The Sportster and Buell Motorcycle Forum Biltwell  

Go Back   The Sportster and Buell Motorcycle Forum > SPORTSTER MOTORCYCLE ZONE > Sportster Motorcycle Era Specific and Model Specific > Ironhead Sportster Motorcycle Talk (1957-1985)
XLF Gallery XLF Classifieds XLF Blogs XLF Shout XLF Arcade XLF Disclaimer/Privacy Statement/Terms Of Use

Ironhead Sportster Motorcycle Talk (1957-1985) For all those that wanna talk about Ironhead Sportster Motorcycles

Members Birthdays
DaddyJay, sixshooter (67), cartoad2001 (65), Dirty Ernie (59), bri1200c (51), pquirk (48), GOTWA (45), gremlinsteve (45), lbowles2 (43), Guess (35), rnaway22es, landon283 (26)
883 Sportster
Lickscycles
DK Customs
Foxcreek Leather

RYCA Motors
Reply
 
Share Thread Tools Display Modes
  #21  
Old 6th August 2013
DDDDylan DDDDylan is offline
Harley Engineer
 
Join Date: Nov 2012
Posts: 322
Sportster/Buell Model: XLS 1000
Sportster/Buell Year: 1979
Other Motorcycle Model: CB750
Other Motorcycle Year: 1995
Reputation: 7365
DDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really niceDDDDylan is just really nice
Default

Quote:
Originally Posted by carbineken View Post
Put the light on it last night, it was a little off. Its as dead on as I can get it now. Went for a short ride with no issues but this morning it did it again. Most of my riding is on the highway to and from work......45 miles one way and mostly 65-75 mph. My idle is set at roughly 1100-1200 and I don't sit around at idle very much. I'm sure there is already some carbon built up in there but I installed new pistons/cylinders in April. They were spotless then. 91 octane is the highest I can get at the pumps here and I run 91 non-ethanol 95% of the time. Every now and then I get some ethanol in there....sometimes the 2.2 gallon tank decides where I get fuel.
Is this dieseling causing any harm to my engine? Right now it just annoys me. I'm going to pick up some Blue Streak points/condensor and install those. This started after going back to points so.....
Otherwise bike runs without complaint. Starts in 1 or 2 kicks everytime...hot or cold. Pulls hard from idle to 5500 with no hesitation or flat spots.
As stated above, if the bike starts and runs well, the timing is good. The problem is that it is dieseling after you kill the ignition, so ignition parts and ignition timing should have nothing to do with the dieseling.

Post pictures of your plugs. There are experts on here at reading plugs.

Do what ever you have to do to get some high octane fuel and run that to see what that does. It won't "fix" carbon buildup if that is your problem, but it will make the dieseling symptom stop. If deposits are your problem, the cleaning methods above can clean them out. Your deposit root cause is either running too rich, running too cool, or burning too much oil.
__________________
1979 XLS, '76 Keihin butterfly carb, Mallory ignition, remote oil filter
Reply With Quote
  #22  
Old 6th August 2013
mikethebike61 mikethebike61 is offline
Banned
 
Join Date: Jan 2011
Location: Paradise
Posts: 2,035
Sportster/Buell Model: xlch
Sportster/Buell Year: 1977
Other Motorcycle Model: BMW K-1200/GT
Other Motorcycle Year: 2004
Reputation: 13333
mikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of light
Default

Quote:
Originally Posted by dragsta View Post
all of these bikes get carbon buildup. the question is; why is his bike dieseling when others of similar carbon buildup composition are not?

back in the land of the 70's i had a 71 pontiac that dieseled. i tried everything.... a mechanic i knew told me to "turn down the idle" and that worked.
I doubt this bike has the level of emissions equipment a 1971 automobile had. By 71 dieseling was rampant in the automobile world. One of the problems was the 'decel' valve that held the throttle open for 3-5 seconds after you lifted. This was to allow the engine enough air to burn the fuel that follows the air.
Reply With Quote
  #23  
Old 6th August 2013
Tom Beckner Tom Beckner is offline
Harley Engineer
 
Join Date: Aug 2009
Location: Virginia
Posts: 320
Sportster/Buell Model: XLH 883/HP 1250
Sportster/Buell Year: 2002
Reputation: 67038
Tom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud ofTom Beckner has much to be proud of
Default

Quote:
Originally Posted by carbineken View Post
My idle is set at roughly 1100-1200 and I don't sit around at idle very much.
I don't know how your motor is set up or which cams you're using, but
1200 seems unnecessarily high to me. I could be wrong.

Too much throttle opening at shut down aggravates the problem, as advised by others.

In hot weather, adjust the idle mixture to attain peak RPM. No exception.
Reduce the idle speed to 1100 or less, and see if that helps.

Changing the ignition points won't affect anything. Changing the timing will.

Advance the initial timing and less throttle position is required to maintain
desired idle speed. Retard initial timing, and greater throttle position is required.

Tom Beckner
Reply With Quote
  #24  
Old 6th August 2013
SHIPCHIEF's Avatar
SHIPCHIEF SHIPCHIEF is offline
Know It All
 
Join Date: Dec 2008
Posts: 163
Sportster/Buell Model: xlh 1000
Sportster/Buell Year: 1984
Sportster/Buell Model #2: 'Big Sportster' FXR
Sportster/Buell Year #2: 1988
Other Motorcycle Model: Ural Patrol, Yamaha XS650
Other Motorcycle Year: 2003
Reputation: 10
SHIPCHIEF is an unknown quantity at this point
Default

I'm starting to get the impression that you installed 10:1 pistons during your last teardown?
Anyway, if your timing is spot on, then your mixture might be a bit rich if you bumped up the compression ratio? Are the tailpipes black? What color are your plugs? If you are running a bit rich now, then a carbon build up would be expected. If running higher compression, then colder plugs would be indicated, the plugs could be the hot spot in the combustion chamber instead of or along with carbon build up.
I have a 1984 with the extra thick headgasket. I've got an extra set of cylinders & heads, so I was thinking of switching to 10:1 pistons, or maybe going the safe route and just using the thinner standard headgaskets with the 9:1 pistons. Right now the compression on my bike is so low that it is hard to start. It slowly blubbers to life while the engine cranks over fast.
I believe a combination of low compression and long duration cams ends up with vey low "Corrected Compression" hence, fast cranking and weak starting.
If you have stock cams and high compression pistons, along with stock spark plugs, then dieseling sounds possible in hot weather. However, your low end torque must be impressive!!
__________________
Most engines don't die a natural death, they are murdered.
Reply With Quote
  #25  
Old 6th August 2013
carbineken's Avatar
carbineken carbineken is offline
Harley Engineer
 
Join Date: Sep 2010
Location: At the lake
Posts: 345
Sportster/Buell Model: XLH
Sportster/Buell Year: 1974
Reputation: 796
carbineken will become famous soon enoughcarbineken will become famous soon enoughcarbineken will become famous soon enoughcarbineken will become famous soon enoughcarbineken will become famous soon enoughcarbineken will become famous soon enoughcarbineken will become famous soon enough
Default

Okay...run down on my bike. '74 XLH, no more e-start,kick only. Mikuni carb, Karata belt primary,23/51 sprockets,stock points ignition/coil,'P' cams. I believe the pistons are 9:1..I didn't intentionally install higher comp pistons. .030 over bore, left the cylinder base gaskets out and used copper head gaskets...IDK their thickness. Full length 1.75" slash cut drag pipes w/lollipops. Had Ultima EI/NGK BPR6 plugs in it...dieseling never happened. Started having issues with ignition just stopping....don't know if it was the EI or the coil just swapped points and stock coil back into it. Running NGK B6L plugs in it now.

Gonna be triple digits here when I get home but will try to get a good plug chop and upload some pics.
Reply With Quote
Know Thy Hog

  #26  
Old 6th August 2013
mikethebike61 mikethebike61 is offline
Banned
 
Join Date: Jan 2011
Location: Paradise
Posts: 2,035
Sportster/Buell Model: xlch
Sportster/Buell Year: 1977
Other Motorcycle Model: BMW K-1200/GT
Other Motorcycle Year: 2004
Reputation: 13333
mikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of light
Default

Quote:
Originally Posted by SHIPCHIEF View Post
the 9:1 pistons. Right now the compression on my bike is so low that it is hard to start. It slowly blubbers to life while the engine cranks over fast.
I believe a combination of low compression and long duration cams ends up with vey low "Corrected Compression" hence, fast cranking and weak starting.
If you have stock cams and high compression pistons, along with stock spark plugs, then dieseling sounds possible in hot weather. However, your low end torque must be impressive!!

It isn't the 9/1 static C/R pistons that are the reason your bike only 'blubbers to life'. My 77 is 9/1 and it does not 'blubber to life'.
Reply With Quote
  #27  
Old 7th August 2013
IronMick's Avatar
IronMick IronMick is offline
Rider Of The Iron Steed
 
Join Date: Dec 2003
Location: London, ON Canada
Posts: 27,101
Sportster/Buell Model: XLH
Sportster/Buell Year: 1978
Reputation: 130507
IronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud ofIronMick has much to be proud of
Default

Quote:
Originally Posted by carbineken View Post
... My idle is set at roughly 1100-1200 ...
That is too high. Try 950 to 1050.
Reply With Quote
  #28  
Old 7th August 2013
Freeme Freeme is offline
Know It All
 
Join Date: Mar 2013
Location: Southern Maryland
Posts: 185
Sportster/Buell Model: XLH
Sportster/Buell Year: 1978
Other Motorcycle Model: Ultra Classic
Other Motorcycle Year: 2008
Reputation: 3245
Freeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the roughFreeme is a jewel in the rough
Default

Check your ignition key switch. Your problem may be electrical. It is common for these switches to fail.
Reply With Quote
  #29  
Old 7th August 2013
dragsta dragsta is offline
Banned
 
Join Date: May 2013
Posts: 409
Sportster/Buell Model: XLH
Sportster/Buell Year: 1979
Sportster/Buell Year #2: 1979
Other Motorcycle Model: superglide
Other Motorcycle Year: 2004
Reputation: 4478
dragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nicedragsta is just really nice
Default

Quote:
Originally Posted by IronMick View Post
That is too high. Try 950 to 1050.
+1

for some strange reason he refuses to turn his idle down. this is likely the simple-fix of the decade.
Reply With Quote
  #30  
Old 7th August 2013
mikethebike61 mikethebike61 is offline
Banned
 
Join Date: Jan 2011
Location: Paradise
Posts: 2,035
Sportster/Buell Model: xlch
Sportster/Buell Year: 1977
Other Motorcycle Model: BMW K-1200/GT
Other Motorcycle Year: 2004
Reputation: 13333
mikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of lightmikethebike61 is a glorious beacon of light
Default

Quote:
Originally Posted by dragsta View Post
+1

for some strange reason he refuses to turn his idle down. this is likely the simple-fix of the decade.
That is part of the 'proper tune' I advised.
Reply With Quote
Know Thy Hog

Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
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 Off

Forum Jump


Custom Search

All times are GMT +1. The time now is 06:53.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
XL Forum - Linson Media LLC