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Discussion in 'Thumpers' started by erikhorton, Jan 26, 2021.
I still think the cat holds the bike back. It is a quiet system though.
Fingers crossed you can resolve the issue with this. I have the same behavior with my 22 and I find it super annoying. The bike lurches and it is impossible to ride the bike smoothly. I noticed it during my test ride but chalked it up to unfamiliairty with the bike. But I now have 1300 miles on it and nope it's the bike! Kawi really F'd up with the programming.
What speed, load , air temp and gear. How is the bike at 54 and above in 5th gear
I have not noticed any difference with different air temps. As to the rest I am not sure. I will get out this weekend and try to get more precise info on the behavior. I have started running in a higher gear than I normally would be in to lessen the lurch.
48mph is about as low as I would go in 5th. Mine does pull clean from 48 and above. I could try lower speeds and gears and will report back
If I remember correctly, the bike I rode exhibited the symptoms most readily when trying to cruise in 3rd gear at around 37-40 mph indicated. It would also do it in 2nd and 4th gear at that same rpm range.
That fuel cut at mid RPM...that's common across all FI bikes. It's to reduce emissions AND increase fuel efficiency. It used to be BAD on the older FI bikes of 10 years ago, but I was sure this is no longer the case with modern FI bikes. My '18 Ninja 1000 has this also, so does my VStrom 650. But neither bike displays any abruptness when throttle is re-opened and fuel is re-introduced. So I'm surprised that the '22 KLR has this characteristic. Another thing OEM's do is to maximize the time the engine runs in the Stoichiometric air to fuel ratio of 14.7 to 1. It's a razor thin margin where it's neither lean nor rich, and it's where the motor achieves best efficiency and clean emissions. But it also creates a sort of surging at part throttle in certain situations. Very annoying to ride when a motor is doing that.
I am not an expert, but this part of emissions and efficiency tuning from the manufacturer is "baked into" the ECM. It can be eliminated with a piggy back "tuner" that increases fuel values across the board. The results is a noticeably lower fuel efficiency because you're increasing fuel flow all the time in this range. Another way that tuners have eliminated the fuel cut is via direct ECM programming. That is the best way to fix it because you're not just going to let the engine run richer all the time within the range where fuel cut is being done. Yet, you're able to let the motor reach the Stoichiometric ratio at part throttle. The result is smooth throttle response without much fuel efficiency penalty. But hacking into the ECM isn't as easy nowadays.
That's the ECM programming. At steady part throttle, the ECM reads the Oxygen sensor, determines there's too much fuel in there, and leans the mixture out to put the bike into the Stoichiometric ratio of 14.7:1 air to fuel. The engine loses power, bike slows down. So rider increases throttle slightly to compensate and hold speed, then holds throttle steady. ECM reads Oxygen sensor and goes back to Stoichiometric ratio, bike slows down.....repeat...results in "surging". Happens to a lot of FI bikes. Some worse than others. But then again, many other modern bikes no longer do this. Go Figure.
Yes, I do notice a bit of surging when running at steady throttle sometimes but not nearly as annoying as the abrubt cutoff.
Ha stoichiometric had to come into this. Im testing today seat time. But the gen 3 I percieved as flawless with an odd behavior maybe 1% of my ride. Now the passenger vehicles Ive had have lean burn where the ratio can approach 18 to 1. Which net great gas mileage when kept in the zone.
The worst-case stock bikes Ive had steady cruise were a carb drz and vstar1300. The vstar was a nightmare with combined driveline lash. I think lash plays into screwing with the tune. The gen 3 likes load. But this makes sense as keeping the butterfly open. If the butterfly closes and is reopened I think manifold pressure goes all over the place. Especially being a thumper. Reminds me of bouncing in a bobcat. Once it starts its hard to stop. So my remedy day one was dont close the throttle and reopen. This might not be an issue because all the roads here are 45mph and above. Im in 5th gear instantly. My vstar in Akron I could never get out of 3rd. The bike calmed down at 68mph and above in 5th. 80mph was the sweet spot. So I think there is a mechanical side to the reported issues. Big thumper, torque cams, direct single butterfly. Add user and riding conditions then fueling reports vary. Ill report back at slower speeds lower gears steady cruise
Very good points Dno. I believe the OEM's got around the surging by using secondary throttle valve actuators. My VStrom has this. Explanation from Suzuki below:
The SDTV (suzuki dual throttle valve) system does a couple jobs. It's primary function when the engine is running is to manage intake velocity to keep the power curve smooth. As RPMs increase or decrease, they will open and shut to perform this function. The secondary function is to control the fast idle system.
Kawasaki also uses the Secondary actuators on their Ninja 1000's. Explains why it eliminated the surging and throttle cut abruptness.
Aftermarket tuners will surely come out with their G3 KLR tunes. I saw a video of the Leo Vince slip on. Very nice. An Australian guy on YouTube removed the G3 KLR snorkel. Sounds great without it!
In 5th gear the bike cruised so nicely. It did not act badly in 5 th at all
won't be long before there is a "flash" for the ECU.
Vstrom is the velvet version of the klr. Suzuki has addressed the concerns of klr owners well. Thumpers have great qualities and some not so great. Now on to see if I can pin point this more.
2 wheel dynoworks will have a flash very soon. Should be awesome i know they did great work on the t7's
grunkster that is great news, they are pretty close too
Ok I can totally create a bucking bronco. Or eliminate the issue. Goofy things I do when riding picked up from various bikes and conditions I think helps this situation.
Index finger rests on the brake lever
About 3/4" of my palm rests on the bar end
Sometimes I'll scrub brakes with locked throttle to slow down slightly ( mostly to keep chain tension)
Not afraid to feather a clutch either
The gen3 likes load. Ultra precision is needed in a small percent of closing and reopening of throttle. The variable cam throttle tube would probably help most riders with this and eliminate the some stiffness of the return spring issue. Solo ride upper 70° today at sea level winding out and bogging gears. The bike if anything fuels very well.
Sidenote no windshield and enjoyed that too.
Kinda curious about snorkel removal onthebackwheel did. This would maybe soften the torque hit of coming back on the throttle from closed.
I’ve been noticing this on cars a lot for the last 10 years. It’s very apparent going down an incline with the cruise control set. It seems to have gotten worse, across brands. I suspect as stated previously it is from getting that efficiency dialed in at the cost of comfort and performance.
One last part marine grade 89 octane was used for my report. No corn gas