Lean misfire at low cruise speed when hot. Solution?
- Thread starter rickerho
- Start date
These bikes run pretty lean to start with, and when you add the two bro exhaust, you probably leaned it out even more etc. Are you running the stock air filter or a K&N (even leaner) etc.
Before I would start throwing money at it, I would lift the tank, and replace the fuel injector lines, clean the 5 way tee, and run some seafoam and mmo through the system. You could just have some minor obstructions in the lines (very common) It would only take about an hour of your time, and would not cost you anything to rule that out.
Igofar
Before I would start throwing money at it, I would lift the tank, and replace the fuel injector lines, clean the 5 way tee, and run some seafoam and mmo through the system. You could just have some minor obstructions in the lines (very common) It would only take about an hour of your time, and would not cost you anything to rule that out.
Igofar
Hi, thanks for the advice. Tee and vacuumed lines good. By injector lines you mean the high pressure ones? One thing Im wondering is if the fuel pressure regulator was replaced with higher pressure one by previous owner if that might cause problem? The slight miss is there even in neutral if I bring rpm up to about 3000...when ridding its there anytime there's no load. Its fairly minor but I'd like it gone. Oxygen sensor? Miss is not there when bike is cold do I assume its a lean misfire?
Thanks in advance to anyone with any more ideas.
Thanks in advance to anyone with any more ideas.
The first thing that I would try is to add some good quality injector cleaner to the petrol. We have a great product here in Australia , it is called F 10, and it is added at the rate of 200 Ml per 80 liters of fuel, this will remove any gum and or carbon from the fuel system and it does not harm any other system components. I have been using it for years in a multitude of vehicles.As well as in all of my bikes , both carburetor, and fuel injected.
Perhaps here is some similar type of product available locally for you.
The situation that you describe suggest to me that part if not all of your problems could be partly obstructed pintles in the injectors.
Hope that this helps
Cheers , Winston, Northampton, Western Australia
Perhaps here is some similar type of product available locally for you.
The situation that you describe suggest to me that part if not all of your problems could be partly obstructed pintles in the injectors.
Hope that this helps
Cheers , Winston, Northampton, Western Australia
After doing a bunch of reading. Sounds like a slight miss or or stumble at cruise speed especially around 3000-4500 RPM that goes away with a bit more throttle is common on these bikes. I guess its more noticable with Two Brothers exhaust and K&N air filter. Ive read about putting higher PSI fuel regulator to richen up...but cant find one or any other aftermarket device to richen fuel. I really dont want to put stock exhaust back on. Any ideas?
I had a "performance" muffler on my ST1300 for a couple years. Decided i didn't like the noise, so put the original pipes back on. WOW, it runs so much better. As said above, these are lean to begin with so any modifications are going to take away from throttle response. If you want to pursue more airflow, you'll need to match it with a Techlusion or similar box to add fuel.
BakerBoy
It's all small stuff.
True, it is a 'feature' of the bike's ECU mapping. No, you cannot richen it by changing the FPR or air filter or exhaust or ... or ... The ECU controls fuel mixture by reading the oxygen sensor in the exhaust pipe ... it is what it is.
Hi, so I checked 5way way t again put stick air filter and exhaust back on. Still has this cruise speed misfire. I just did a 3000mile trip and notice thrones of left pipe is light tan and inside of right pipe is black wondering if this is an indicator of too lean or rich and why tge in balance?