Hello everyone. I have a 2004 ST1300, I have noticed a power surge where I can suddenly feel an sudden but slight engine power loss then I can feel the power slowly come back, it is more noticeable at higher altitudes (above 3000 Ft.) at sea level "where I live" the power surge seems less noticeable, has anyone had or have this same problem? has anyone been able to diagnose and fix the problem?
ST1300 power surge
- Thread starter Mentalfatigue
- Start date
wjbertrand
Ventura Highway
What RPM? If it's happening around 3500, it may be the lean spot in the fuel mapping. I fixed that with a higher pressure fuel pressure regulator. 58 vs. the OEM 50 PSI. I think New Enough is still selling them.
Thank you for your reply, sorry I put the message in the wrong forum area I tried to delete it then go to the correct forum. I don't remember it surging at a particular RPM. I can check that next time I ride. I have been wondering if the Fuel Pressure Regulator might be a possible cause. I will place a new post in the correct post area. thank you again.
- Joined
- May 6, 2008
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- 6,175
- Age
- 66
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- Lompoc, California
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- 07 & 12 ST1300A
- SPOT
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- STOC #
- 8057
Re: ST engine Power surge
Here are some links with what sounds like the same problem
https://www.st-owners.com/forums/showthread.php?96768-ST1300-Engine-Replacement&highlight=
https://www.st-owners.com/forums/showthread.php?102183-Wisdom-of-the-Forum-needed&highlight=
Good luck
Here are some links with what sounds like the same problem
https://www.st-owners.com/forums/showthread.php?96768-ST1300-Engine-Replacement&highlight=
https://www.st-owners.com/forums/showthread.php?102183-Wisdom-of-the-Forum-needed&highlight=
Good luck
Blrfl
Natural Rider Enhancement
Get to know your bike's torque curve and make note of whether or not what you're seeing corresponds with the dip and flat spot in the 3-4,000 RPM range that Jeff mentioned above.
Your intro post didn't mention what you rode before, but there have been a number of new owners who've come from varying kinds of twins, rode the ST as if its V4 behaved the same way and had problems. I ran into the same thing and was a lot happier once I made the adjustment.
--Mark
Your intro post didn't mention what you rode before, but there have been a number of new owners who've come from varying kinds of twins, rode the ST as if its V4 behaved the same way and had problems. I ran into the same thing and was a lot happier once I made the adjustment.
--Mark
BakerBoy
It's all small stuff.
MF- (that just doesn't sound like a good abbreviation!)
I'm pretty sensitive to the bike's power, surge, and related behaviors as mine has a technical problem with strong surging at high temps, high altitude, which I can't get identified.
If you've got the throttle barely cracked and are cruising along, the oxygen sensor and ECU are continuously hunting for the 'right' fuel mixture [ie, lean]--you can notice the ever-so-slight sensation as cylinders don't fire. Pdfruth has hooked up a scope to this part of the bike's circuit and he says it is constantly hunting, even at constant throttle. If this is what you are experiencing it is normal, and it feels a bit like the engine management system (which purposely shuts off or turns on cylinders) in a GM V-6 in level, low-power cruise, such as when the cruise control is set. An ever so slight movement of the throttle will change that feeling (but then it does it again). The ST does not have engine/cylinder management, however at very low power the lean mapping is such that it barely fires.
If you're experiencing a strong surging/hammering of power, well that's another issue.
I'm pretty sensitive to the bike's power, surge, and related behaviors as mine has a technical problem with strong surging at high temps, high altitude, which I can't get identified.
If you've got the throttle barely cracked and are cruising along, the oxygen sensor and ECU are continuously hunting for the 'right' fuel mixture [ie, lean]--you can notice the ever-so-slight sensation as cylinders don't fire. Pdfruth has hooked up a scope to this part of the bike's circuit and he says it is constantly hunting, even at constant throttle. If this is what you are experiencing it is normal, and it feels a bit like the engine management system (which purposely shuts off or turns on cylinders) in a GM V-6 in level, low-power cruise, such as when the cruise control is set. An ever so slight movement of the throttle will change that feeling (but then it does it again). The ST does not have engine/cylinder management, however at very low power the lean mapping is such that it barely fires.
If you're experiencing a strong surging/hammering of power, well that's another issue.
you explained the surge perfectly, thank you for your reply, this is the first fuel injected bike for me so I guess I need to get used to it's little differences then my old bikes with carburetors and very low tech design..
ChipSTer
Growing old, but not up!
I hate to dig up an old thread. But, has the surging problem been resolved? My wife and I noticed the same problem when we were in WeSTOC. The problem definitely affected the way we rode. I'm blaming it on the ECM trying to adjust to the constantly varying altitudes. I only tended to notice it on the stretches of road where you could hold a steady throttle. I wasn't paying attention to the RPM's but I'm assuming it was in the 3,500 to 4,000 rpm range because we were running about 60 mph when it was most noticeable. I would even watch the Fuel Injection warning light. I didn't say anything to my wife because I didn't want her to be concerned. But then later she actually asked if we should take her bike into the dealership to check out her ST. She was having the same problem! Coincidence? I don't think so.