r/Fixxit • u/BDPE_anon • 4h ago
Unsolved Suzuki gsx 650 F 2008
Suzuki gsx 650 F 2008
Hi everyone,
I'm having a problem with my motorcycle and I'm honestly running out of ideas.
The problem first started when I was riding at around 130 km/h (80 mph) in 4th gear. The bike started jerking/sputtering and wouldn't accelerate past 130 km/h. However, when I shifted into 5th gear, it was able to accelerate further.
A few weeks later, I went to get some food. Since I was at a drive-through, I started and stopped the bike several times while waiting.
When I got my food and wanted to leave, I noticed that the exhaust suddenly sounded very strange. There was a deep, irregular popping/pulsing sound coming directly from the exhaust (I have an aftermarket exhaust). It almost sounded tractor-like. The bike also had significantly less power.
At idle, the engine was running very rough. The RPM kept fluctuating between roughly 1,000 and 1,200 RPM, almost as if I was slightly opening the throttle.
When I started riding, I couldn't go faster than about 90 km/h (56 mph). At that speed, the bike was sputtering and jerking extremely badly.
The motorcycle was also restricted to A2 / 48 hp (35 kW). As part of troubleshooting, I have now removed the A2 restriction to see whether the restriction itself could have been causing the problem. However, removing it did not solve the issue.
Since then, I have replaced/serviced the following:
All 4 fuel injectors
All 4 spark plugs
All 4 ignition coils
Cleaned the throttle bodies
Cleaned the ISC (Idle Speed Control) and changed the Sensor of the isc
Replaced the stator and regulator
Replaced the fuel pump strainer/"teabag" filter
Replaced the small fuel delivery/pump unit inside the fuel pump assembly
Cleaned the small plastic part at the bottom of the fuel pump assembly with throttle body cleaner
Changed the engine oil and oil filter
Replaced the air filter
Removed the A2 / 48 hp restriction for troubleshooting
There are no fault codes showing on the display.
After replacing and cleaning all of these parts, the situation is now even stranger:
The bike will usually only start if I give it some throttle, and then it immediately dies again when I release the throttle.
If I manage to get it to stay running, the idle is extremely low, around 700 RPM. Occasionally it stays running at around 1,000 RPM, but after a short time it drops back down to around 700–800 RPM.
The headlight also flickers slightly while the engine is running.
About 8 out of 10 times the engine stalls, and it generally won't stay running without me giving it throttle.
There are still no fault codes.
I'm completely stuck at this point and don't know what else to check. Any ideas about what could be causing this or what I should test next would be greatly appreciated.