Running rough when cold
Road Warrior
Joined: Mar 2009
Posts: 1,471
Likes: 9
From: Toledo, Ohio
I bought my first evo this year with 10k original miles, and it's been like yours from day one. Some days worse/better than others. Options are patience or go back to twinkieland…I chose patience. Still not convinced yet that I need carb work? Differing opinions on here when I too asked.
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Novice
Joined: May 2012
Posts: 16
Likes: 0
From: S.E. PA.
That's why I am considering this a problem. For over a year I'd start up with full choke let it idle while I had a smoke push to half choke and go, no problem. Now it's running really rough for at least a mile down the road using the same procedure.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
You replaced the plugs recently?....Evo's are funny about plugs....Iridium NGK's work best in my experience.
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
Not always, the motor can deal with issues better when its warm (ever heated up the plug on a 2-stroke lawnmower to get it to start?)
Any Evo that comes to me with starting or misfire probs gets new plugs before any diagnostics take place.....cures at least 25% of them straight away. Iridiums will last for ever but any fouling or wear on a non-iridium plug can cause a heap of problems.
Yesterday I did a home visit to a sick 1987 Softie......running on one cylinder....new plugs and it was fixed :-) Then I re-adjusted the S&S carby so it didn't foul the plugs at idle and the customer was 75 bucks poorer (inc labour) but 100% happier....wish it always was that simple!
BTW you can't always clean a fouled plug sufficiently for an Evo to run well on it, so new is always the better option, then cure the fault that makes them foul in the first place.
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Novice
Joined: May 2012
Posts: 16
Likes: 0
From: S.E. PA.
when I fired the bike up today. choke out all the way fired right up but sounded like one cylinder severely miss firing. When I increased throttle the miss would even out. after a couple min. pushed choke all the way in idled okay still didn't sound quite right. Let it idle for 5-10 min. then went for a ride, still ran really rough for about a mile including backfiring when I opened the throttle.
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Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
when I fired the bike up today. choke out all the way fired right up but sounded like one cylinder severely miss firing. When I increased throttle the miss would even out. after a couple min. pushed choke all the way in idled okay still didn't sound quite right. Let it idle for 5-10 min. then went for a ride, still ran really rough for about a mile including backfiring when I opened the throttle.
Dodgy plugs or air leak would be my first thoughts on that one.
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Novice
Joined: May 2012
Posts: 16
Likes: 0
From: S.E. PA.
Also plugs and air filter were replaced after this first started. The problem seems to be getting worse. I did pull the plugs the other day and there was black carbon on the plugs, so I cleaned them off also pulled the air cleaner and sprayed carb cleaner in tto the carb. Did'nt seem to make a difference.