breather valves is a DIY project. You make a disk from some kind of plastic stuff. Is it PCB circuit board material? I don't know I replaced with the reed valve which is a direct replacement. The problem is getting the old style breather out. It is hard to get to and it is really stuck in there.

You can fashion a puller of sorts maybe. There is a puller sold by one of the after market tool guys. I think I was lucky to get mine out by prying with a screwdriver or something. This doesn't work for everybody. Careful not to cause any damage to the block getting the thing out.
PCB material is glass reinforced phenolic or in some cases, epoxy. yeah, it works good. You can get totally blank boards from an electronic supply. (it has a layer of copper in it. So what?). But the valve doesn't work any better compared to the new style.
Plaka is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 08:24 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014