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 10-22-2013, 07:01 PM   #16
bikecat
Beastly Adventurer
 
bikecat's Avatar
 
Joined: Jan 2006
Location: Tropical Far East
Oddometer: 1,069
When my airhead failed to get pass 5K rpm, it was because of a broken ring in one of the cylinders.

I belong to the "no irregardless" camp. The "ir" is redundant.
bikecat is offline   Reply With Quote
Old 10-22-2013, 07:06 PM   #17
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,539
Quote:
Originally Posted by batoutoflahonda View Post
Within the past week or so,...
Rather a large clue right there.

Do gas stations in your area change to winter formula gas right about now?
Plaka is offline   Reply With Quote
Old 10-22-2013, 07:16 PM   #18
Airhead Wrangler
Adios Mexico
 
Airhead Wrangler's Avatar
 
Joined: Mar 2008
Location: Back in Seattle, FINALLY
Oddometer: 6,274
I'd CAREfully check the diaphragms. Sometimes you need to gently stretch them a bit and hold them up to the light to see smaller tears in them. It doesn't take much of a hole to make a big drop in power.
__________________
R80ST Gets The HPN Treatment
Seattle to TDF on an airhead

Current rides: HPN #834, '93 R100GSPD "red rocket", '73 R75/5 Toaster mongrel, '80 Ducati Pantah 500SL, '92 DR350, '67 Honda SS50, '80 Honda Chaly.
Airhead Wrangler is offline   Reply With Quote
Old 10-22-2013, 07:21 PM   #19
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,539
Quote:
Originally Posted by Airhead Wrangler View Post
I'd CAREfully check the diaphragms. Sometimes you need to gently stretch them a bit and hold them up to the light to see smaller tears in them. It doesn't take much of a hole to make a big drop in power.
it also takes little stretching and poking to turn a perfectly good diaphragm into junk. At which point you get to replace it, think you found the problem and find out you haven't.

If it is running lean at high RPM due to a diaphragm problem, it won't be on both sides. So a look at the plugs or quickly check head temps with a cheap IR thermometer to reveal the condition. Then you go looking for a cause. If you find no evidence of it running lean, go looking for something else.

OP stated plugs were normal. But he didn't state if he did a high speed chop when the power was down.
Plaka is offline   Reply With Quote
Old 10-22-2013, 07:22 PM   #20
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 7,966
Quote:
Originally Posted by Airhead Wrangler View Post
I'd CAREfully check the diaphragms. Sometimes you need to gently stretch them a bit and hold them up to the light to see smaller tears in them. It doesn't take much of a hole to make a big drop in power.
No AW. I think it's winter mix gasoline. Slightly lowering gasoline's boil point always slows my bike down at least 20mph.
supershaft is online now   Reply With Quote
Old 10-23-2013, 12:51 AM   #21
batoutoflahonda OP
Beastly Adventurer
 
Joined: Aug 2007
Location: Easton Wa
Oddometer: 1,354
A friend suggested winter gas. I dismissed it as witchcraft. Then I pondered some octane boost. Then I thought about getting a shaman and some herbs. So I settled on Seafoam as I thought maybe there was water in the gas. Seemed to cover all my bases, according to the lable. I needed spark plugs any way.

So checked the timing and all is good. It does hit the throttle stops and I have tried shifting into lower gears, but still can't get it to red line on the pass. Climbing the Snoqualmie pass, if I down shift it struggles to get back up to the speed it lost on the down shift. In a flat run I can get 7k rpm in the first three gears. 4th and 5th it won't get much over 6k @ 94 mph, fastest I could get it today. The point gap is good. I wondered about the dyna and the condenser, left it hooked up so I could switch on the road if need be.

I stuck new diaphragms in the other night, before this post. Didn't see any holes in the old ones, but wondered if they might be weak. It actually helped with the response a bit. I do notice just a very slight hesitation rolling on at part throttle. The new diaphragms actually helped with that, as it was noticeable before. Now I can feel it, but ever so slightly.

Thinking I'm going to get a new set of points and condenser on order. Check the coil. One thing I have also been pondering, is the Y collector for the exhaust rattles when I start it. This started a while ago. If I kick it, it stops rattling. Thought it was kinda amusing, but wondering if a baffle hasn't come loose and is plugging it a bit. Sucks, because all the new ones are shiny. It will just totally clash with the patina of the bike. Suppose I should bite the bullet and check compression. Would be a total bummer if it went south after two years and maybe 20k miles.

Thanks for the replies so far. And the English lesson. This bike is so cool in that runs no matter what, and through this whole thing the past few days, every thing I tweak here and there helps it run better. Probably the best I've ever tuned it. That's what has me so perplexed. Even when it's acting up, it's fun to try diagnose. It's an amazing piece of machinery.
__________________
It's eight and a half gallons of gas; and an engine. What more do you need?-- BMW R80G/S

Save lives. Legalize lane sharing.

Cow eyes don't glow.

batoutoflahonda screwed with this post 10-23-2013 at 01:17 AM
batoutoflahonda is offline   Reply With Quote
Old 10-23-2013, 01:24 AM   #22
SprintSix
Gnarly Adventurer
 
Joined: Dec 2009
Location: Ohio
Oddometer: 151
Main jet too rich? The weather is gettin colder. The term pass makes me think high elevation. Winter gas.

Add to the above your bike should have no problem breaking 100mph.

Kinda surprised supershaft didnt offer this first.
SprintSix is offline   Reply With Quote
Old 10-23-2013, 04:31 AM   #23
Stan_R80/7
Beastly Gnarly
 
Stan_R80/7's Avatar
 
Joined: May 2012
Location: VA
Oddometer: 986
Sounds like it's time to check the engine compression. My low compression R80/7 shows 150 psi on each cylinder. Good luck!
Stan_R80/7 is offline   Reply With Quote
Old 10-23-2013, 06:40 AM   #24
JonnyCash
turd polisher
 
Joined: Jan 2011
Location: Midcoast, Maine
Oddometer: 1,346
Quote:
Originally Posted by SprintSix View Post
Main jet too rich? The weather is gettin colder. The term pass makes me think high elevation. Winter gas.

Add to the above your bike should have no problem breaking 100mph.

Kinda surprised supershaft didnt offer this first.
Cold weather would ask that you richen the mixture actually. Air is denser at lower temps, more oxygen in the intake means you want more fuel.
__________________
I wouldn't bring her home to Mama, but Mama ain't home tonight.
JonnyCash is offline   Reply With Quote
Old 10-23-2013, 06:41 AM   #25
Uncle Pollo
happy cachiporra
 
Uncle Pollo's Avatar
 
Joined: Jun 2006
Location: Albuquerque, Neue Messico
Oddometer: 47,086
Quote:
Originally Posted by ME 109 View Post
Well I did start typing 'reach down with your left hand and'...................but then I also thought about batoutoflahonda not leaving enough parts for us.

As it is pulling redline in third, I would first suspect yo butterflies not fully opening.
this
Uncle Pollo 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 09:51 AM.


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