Dafeimao85
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Hi All Happy 2025
Does anyone know if the busa has a limp mode function?
Does anyone know if the busa has a limp mode function?
Question on Gen 2 busa Limp Mode
- Thread starter Dafeimao85
- Start date
No, the Gen1 and Gen2 do not.
Dafeimao85
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I am having a big headache
Why the bike bog at around 4k rpm... Without giving off any error.
Does the ecm detect fuel line pressure. With this symptoms my bets are now on the fuel pump which I recently replaced
I am not sure, as you have had so many issues with the bike, but if the secondary throttle plates have been removed, it will cause it to bog at lower rpms, and run better at higher rpms.
The bike needs to be tuned if they are gone, but performs better with them in.
Dafeimao85
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Ya my bike is getting more and more badass and weird...
I have done almost overhaul and handful sensor replacement.
Sigh... Spend almost 2k for all these yet it still fall sick
I don't know any of the history of your bike, but if you replaced the fuel pump, did you replace the filter? The big plastic piece the pump fits into, not the sock on the bottom of the pump. The Gen2's are getting old enough the filters are failing. I've seen it more than once. If the bike recovers from the bog and then revs fine, the filter likely isn't the problem.
Dafeimao85
Registered
Hi Dennis and all.
I did not replace the metal strainer. It was not sold separately. Did saw on ebay for after market type. FYI gen 2 2014 onwards the fuel pump metal strainer is on the top (same like gsxr 750) No longer on the side.
So I just open up disassemble make sure everything is okay and reassemble and I also change back my old pump pressure regulator.
By chance I forget to put in 1 O Ring Seal on the pump discharge, which result unable to start. I then re assemble once more. The abnormality I notice is the pump body is hot with that few seconds of priming and running for start. If the pump is unable to suck in any fuel, I could understand. But the O ring I forget to place back was on the discharge. It should just continually recirculate within the fuel tank. The pump should not be hot for that few seconds of running.
Then I took the bike for a test run and was able to Rev past 8k rpm easily. Then after 20miles, it suddenly bog down to limit at 3k rpm.
Hence I believe the fuel pump had sort of partial malfunction and result in high temp which then cause a vapour lock or the suction strainer is badly plug but from the look of it which I don't think so.
I had contacted Quantum Fuel Pump and explain the situation. They send me a new pump immediately. I wonder is it a malfunction that they knew.
Well if thats the case, it means I need to start save up for a Suzuki pump before the replacement pump fail...
Old bikes that have sat around un-ridden or have been left out in the weather can have a multitude of issues. I read your other posts @Dafeimao85 and I see you discovered wiring connectors that were corroded, a classic sign of a bike left out in the weather. Unfortunately that was only discovered after you went and replaced parts thinking they were at fault. Outdoors insects can make homes in unusual places too, blocking up breathers and causing many issues. In the old days I saw a bike with a fuel issue that was caused by an ant crawling into the air-box then down a pressure equalization hose to a carburetor and effecting the float level. It was only found by pure chance.
Your shop also found untold carbon buildup on the valves, (from my experience) caused by running an engine on low grade fuel like 91 and or just putting around town and never taking the revs up high. The same principle applies to any engine, they need to get hot and fast to burn up and blast out the carbon. How you do that in tiny Singapore I don't know but I regularly run in a gear lower than needed, just to keep the engine at a higher RPM. It's a shame you've had these problems, the Gen-II is a super reliable bike, but even the best will have issues if not cared for over time. Let's hope you're at the end of the issues soon. Next time follow the golden rule, Low Mileage
Your shop also found untold carbon buildup on the valves, (from my experience) caused by running an engine on low grade fuel like 91 and or just putting around town and never taking the revs up high. The same principle applies to any engine, they need to get hot and fast to burn up and blast out the carbon. How you do that in tiny Singapore I don't know but I regularly run in a gear lower than needed, just to keep the engine at a higher RPM. It's a shame you've had these problems, the Gen-II is a super reliable bike, but even the best will have issues if not cared for over time. Let's hope you're at the end of the issues soon. Next time follow the golden rule, Low Mileage
Dafeimao85
Registered
Hi Oz22,Old bikes that have sat around un-ridden or have been left out in the weather can have a multitude of issues. I read your other posts @Dafeimao85 and I see you discovered wiring connectors that were corroded, a classic sign of a bike left out in the weather. Unfortunately that was only discovered after you went and replaced parts thinking they were at fault. Outdoors insects can make homes in unusual places too, blocking up breathers and causing many issues. In the old days I saw a bike with a fuel issue that was caused by an ant crawling into the air-box then down a pressure equalization hose to a carburetor and effecting the float level. It was only found by pure chance.
Your shop also found untold carbon buildup on the valves, (from my experience) caused by running an engine on low grade fuel like 91 and or just putting around town and never taking the revs up high. The same principle applies to any engine, they need to get hot and fast to burn up and blast out the carbon. How you do that in tiny Singapore I don't know but I regularly run in a gear lower than needed, just to keep the engine at a higher RPM. It's a shame you've had these problems, the Gen-II is a super reliable bike, but even the best will have issues if not cared for over time. Let's hope you're at the end of the issues soon. Next time follow the golden rule, Low Mileage
Thanks for the following of my busa story
Yea, Singapore road limit speed is only 56mph on the express way and 31mph on the non expressway road.
So usually we ride to Malaysia where they have less speed camera and long distance road. There is where I always get my busa to 186mph
Reliability was the reason why I brought a busa. But so many unfortunately case happens.
I hope once the fuel pump replace and that's the end and let me allocate the budge to modification.
The budget to change a steering damper, r1 fast throttle and brocks clutch are now use for the repair
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