Suzuki SV650 Riders Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
Hi all, this is probably super weird and rare problem, but let me try to explain:
After riding for at least 20 minutes, engine is at good operating temperature (around 85 C), when I accelerate on one specific bridge on my way home coming out of the roundabout (so I'm doing this almost all the times at very similar throttle and gear) and then shut the throttle off on the slope downhill (leading to traffic lights) I would expect the bike to engine brake, BUT sometimes, it just keeps on slowly coasting and decelerating, even keeping in revs if I clutch-in at the moment (around 2000 rpm, really close to my adjusted fast idle). I have seen that happen many times now, but not always. What I see when looking at the left side is the secondary throttle keeping open thus pushing the fast idle cam keeping the primary throttle above idle. The bike hangs in the revs for few seconds and then swiftly just drops back to correct idle.

I have checked:
  • air intake temperature sensor
  • coolant temperature sensor
  • intake pressure sensor
  • primary throttle position sensor
all seems to be working correctly (I need to double check the TPS for linearity though)
Throttle cables do return easy and the primary throttle is most likely not the issue.

Secondary plates are balanced, servo seems to be working (hard to check that one). I have adjusted the fast idle so that the system stops fast idling around 50 C, I can pull the set screw a bit out but then the fast idle seems too slow on cold start.

Does anyone have an idea where to look? I do suspect secondary throttle position sensor. Or should I have look at balancing my throttles? The bike doesn't give any error codes... I'm lost there. And it does that thing just sometimes.
 

·
Registered
Joined
·
20 Posts
i don't fully understand the issue tbh, but what's your engine idle at? I had at 1400-ish or more, and I was having issues with the bike getting stuck at around 3000RPM. Adjusting it closer to 1200 fixed that..
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #4 ·
i don't fully understand the issue tbh, but what's your engine idle at? I had at 1400-ish or more, and I was having issues with the bike getting stuck at around 3000RPM. Adjusting it closer to 1200 fixed that..
Ah, around 1400 here as well. Good info, will try that!

Check for vacuum leaks.
That is a good idea, I haven't checked that.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #5 ·
Just a quick update - as suggested by Golden Saint I have checked my idle after longer ride and turned it down to 1200-1300 rpm (it was around 1500 rpm after getting properly warmed up). Problem disappeared. Makes me wonder about the cause being me increasing the idle set screw at the beginning of the winter as the bike began to idle far too low and I haven't checked the TPS after that. Maybe?

Experience learned. Keep your idle down.
 
1 - 5 of 5 Posts
Top