ScrambleShine
Member
I'm trying to find out if this is a common problem with modern classics, water-cooled twins, Bonnevilles, Street Scramblers, and if anyone has any helpful suggestions.
My 2019 Street Scrambler suddenly developed a weird idle speed problem. For two years and 15K miles, it always idled at 1000 RPM after warm up. About a week ago, I noticed it seemed to be hanging at around 2000 RPM for several seconds as I was slowing to stop. Then I noticed that when it settled back down to idle at stops, it would hover around 1350-1400 RPM. Upon start-up, when warm, it runs at 2000 RPM for a few minutes before settling back to 1400 or so at idle. Took it to the Triumph dealer where I bought it. They said they got it to idle at around 1000 RPM, but noticed that the oil was "thin and frothy" and might be causing it. Suggested an oil change. After oil change, they reported that it was doing it again and idling extremely high (2000 RPM) at start up, and said they'd need to keep it and maybe get in touch with Triumph.
Main problem is, in low-speed situations, where you have to feather the clutch to maintain speed below 10 mph, the bike feels like it wants to run away. The bike has an "assist clutch" feature which helps prevent stalling on take-off, but it does this by adding about 300 rpm as the clutch approaches the friction zone. This means that, while using the friction zone to maintain low speed, the motor is running at 1700-1900 rpm instead of the normal 1300 rpm. When idling with clutch all the way out in first gear, that's the difference between 10 mph and 18 mph.
Here's what the Haynes Manual (for all the 2016-2019 Bonnevilles) says about idle speed: "Engine idle speed is controlled electronically and cannot be adjusted manually. If the idle speed is not steady and correct when the engine is at normal temperature, check the air filter is clean, the spark plugs are clean, and their gaps are correct, the valve clearances are correct, and on 1200 engines the throttle bodies are synchronized. Also check for loose bolts and leaking seals between the throttle body, the intake manifold, and the cylinder head on 900 engines, and for loose clamps or bolts between the throttle bodies, the intake ducts, and the cylinder head on 1200 engines--any extra air getting in will affect the idle speed. If all is good so far check cylinder compression. If no problem can be found take the bike to a Triumph dealer for assessment of the idle speed control system and the throttle system using the diagnostic tester."
I have a feeling that the problem with my bike involves something loose somewhere that is allowing air into the system, which may also explain the frothy oil. The bike is under warranty for three more months.
Which is more likely:
A. The Triumph dealer checks thoroughly for all the possible causes listed in the Haynes manual, finds the loose bolt or seal, and fixes it, making me that much more willing to buy another Triumph motorcycle in the near future,
or
B. The Triumph dealer keeps the bike for another week and then tells me, "It's normal for this bike to do that."
My 2019 Street Scrambler suddenly developed a weird idle speed problem. For two years and 15K miles, it always idled at 1000 RPM after warm up. About a week ago, I noticed it seemed to be hanging at around 2000 RPM for several seconds as I was slowing to stop. Then I noticed that when it settled back down to idle at stops, it would hover around 1350-1400 RPM. Upon start-up, when warm, it runs at 2000 RPM for a few minutes before settling back to 1400 or so at idle. Took it to the Triumph dealer where I bought it. They said they got it to idle at around 1000 RPM, but noticed that the oil was "thin and frothy" and might be causing it. Suggested an oil change. After oil change, they reported that it was doing it again and idling extremely high (2000 RPM) at start up, and said they'd need to keep it and maybe get in touch with Triumph.
Main problem is, in low-speed situations, where you have to feather the clutch to maintain speed below 10 mph, the bike feels like it wants to run away. The bike has an "assist clutch" feature which helps prevent stalling on take-off, but it does this by adding about 300 rpm as the clutch approaches the friction zone. This means that, while using the friction zone to maintain low speed, the motor is running at 1700-1900 rpm instead of the normal 1300 rpm. When idling with clutch all the way out in first gear, that's the difference between 10 mph and 18 mph.
Here's what the Haynes Manual (for all the 2016-2019 Bonnevilles) says about idle speed: "Engine idle speed is controlled electronically and cannot be adjusted manually. If the idle speed is not steady and correct when the engine is at normal temperature, check the air filter is clean, the spark plugs are clean, and their gaps are correct, the valve clearances are correct, and on 1200 engines the throttle bodies are synchronized. Also check for loose bolts and leaking seals between the throttle body, the intake manifold, and the cylinder head on 900 engines, and for loose clamps or bolts between the throttle bodies, the intake ducts, and the cylinder head on 1200 engines--any extra air getting in will affect the idle speed. If all is good so far check cylinder compression. If no problem can be found take the bike to a Triumph dealer for assessment of the idle speed control system and the throttle system using the diagnostic tester."
I have a feeling that the problem with my bike involves something loose somewhere that is allowing air into the system, which may also explain the frothy oil. The bike is under warranty for three more months.
Which is more likely:
A. The Triumph dealer checks thoroughly for all the possible causes listed in the Haynes manual, finds the loose bolt or seal, and fixes it, making me that much more willing to buy another Triumph motorcycle in the near future,
or
B. The Triumph dealer keeps the bike for another week and then tells me, "It's normal for this bike to do that."
