Idle surge/ hang

Jeff06098

.040 Over
Joined
Mar 6, 2021
Messages
61
Location
Winsted, CT
Ride
2005 Triumph Rocket
Hey guys. I bought my 2005 classic 2 weeks ago. I’ve put about 400 miles on it in some not so perfect spring weather.
I noticed once before it seemed like the idle hung high when I was pulling in my driveway but chalked it up to me not letting off the throttle fully. Today I did a little over 100 miles. At the end of my ride I noticed that when I went to shift gears it didn’t seem to be idling down correctly. What I found was that it was sitting at around 1800 RPMs when I went to shift. If I pulled the clutch it surged to 2200~ then settled back to 1800 then 10~ seconds later it would settle down to its normal 850 idle rpm. Giving it a rev seemed to do nothing to help. I decided to pull into a boat launch and turn it off to see what would happen. Sat there maybe 5 minutes and fired it up. No problems. Rode the 2 miles home from there and no issues.
I’ve done a bit of reading on here and have quite a places to look. The only think is I’m not sure where to start. I’ll lube all the linkages but it doesn’t seem like that’s the issue with how it’s behaving.
The bike has 14,500 miles.
In 2017 at 10,200 miles the Idle speed controller, throttle position sensors, idle speed controller and air pressure sensor where replaced by the dealer. In 2018 the bike had a no start condition. Prior owner had it brought to an independent shop. They replaced the fuel tank and filter, cleaned injectors, swapped out a relay (doesn’t say which) and flushed brake fluid and replaced lines.
In 2020 new tires and wheel bearing where done.
Prior second owner bought the bike not running. It has sat for a while. He also did a bunch of work to it himself but I don’t know all of that. Anyway bike runs great now other than this idle issue.

Do any of you experts out there have any ideas where I should start to look?
I do have tuneecu but I haven’t plugged into the bine yet. I’ve always run carbureted bikes so all the electronics is new fun for me.
 
Funny, in a way. My 05 with a 2015 engine, did the same exact thing, the other day. After a few miles, it straightened out, and was back to normal. What was the cause? I dunno. I will give the throttle bodies/linkage, a blast of WD-40, and hope it does not return. o_O
 
Hello Jeff, I am no expert but I too have had the issue you speak of. The first time was around 33K miles. The plastic washers at the front of the injector assembly had worn out due to road grime. Even after cleaning them, they were too worn out to allow the throttle spring to pull the throttle back to idle. I was revving around 3K RPMs at idle. I had to replace the plastic bits from a cannibalized fuel manifold.
Flash forward to last year, @warp9.9 was fiddling with my stepper motor and found the darn thing is worn out, Guess why? Road grime once more. He cleaned the area well and disconnected the plunger from the throttle block. That smoothed out the surging I was experiencing. I had to hold slight pressure at idle to keep the bike running.
I recommend using some WD40 or the like and clean the heck out of all the linkage at the front of the Fuel manifold. Take some stuff off to get in there good. Your bike is barely even used with that low mileage, so it may still be an easy fix with cleaning.
 
Hello Jeff, I am no expert but I too have had the issue you speak of. The first time was around 33K miles. The plastic washers at the front of the injector assembly had worn out due to road grime. Even after cleaning them, they were too worn out to allow the throttle spring to pull the throttle back to idle. I was revving around 3K RPMs at idle. I had to replace the plastic bits from a cannibalized fuel manifold.
Flash forward to last year, @warp9.9 was fiddling with my stepper motor and found the darn thing is worn out, Guess why? Road grime once more. He cleaned the area well and disconnected the plunger from the throttle block. That smoothed out the surging I was experiencing. I had to hold slight pressure at idle to keep the bike running.
I recommend using some WD40 or the like and clean the heck out of all the linkage at the front of the Fuel manifold. Take some stuff off to get in there good. Your bike is barely even used with that low mileage, so it may still be an easy fix with cleaning.
Thanks I don’t expect it to be to difficult. Everything’s been replaced. I forgot it had new coils and intake boots as well. Prior owner had over $3500 into it and I bought it for $4500. Considered it a pretty good steal.
 
Funny, in a way. My 05 with a 2015 engine, did the same exact thing, the other day. After a few miles, it straightened out, and was back to normal. What was the cause? I dunno. I will give the throttle bodies/linkage, a blast of WD-40, and hope it does not return. o_O

also peel back the rubber on the stepper motor and wd that.
 
Funny, in a way. My 05 with a 2015 engine, did the same exact thing, the other day. After a few miles, it straightened out, and was back to normal. What was the cause? I dunno. I will give the throttle bodies/linkage, a blast of WD-40, and hope it does not return. o_O
That's what fixed mine as well. I really did not know what I was doing when I sprayed the heck out of the area of the lower throttle cable adjustment and the hang up went away and has never been back. My kind of repair.👍
 
Hey guys. I bought my 2005 classic 2 weeks ago. I’ve put about 400 miles on it in some not so perfect spring weather.
I noticed once before it seemed like the idle hung high when I was pulling in my driveway but chalked it up to me not letting off the throttle fully. Today I did a little over 100 miles. At the end of my ride I noticed that when I went to shift gears it didn’t seem to be idling down correctly. What I found was that it was sitting at around 1800 RPMs when I went to shift. If I pulled the clutch it surged to 2200~ then settled back to 1800 then 10~ seconds later it would settle down to its normal 850 idle rpm. Giving it a rev seemed to do nothing to help. I decided to pull into a boat launch and turn it off to see what would happen. Sat there maybe 5 minutes and fired it up. No problems. Rode the 2 miles home from there and no issues.
I’ve done a bit of reading on here and have quite a places to look. The only think is I’m not sure where to start. I’ll lube all the linkages but it doesn’t seem like that’s the issue with how it’s behaving.
The bike has 14,500 miles.
In 2017 at 10,200 miles the Idle speed controller, throttle position sensors, idle speed controller and air pressure sensor where replaced by the dealer. In 2018 the bike had a no start condition. Prior owner had it brought to an independent shop. They replaced the fuel tank and filter, cleaned injectors, swapped out a relay (doesn’t say which) and flushed brake fluid and replaced lines.
In 2020 new tires and wheel bearing where done.
Prior second owner bought the bike not running. It has sat for a while. He also did a bunch of work to it himself but I don’t know all of that. Anyway bike runs great now other than this idle issue.

Do any of you experts out there have any ideas where I should start to look?
I do have tuneecu but I haven’t plugged into the bine yet. I’ve always run carbureted bikes so all the electronics is new fun for me.
Hi

Did you figure out what was the problem?
 
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